44.the Thyroid Gland and the Thyroglossal Tract

7/27/2019 44.the Thyroid Gland and the Thyroglossal Tract

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44 The thyroid gland and the thyroglossal tractZYGMUNT H. KRUKOWSKI

Embryology

The thyroid gland deelo!" #rom the median b$d o# the !haryn% &the thyroglo""al

d$'t( )hi'h !a""e" #rom the #oramen 'ae'$m at the ba"e o# the tong$e to the i"thm$"

o# the thyroid. The $ltimobran'hial body )hi'h ari"e" #rom a dierti'$l$m o# the

#o$rth !haryngeal !o$'h o# ea'h "ide amalgamate" )ith the 'orre"!onding lateral

lobe. *ara#olli'$lar 'ell" &+,'ell"( are deried #rom the ne$ral 're"t and rea'h the

thyroid ia the $ltimobran'hial body. Re'ently- 'on"ideration ha" been gien to the

!o""ibility that "ome +,'ell" are o# endodermal rather than ne$ral 're"t origin. It i"

do$bt#$l )hether the bran'hial a!!arat$" it"el# 'ontrib$te" to the thyroid #olli'$lar

'ell".

S$rgi'al anatomy &ig" //.0 and //.1(

The normal gland )eigh" 12314 g. The #$n'tioning $nit i" the lob$le "$!!lied by a"ingle arteriole and 'on"i"ting o# 1/3/2 #olli'le" )hi'h are lined by '$boidal

e!itheli$m. The re"ting #olli'le 'ontain" 'olloid in )hi'h thyroglob$lin i" "tored. The

arterial "$!!ly i" ri'h- and e%ten"ie ana"tomo"e" o''$r bet)een the main thyroid

arterie" and bran'he" o# tra'heal and oe"o!hageal arterie". There i" an e%ten"ie

lym!hati' net)or5 )ithin the gland. 6ltho$gh "ome lym!h 'hannel" !a"" dire'tly to

the dee! 'eri'al node"- the "$b'a!"$lar !le%$" drain" !rin'i!ally to the 7$%tathyroid

node"- i.e. !retra'heal &8el!hi'(9 and !aratra'heal node"- and node" on the "$!erior

and in#erior thyroid ein"- and then'e to the dee! 'eri'al and media"tinal gro$! o#

node".

E'to!i' thyroid and anomalie" o# the thyroglo""al tra't

Some re"id$al thyroid ti""$e along the 'o$r"e o# the thyrogbo""al tra't i" not$n'ommon- and may be ling$al- 'eri'al or intrathora'i'. :ery rarely the )hole gland

i" e'to!i'.

;ing$al thyroid

Thi" #orm" a ro$nded ")elling at the ba'5 o# the tong$e at the #oramen 'ae'$m &ig"

//.< and //./( and itmay re!re"ent the only thyroid ti""$e !re"ent. It may 'a$"e

dy"!hagia- im!airment o# "!ee'h- re"!iratory ob"tr$'tion or hemorrhage. It i" be"t

treated by #$ll re!la'ement )ith thyro%ine )hen it "ho$ld get "maller- b$t e%'i"ion or

ablation )ith radioiodine i" "ometime" ne'e""ary.

Median &thyroglo""al( e'to!i' thyroid

Thi" #orm" a ")elling in the $!!er !art o# the ne'5 &ig. //./( and i" $"$ally mi"ta5en

#or a thyroglo""al 'y"t. 6gain- thi" may be the only normal thyroid ti""$e !re"ent.;ateral aberrant thyroid

There i" no eiden'e that aberrant thyroid ti""$e eer o''$r" in a lateral !o"ition

&Willi"(. =Normal thyroid ti""$e9 #o$nd laterally- "e!arate #rom the thyroid gland- m$"t

be 'on"idered and treated a" a meta"ta"i" in a 'eri'al lym!h node #rom an o''$lt

thyroid 'ar'inoma- almo"t inariably o# !a!illary ty!e. Str$ma oarii i" not e'to!i'

thyroid ti""$e- b$t !art o# an oarian teratoma. :ery rarely- neo!la"ti' 'hange o''$r"

or hy!erthyroidi"m deelo!".

Thyroglo""al'y"t

Thi" may be !re"ent in any !art o# the thyroglo""al tra't &ig. //.4(. The 'ommon

"it$ation"- in order o# #re>$en'y- are beneath the hyoid- in the region o# the thyroid

'artilage- and aboe the hyoid bone. S$'h a 'y"t o''$!ie" the midline- e%'e!t in the

region o# the thyroid 'artilage- )here the thyroglo""al tra't i" !$"hed to one "ide-


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$"$ally to the le#t. It i" to be remembered that the ")elling moe" $!)ard" on

!rotr$"ion o# the tong$e a" )ell a" on ")allo)ing be'a$"e o# the atta'hment o# the

tra't to the #oramen 'ae'$m.

6 thyroglo""al 'y"t "ho$ld be e%'i"ed be'a$"e in#e'tion i" ineitable- o)ing to the

#a't that the )all 'ontain" nod$le" o# lym!hati' ti""$e )hi'h 'omm$ni'ate by

lym!hati'" )ith the lym!h node" o# the ne'5. 6n in#e'ted 'y"t i" o#ten mi"ta5en #oran ab"'e"" and in'i"ed- )hi'h i" one )ay in )hi'h a thyroglo""al #i"t$la ari"e".

Thyroglo""al #i"t$la

Thyroglo""al #l"t$la &ig. //.?a- b( i" neer 'ongenital@ it#ollo)" in#e'tion or

inade>$ate remoal o# a thyroglo""al 'y"t. +hara'teri"ti'ally the '$taneo$" o!ening

o# "$'h a #i"t$la i" dra)n $!)ard" on !rotr$"ion o# the tong$e. 6 thyroglo""al #i"t$la

i" lined by 'ol$mnar e!itheli$m- di"'harge" m$'$"- and i" the "eat o# re'$rrent atta'5"

o# in#lammation.

Treatment. Ae'a$"e the thyroglo""al tra't i" "o 'lo"ely related to the body o# the hyoid

bone- thi" 'entral !art m$"t be e%'i"ed- together )ith the 'y"t or #i"t$la- or re'$rren'e

i" 'ertain. When the thyroglo""al tra't 'an be tra'ed $!)ard" to)ard" the #oramen

'ae'$m- itm$"t be e%'i"ed )ith the 'entral "e'tion o# the body o# the hyoid bone- anda 'entral 'ore o# ling$al m$"'le &Si"tr$n59" o!eration(.

*hy"iology. The hormone" tri,iodothyronine &T


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a'tion than TSH &0?31/ ho$r" er"$" 0.43$e"ted "ho$ld be the minim$m

ne'e""ary to rea'h a diagno"i" and #orm$late a management !lan. Only a "mall

n$mber o# !arameter" need" to be mea"$red a" a ro$tine altho$gh thi" may re>$ire

"$!!lementation or re!eat )hen in'on'l$"ie.

Ser$m thyroid hormone"

Ser$m TSH. TSH leel" 'an be mea"$red a''$rately do)n to ery lo) "er$m

'on'entration" and i# the "er$m TSH leel i" in the normal range it i" red$ndant to

mea"$re the T< and T/ leel". Inter!retation o# deranged TSH leel" ho)eer

de!end" on 5no)ledge o# the T< and T/ al$e" &Table //.0(. In the e$thyroid "tate-

T


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do"e radioiodine be#ore the "'an i" !er#ormed be'a$"e thyroid 'an'er 'annot 'om!ete

)ith normal thyroid ti""$e in the $!ta5e o# iodine.

Thyroid a$toantibodie"

Ser$m titre" o# antibodie" again"t thyroid !ero%ida"e and thyroglob$lin are $"e#$l in

determining the 'a$"e o# thyroid dy"#$n'tion and ")elling". 6$toimm$ne thyroiditi"

may be a""o'iated )ith thyroid to%i'ity- #ail$re or e$thyroid goitre. Titre" o# greaterthan 0@022 are 'on"idered "igni#i'ant b$t a !ro!ortion o# !atient" )ith hi"tologi'al

eiden'e o# lym!ho'yti' &a$toimm$ne( thyroiditi" i" "eronegatie.

Hy!othyroidi"m

6 "'heme #or 'la""i#ying hy!othyroidi"m i" gien in Table //.1.

+retini"m oetal or in#antile hy!othyroidi"m(

S!oradi' ' i" d$e to 'om!lete or near 'om!lete #ail$re o# thyroid deelo!ment &!artial

#ail$re 'a$"e" 7$enile my%oedema(@ the !arent" and other 'hildren may be !er#e'tly

normal. In endemi' area"- goitro$" 'retini"m i" 'ommon- and i" d$e to maternal and#oetal iodine de#i'ien'y. Immediate diagno"i" and treatment )ith thyro%ine )ithin a

#e) day" o# birth are e""ential i# !hy"i'al and mental deelo!ment are to be normal- or

i# #$rther deterioration i" to he !reented )hen damage ha" already o''$rred in $tero.

Hy!othyroidi"m o''$r" in I in /222 lie birth" and #or thi" rea"onin the UK- there i"

ro$tine bio'hemi'al "'reening o# neonate" #or hy!othyroidi"m $"ing TSH a""ay on a

"im!le heel,!ri'5 blood "am!le. Women $nder treatment )ith antithyroid dr$g" may

gie birth to a hy!othyroid in#ant.

6d$lt hy!othyroidi"m

The term my%oedema "ho$ld be re"ered #or "eere thyroid #ail$re and not a!!lied to

the m$'h 'ommoner mild thyroid de#i'ien'y.

The "ign" o# thyroid de#i'ien'y are@

D brady'ardia

D 'old e%tremitie"

D dry "5in and hair

D !eriorbital !$##ine""

D hoar"e oi'e

D brady5ine"i" 3"lo) moement"

D delayed rela%ation !ha"e o# an5le 7er5".

The "ym!tom" are@

D tiredne""

D mental lethargy

D 'old intoleran'e

D )eight gain

D 'on"ti!ation

D men"tr$al di"t$rban'e

D 'ar!al t$nnel "yndrome.

+om!ari"on o# the #a'ial a!!earan'e )ith a !reio$" !hotogra!h may be hel!#$l.

Thyroid #$n'tion te"t"


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Thyroid #$n'tion te"t" &Table //.0( "ho) lo) T/ and T< leel" )ith a high TSH

&e%'e!t in the rare eent o# !it$itary #ail$re(. High "er$m titre" o# antithyroid

antibodie" are 'hara'teri"ti' o# a$toimm$ne di"ea"e.

Treatment

Oral thyro%ine &2.0232.12 mg( a" a "ingle daily do"e &be'a$"e o# it" !rolonged

a'tion( i" '$ratie. +a$tion i" re>$ired in the elderly or tho"e )ith 'ardia' di"ea"e andthe re!la'ement do"e i" then 'ommen'ed at 2.24 mg daily and 'a$tio$"ly in'rea"ed. I#

a ra!id re"!on"e i" re>$ired- tri,iodothyronine &12 mg three time" a day( may be

$"ed.The "ign" and "ym!tom" o# hy!othyroidi"m are a''ent$ated. The #a'ial

a!!earan'e &ig. //.00( i" ty!i'al- and there i"o#ten "$!ra'lai'$lar !$##ine""- a malar

#l$"h and a yello) tinge to the "5in. My%oedema 'oma o''$r" in negle'ted 'a"e" and

'arrie" a high mortality the body tem!erat$re i" lo) and the !atient m$"t be )armed

"lo)ly@0 g o# intraeno$" hydro'orti"one &in diided do"e"( "ho$ld be gien daily-

and intraeno$" tri,iodothyronine in "lo)ly in'rea"ing do"e".

6$toimm$ne thyroiditi"

The "o,'alled !rimary or atro!hi' my%oedema i" no) 'on"idered to be an

a$toimm$ne di"ea"e "imilar to 'hroni' lym!ho'yti' &Ha"himoto9"( thyroiditi" &"eebelo)( b$t =)itho$t goitre #ormation #rom TSH "tim$lation. Ae'a$"e o# the delay in

diagno"i" the hy!othyroidi"m i" $"$ally m$'h more "eere than in goitro$"

a$toimm$ne thyroiditi".

8y"hormonogene"i" and goitrogen"

Geneti'ally determined de#i'ien'ie" in the enCyme" 'ontrolling the "ynthe"i" o#

thyroid hormone"- i# "eere- are re"!on"ible #or goitre #ormation )ith hy!othyroidi"m.

I# o# moderate degree- a "im!le &e$thyroid( goitre re"$lt". Similarly goitrogen" may

!rod$'e a goitre )ith- or )itho$t- hy!othyroidi"m.

6 n$mber o# nonendemi' goitro$" 'retin" ha" been born to a gro$! o# itinerant tin5er"

liing in S'otland )ho intermarry &H$t'hi"on- S'otland(. Thi" )a" d$e to a de#i'ien'y

o# the enCyme dehalogena"e. When thyroglob$lin i" bro5en do)n- $n'o$!led

iodotyro"ine" are liberated a" )ell a" T< and T/. They are bro5en do)n by the

enCyme dehalogena"e and the iodine retained )ithin the thyroid. I# dehalogena"e i"

de#i'ient- iodotyro"ine" !a"" into the blood- and are e%'reted in the $rine and thi" may

re"$lt in iodine de#i'ien'y and goitre #ormation. 6nother 'la""i' e%am!le o#

dy"hormonogene"i" i" *endred9" "yndrome- )here goitre i" a""o'iated )ith 'ongenital

dea#ne"". Thi" i" d$e to a de#i'ien'y o# !ero%ida"e- the enCyme re"!on"ible #or

organi#i'ation o# tra!!ed iodine. 8e#e't" in thyroglob$lin "ynthe"i" are al"o

re'ogni"ed in dy"hormonogene"i".

Thyroid enlargementThe normal thyroid gland i" im!al!able. The term goitre &;atin- g$tt$r the throat( i"

$"ed to de"'ribe generali"ed enlargement o# the thyroid gland. 6 di"'rete ")elling

&nod$le( in one lobe )ith no !al!able abnormality el"e)here i" termed an i"olated &or

"olitary( ")elling. 8i"'rete ")elling" )ith eiden'e o# abnormality el"e)here in the

gland are termed dominant.

6 "'heme #or 'ategori"ing thyroid enlargement i" gien in Table //.


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o# iodine &"ee belo)( b$t de#e'tie hormone "ynthe"i" !robably a''o$nt" #or many

"!oradi' goitre" &"ee belo)(.TSH i" not the only "tim$l$" to thyroid #olli'$lar 'ell

!roli#eration and other gro)th #a'tor" in'l$ding imm$noglob$lin" e%ert an in#l$en'e.

The heterogeneo$" "tr$'t$ral and #$n'tional re"!on"e in the thyroid re"$lting in

'hara'teri"ti' nod$larity may be d$e to the !re"en'e o# 'lone" o# 'ell" !arti'$larly

"en"itie to gro)th "tim$lation.Iodine de#i'ien'y

The daily re>$irement o# iodine i" abo$t 2.032.04 mg. In nearly all di"tri't" )here

"im!le goitre i" endemi'- there i" a ery lo) iodide 'ontent in the )ater and #ood.

Endemi' area" are in the mo$ntaino$" range"- "$'h a" the Ro'5y Mo$ntain"- the 6l!"-

the 6nde" and the Himalaya". In Great Aritain endemi' goitre i" #o$nd in the

Mendi!"- +hiltern"- +ot")old" and the *ennine 'hain o# 8erby"hire and Yor5"hire.

Endemi' goitre i" al"o #o$nd in lo)land area" )here the "oil la'5" iodide or the )ater

"$!!ly 'ome" #rom #ar a)ay mo$ntain range"- e.g. the Great ;a5e" o# North 6meri'a-

the *lain" o# ;ombardy- the Str$ma alley


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"tim$lation 'ea"e"- the goitre may regre""- b$t tend" to re'$r later at time" o# "tre""

"$'h a" !regnan'y. The goitre i" "o#t- di##$"e and may be'ome large eno$gh to 'a$"e

di"'om#ort. 6 'olloid goitre i" a late "tage o# di##$"e hy!er!la"ia )hen TSH

"tim$lation ha" #allen o## and )hen many #olli'le" are ina'tie and #$ll o# 'olloid &ig.

//.0$ire o!eration. O!eration may be indi'ated on

'o"meti' gro$nd" i# the goitre i" $n"ightly. Retro"ternal e%ten"ion )ith a't$al or

in'i!ient tra'heal 'om!re""ion i" an indi'ation #or o!eration- a" i" the !re"en'e o# a

dominant area o# enlargement )hi'h may be neo!la"ti'.

There i" a 'hoi'e o# "$rgi'al treatment@ &a( total thyroide'tomy )ith immediate and

li#e,long re!la'ement o# thyro%ine or &b( "ome #orm o# !artial re"e'tion to 'on"ere

"$##i'ient #$n'tioning thyroid ti""$e to "$b"ere normal #$n'tion )hil"t eliminatingthe ri"5 o# hy!o!arathyroidi"m )hi'h a''om!anie" total thyroide'tomy. *artial


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re"e'tion aim" to remoe the b$l5 o# the gland- leaing $! to g o# relatiely normal

ti""$e in ea'h remnant. The te'hni>$e i" e""entially the "ame a" de"'ribed #or to%i'

goitre- a" are the !o"to!eratie 'om!li'ation". More o#ten- ho)eer- the m$ltinod$lar

'hange i" a"ymmetri'ally di"trib$ted- )ith one lobe more "igni#i'antly inoled than

the other. Under the"e 'ir'$m"tan'e" total lobe'tomy on the more a##e'ted "ide i" the

a!!ro!riate management )ith either "$btotal re"e'tion or no interention on the le""a##e'ted "ide. In many 'a"e" the 'a$"atie #a'tor" !er"i"t and re'$rren'e i" li5ely.

Reo!eration #or re'$rrent nod$lar goitre i" more di##i'$lt and haCardo$" and #or thi"

rea"on many thyroid "$rgeon" #ao$r total thyroide'tomy in yo$nger !atient". When a

$nilateral lobe'tomy alone ha" been !er#ormed #or a"ymmetri' goitre- reo!eration i"

"traight#or)ard "ho$ld it be'ome ne'e""ary on the remaining lobe.

6#ter "$btotal re"e'tion itha" been '$"tomary to gie thyro%ine to "$!!re"" TSH

"e'retion )ith the aim o# !reenting re'$rren'e. Whether thi" i" either ne'e""ary or

e##e'tie i" $n'ertain- altho$gh the eiden'e o# bene#it in endemi' area" i" better than

el"e)here. There i" "ome eiden'e that re'$rren'e a#ter "$rgery may red$'e in "iCe

a#ter treatment )ith radioa'tie iodine.

+lini'ally di"'rete ")elling"8i"'rete thyroid ")elling" &thyroid nod$le"( are 'ommon and are !re"ent in


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I"oto!e "'an. I"oto!e "'anning $"ed to be the main"tay o# ine"tigation o# di"'rete

thyroid ")elling" to determine the #$n'tional a'tiity relatie to the "$rro$nding gland

a''ording to i"oto!e $!ta5e.

On "'anning- ")elling" are 'ategori"ed a" =hot9 &oera'tie(- =)arm9 &a'tie( or ='old9

&$ndera'tie(. 6 hot nod$le i" one that ta5e" $! i"oto!e- )hile the "$rro$nding thyroid

ti""$e doe" not. Here the "$rro$nding thyroid ti""$e i" ina'tie be'a$"e the nod$le i"!rod$'ing "$'h high leel" o# thyroid hormone" that TSH "e'retion i" "$!!re""ed. 6

)arm nod$le ta5e" $! i"oto!e and "o doe" normal thyroid ti""$e abo$t it. 6 'old

nod$le ta5e" $! no i"oto!e &ig. //.F(.

6bo$t 2 !er 'ent o# di"'rete ")elling" are 'old b$t only 04 !er 'ent !roe to be

malignant and the $"e o# thi" 'riterion a" an indi'ation #or o!eration la'5"

di"'rimination. Ro$tine i"oto!e "'anning ha" been abandoned e%'e!t )hen to%i'ity i"

a""o'iated )ith nod$larity.

Ultra"onogra!hy )a" #ormerly )idely $"ed a" a nonina"ie "$!!lement to 'lini'al

e%amination in determining the !hy"i'al 'hara'teri"ti'" o# thyroid ")elling". 6ltho$gh

$ltra"onogra!hy 'an demon"trate "$b'lini'al nod$larity and 'y"t #ormation- the

#ormer i" 'lini'ally irreleant and the latter a!!arent at a"!iration- )hi'h "ho$ld bero$tine in all di"'rete ")elling".

ine,needle a"!iration 'ytology &N6+(. N6+ ha" be'ome e"tabli"hed a" the

ine"tigation o# 'hoi'e in di"'rete thyroid ")elling". N6+ ha" e%'ellent !atient

'om!lian'e- i" "im!le and >$i'5 to !er#orm in the o$t,!atient de!artment and i"

readily re!eated. Thi" te'hni>$e- deelo!ed in S'andinaia "ome


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;arge,bore needle &Tr$'$t( bio!"y. Tr$'$t bio!"y ha" a high diagno"ti' a''$ra'y b$t

ha" !oor !atient 'om!lian'e and may be a""o'iated )ith 'om!li'ation" "$'h a" !ain-

bleeding- tra'heal and re'$rrent laryngeal nere damage. It ha" little a!!li'ation in

ro$tine a""e""ment e%'e!t in lo'ally adan'ed- "$rgi'ally $nre"e'table malignan'y

&either ana!la"ti' 'ar'inoma or lym!homa( )hen Tr$'$t bio!"y may aoid o!eration.

The main indi'ation #or o!eration i" the ri"5 o# neo!la"ia )hi'h in'l$de" #olli'$laradenoma a" )ell a" malignant ")elling". The rea"on #or ado'ating the remoal o# all

#olli'$lar neo!la"m" i" that iti" "eldom!o""ible to di"ting$i"h bet)een a #olli'$lar

adenoma and 'ar'inoma 'ytologi'ally. The di"tin'tion $"$ally de!end" on hi"tologi'al

eiden'e o# 'a!"$lar or a"'$lar ina"ion and N6+ 'annot ma5e thi" di"tin'tion-

altho$gh on o''a"ion 'ell$lar n$'lear #eat$re" may be "o abnormal a" to "$gge"t

malignant 'hange. On thi" ba"i"- "ome 42 !er 'ent o# i"olated and14 !er 'ent o#

dominant ")elling" "ho$ld be remoed on the gro$nd" o# neo!la"ia. Een )hen the

'ytology i" negatie- the age and "e% o# the !atient and the "iCe o# the ")elling may be

relatie indi'ation" #or "$rgery- e"!e'ially )hen a large ")elling i" re"!on"ible #or

"ym!tom". Some !atient" are ha!!ier to hae a ")elling remoed een )hen 'ytology

i" negatie.There are $"e#$l 'lini'al 'riteria to a""i"t in "ele'tion #or o!eration a''ording to the

ri"5 o# neo!la"ia and malignan'y. Hard te%t$re alone i" not reliable "in'e ten"e 'y"ti'

")elling" may be "$"!i'io$"ly hard b$t a hard- irreg$lar ")elling )ith any a!!arent

#i%ity- )hi'h i" $n$"$al- i" highly "$"!i'io$". Eiden'e o# re'$rrent laryngeal nere

!araly"i"- "$gge"ted by hoar"ene"" and a nono''l$"ie 'o$gh- and 'on#irmed by

indire't laryngo"'o!y- i" almo"t !athognomoni'. 8ee! 'eri'al lym!hadeno!athy

along the internal 7$g$lar ein in a""o'iation )ith a 'lini'ally "$"!i'io$" ")elling i"

almo"t diagno"ti' o# !a!illary 'ar'inoma. In mo"t !atient"- ho)eer- "$'h #eat$re" are

ab"ent b$t there are ri"5 #a'tor" a""o'iated )ith "e% and age. The in'iden'e o# thyroid

'ar'inoma in )omen i" abo$t three time" that in men- b$t a di"'rete ")elling in a male

i" m$'h more li5ely to be malignant than in a #emale and it i" "eldom 7$"ti#iable to

aoid remoing "$'h a ")elling in a man. The ri"5 o# 'ar'inoma i" in'rea"ed at either

end o# the age range and a di"'rete ")elling in a teenager o# either "e% m$"t be

!roi"ionally diagno"ed a" 'ar'inoma. The ri"5 in'rea"e" a" age adan'e" beyond 42

year"- and more "o in male".

Thyroid'y"t"

Ro$tine N6+ &or $ltra"onogra!hy( "ho)" that oer


11/28

Retro"ternal goitre

:ery #e) retro"ternal goitre" ari"e #rom e'to!i' thyroid ti""$e mo"t ari"e #rom the

lo)er !ole o# a nod$lar goitre. I# the ne'5 i" "hort and the !retra'heal m$"'le" are

"trong- a" in men- the negatie intrathora'i' !re""$re tend" to dra) the"e nod$le" into

the "$!erior media"tin$m.

+lini'al #eat$re"6 retro"ternal goitre i" o#ten "ym!tomle"" and i" di"'oered on a ro$tine 'he"t

radiogra!h. There may- ho)eer- be "eere "ym!tom"@

dy"!noea- !arti'$larly at night- 'o$gh and "tridor &har"h "o$nd on in"!iration(. Many

o# the"e !atient" may attend a 'he"t 'lini' )ith a diagno"i" o# a"thma be#ore the tr$e

nat$re o# the !roblem i" di"'oered

D dy"!hagia

D engorgement o# ne'5 ein" and "$!er#i'ial ein" on the 'he"t )all. In "eere 'a"e"

there may be ob"tr$'tion o# the "$!erior ena 'aa &ig. //.10(

D re'$rrent nere !araly"i" i" rare. The goitre may al"o be malignant or to%i'.

Radiogra!h" "ho) a "o#t,ti""$e "hado) in the "$!erior media"tin$m 3 "ometime"

)ith 'al'i#i'ation 3 and o#ten 'a$"ing deiation and 'om!re""ion o# the tra'hea &ig.//.0/(. Radio,gra!h" o# the thora'i' inlet gie better de#inition than a 'he"t

radiogra!h. Signi#i'ant tra'heal 'om!re""ion and ob"tr$'tion may be demon"trated

ob7e'tiely by a #lo)3ol$me loo! !$lmonary #$n'tion te"t in )hi'h the rate o# #lo)

i" !lotted again"t the ol$me o# air in"!ired and then e%!ired. 8eterioration in #lo)

d$e to in'rea"e in tra'heal 'om!re""ion either a'$tely or in the long term may be $"ed

to monitor !rogre""ion o# the di"ea"e and indi'ate the need #or "$rgery. The 'hange"

are reer"ed by o!eration &ig. //.11(.

Treatment

I# ob"tr$'tie "ym!tom" are !re"ent in a""o'iation )ith thyroto%i'o"i" it i" $n)i"e to

treat a retro"ternal goitre )ithantithyroid dr$g" or radioiodine a" the"e may enlarge

the goitre. Re"e'tion 'an almo"t al)ay" be 'arried o$t #rom the ne'5 and a midline

"ternotomy i" hardly eer ne'e""ary. The 'eri'al !art o# the goitre "ho$ld #ir"t be

mobili"ed by ligation and dii"ion o# the "$!erior thyroid e""el"- and by ligat$re and

dii"ion o# the middle thyroid ein" and the in#erior thyroid artery. The retro"ternal

goitre 'an then be deliered by tra'tion and #inger mobili"ation. Haemorrhage i"

rarely a !roblem be'a$"e the goitre ta5e" it" blood "$!!ly )ith it #rom the ne'5. The

re'$rrent laryngeal nere "ho$ld be identi#ied i# !o""ible be#ore deliering the

retro"ternal goitre- a" it may be abnormally di"!la'ed and i" !arti'$larly $lnerable to

in7$ry #rom tra'tion or tearing. I# a large m$ltinod$lar goitre 'annot be deliered

inta't #rom the retro"ternal !o"ition it may be bro5en )ith the #inger" and deliered

!ie'emeal- b$t thi" "ho$ld neer he done i# the le"ion i" "olitary and there i" the!o""ibility o# 'ar'inoma.

Hy!erthyroidi"m

Thyroto%i'o"i"

The term thyroto%i'o"i" i" retained be'a$"e hy!erthyroidi"m- i.e. "ym!tom" d$e to a

rai"ed leel o# 'ir'$lating thyroid hormone"- i" not re"!on"ible #or all mani#e"tation"

o# the di"ea"e.

+lini'al ty!e" are@

D di##$"e to%i' goitre &Grae"9 di"ea"e(

Dto%i' nod$lar goitre

Dto%i' nod$le

Dhy!erthyroidi"m d$e to rarer 'a$"e".8i##$"e to%i' goitre


12/28

Grae"9 di"ea"e 3 a di##$"e a"'$lar goitre a!!earing at the "ame time a" the

hy!erthyroidi"m- $"$ally in the yo$nger )oman and #re>$ently a""o'iated )ith eye

"ign". The "yndrome i" that o# !rimary thyroto%i'o"i" &ig. //.1


13/28

thyroto%i'o"i" not d$e to hy!erthyroidi"m !er Se- e.g. orbital !ro!to"i"-

o!hthalmo!legia and !retibial my%oedema- may o''$r in !rimary thyroto%i'o"i".

In "e'ondary thyroto%i'o"i" the goitre i" nod$lar. The on"et i" in"idio$" and may

!re"ent )ith 'ardia' #ail$re or atrial #ibrillation. It i" 'hara'teri"ti' that the

hy!erthyroidi"m i" not "eere. Eye "ign" other than lid lag and lid "!a"m &d$e to

hy!erthyroidi"m( are ery rare.+ardia' rhythm. 6 #a"t heart rate- )hi'h !er"i"t" d$ring "lee!- i" 'hara'teri"ti'.

+ardia' arrhythmia" are "$!erim!o"ed on the "in$" ta'hy'ardia a" the di"ea"e

!rogre""e"- and they are 'ommoner in older !atient" )ith thyroto%i'o"i" be'a$"e o#

the !realen'e o# 'oin'idental heart di"ea"e. Stage" o# deelo!ment o# thyroto%i'

arrhythmia" are@

D m$lti!le e%tra"y"tole"

D !aro%y"mal atrial ta'hy'ardia

D !aro%y"mal atrial #ibrillation

D !er"i"tent atrial #ibrillation- not re"!on"ie to digo%in.

Myo!athy. Wea5ne"" o# the !ro%imal limb m$"'le" i" 'ommonly #o$nd i# loo5ed

#or. Seere m$"'$lar )ea5ne"" &thyroto%i' myo!athy( re"embling mya"thenia grai"o''$r" o''a"ionally. Re'oery !ro'eed" a" hy!erthyroidi"m i" 'ontrolled.

Eye "ign". Some degree o# e%o!hthalmo" i" 'ommon &ig. //.1


14/28

normal range. 6 thyroid "'an i" e""ential in the diagno"i" o# an a$tonomo$" to%i'

nod$le.

Thyroto%i'o"i" "ho$ld al)ay" be 'on"idered in@

D 'hildren )ith a gro)th "!$rt- behaio$r !roblem" or myo!athy

Dta'hy'ardia or arrhythmia in the elderly

D$ne%!lained diarrhoeaD lo"" o# )eight.

*rin'i!le" o# treatment o# thyroto%i'o"i"

Non"!e'i#i' mea"$re" are re"t and "edation and- in e"tabli"hed thyroto%i'o"i"- "ho$ld

be $"ed only in 'on7$n'tion )ith "!e'i#i' mea"$re" 3the $"e o# antithyroid dr$g"-

"$rgery and radioiodine.

6ntithyroid dr$g"

Tho"e in 'ommon $"e are 'arbimaCole and !ro!ylthio$ra'il. Aeta,adrenergi' blo'5er"-

"$'h a" !ro!ranolol and nadolol- may al"o be $"ed. Iodide"- on'e tho$ght to red$'e

the a"'$larity o# the thyroid- "ho$ld only be $"ed a" immediate !reo!eratie

!re!aration in the 02 day" be#ore "$rgery. 6ntithyroid dr$g" are $"ed to re"tore the

!atient to a e$thyroid "tate and to maintain thi" #or a !rolonged !eriod in the ho!e thata !ermanent remi""ion )ill o''$r- i.e. that !rod$'tion o# T"6b )ill dimini"h or 'ea"e.

It "ho$ld be noted that antithyroid dr$g" 'annot '$re a to%i' nod$le. The oera'tie

thyroid ti""$e i" a$tonomo$" and re'$rren'e o# the hy!erthyroidi"m i" 'ertain )hen

the dr$g i" di"'ontin$ed.

6dantage"

No "$rgery and no $"e o# radioa'tie material".

8i"adantage"

DTreatment i" !rolonged and the #ail$re rate a#ter a 'o$r"e o# 0.431 year" i" at lea"t

42 !er 'ent. Re'ently there ha" been a trend to)ard" the $"e o# "horter 'o$r"e"

&?month"( o# the"e dr$g".

DIt i" im!o""ible to !redi't )hi'h !atient i" li5ely to go into a remi""ion. 6ttem!t"

hae been made to !redi't )hi'h !atient" might rela!"e a#ter a ?,month 'o$r"e o#

antithyroid dr$g" on the ba"i" o# h$man le$'o'yte antigen &H;6( "tat$" and the

!re"en'e o# T"6b !rod$'tion.L

DSome goitre" enlarge and be'ome ery a"'$lar d$ring treatment 3een i# thyro%ine

i" gien at the "ame time. Thi" i" !robably d$e to T"6b "tim$lation d$ring the

!rolonged 'o$r"e o# treatment and not a dire't e##e't o# the dr$g.

D:ery rarely- there i" a dangero$" dr$g rea'tion- e.g. agran$lo'yto"i" or a!la"ti'

anaemia. In the eent o# agran$lo'yto"i"- the !atient "ho$ld be in"tr$'ted to

di"'ontin$e treatment- i# a "ore throat deelo!"- $ntil the )hite 'ell 'o$nt ha" been

'he'5ed.

Initially- 02 mg o# 'arbimaCole/ i" gien three or #o$r time" a day- and there i" a

latent interal o# F30/ day" be#ore any 'lini'al im!roement i" a!!arent. It i" mo"t

im!ortant to maintain a high 'on'entration o# the dr$g thro$gho$t the 1/ ho$r" by

"!a'ing the do"e" at , or ?,ho$rly interal". When the !atient be'ome" e$thyroid- a

maintenan'e do"e o# 4 mg t)o or three time" a day i" gien #or another 0130

month". I# tri,iodothyronine &12 7ig$! to #o$r time" daily( or thyro%ine &2.0 mg daily(

i" gien in 'on7$n'tion )ith anti,thyroid dr$g"- there i" le"" danger o# !rod$'ing

iatrogeni' thyroid in"$##i'ien'y or an in'rea"e in the "iCe o# the goitre &=blo'5 and

re!la'ement treatment9(.

S$rgery


15/28

In di##$"e to%i' goitre and to%i' nod$lar goitre )ith oera'tie internod$lar ti""$e-

"$rgery '$re" by red$'ing the ma"" o# oera'tie ti""$e. +$re i" !robable i# the

thyroid ti""$e 'an be red$'ed belo) a 'riti'al ma"". Thi" may re"$lt in a red$'tion o#

T"6b or it may be that 'ir'$lating T"6b- ho)eer high it" leel- 'an only !rod$'e

limited hy!ertro!hy and hy!er!la"ia )hen the ma"" o# thyroid ti""$e i" "mall. In the

a$tonomo$" to%i' nod$le- and in to%i' nod$lar goitre )ith oera'tie a$tonomo$"to%i' nod$le"- "$rgery '$re" by remoing all o# the oera'tie thyroid ti""$e@ thi"

allo)" the "$!!re""ed normal ti""$e to #$n'tion again.

6dantage"

The goitre i" remoed- the '$re i" ra!id and the '$re rate i" high i# "$rgery ha" been

ade>$ate.

8i"adantage"

DRe'$rren'e o# thyroto%i'o"i" o''$r" in a!!ro%imately 4 !er 'ent o# 'a"e".

DEery o!eration 'arrie" a morbidity b$t )ith "$itable !re!aration and an e%!erien'ed

"$rgeon the mortality i" negligible.

D*o"to!eratie thyroid in"$##i'ien'y o''$r" in 123/4 !er 'ent o# 'a"e".

D;ong,term #ollo),$! i" highly de"irable a" the #e) !atient" )ho deelo! re'$rren'emay do "o at any time in the #$t$re. In addition- altho$gh it i" $"$ally a!!arent )ithin

a year or t)o- thyroid #ail$re may al"o he a late deelo!ment.

D*arathroid in"$##i'ien'y@ thi" "ho$ld he !ermanent in le"" than 2.4 !er 'ent.

Radioiodine

Radioiodine4 de"troy" thyroid 'ell" and- a" in thyroide'tomy- red$'e" the ma"" o#

#$n'tioning thyroid ti""$e to belo) a 'riti'al leel.

6dantage"

No "$rgery and no !rolonged dr$g thera!y.

8i"adantage"

DI"oto!e #a'ilitie" m$"t be aailable.

DThere i" a high and !rogre""ie in'iden'e o# thyroid in"$##i'ien'y )hi'h may rea'h

F432 !er 'ent a#ter 02 year". Thi" i" d$e to "$blethal damage to tho"e 'ell" not

a't$ally de"troyed by the initial treatment and thi" eent$ally 'a$"e" #ail$re o# 'ell$lar

re!rod$'tion.

DInde#inite #ollo),$! i" e""ential.

There i" no 'onin'ing eiden'e that radioiodine ha" been re"!on"ible #or geneti'

damage- le$5aemia- damage to the #oet$" i# gien inadertently in early !regnan'y- or

'ar'inoma in the ad$lt. In "ome 'lini'"- radioiodine i" gien to almo"t all !atient" oer

the age o# 14- i.e. )hen deelo!ment i" 'om!lete. ollo),$! re>$irement" are red$'ed

i# a total ablatie do"e o# radioiodine i" admini"tered #ollo)ed by ro$tine re!la'ement

treatment )ith thyro%ine. In the UK- rel$'tan'e to !re"'ribe radioiodine $nder the ageo# /4 ha" #aded. The do"e o# radioiodine arie" bet)een . Re"!on"e

i" "lo)- b$t a "$b"tantial im!roement i" to he e%!e'ted in 301 )ee5". 6''$rate

do"age i" di##i'$lt and- "ho$ld there be no 'lini'al im!roement a#ter 01 )ee5"- a

#$rther do"e i" gien. T)o or more do"e" are ne'e""ary in 123< 2 !er 'ent o# 'a"e".

+hoi'e o# thera!e$ti' agent

Ea'h 'a"e m$"t be 'on"idered indiid$ally. Aelo) are li"ted g$iding !rin'i!le" on the

mo"t "ati"#a'tory treatment #or a !arti'$lar to%i' goitre at a !arti'$lar age the"e m$"t

ho)eer be modi#ied a''ording to the #a'ilitie" aailable and the !er"onality-

intelligen'e and )i"he" o# the indiid$al !atient- b$"ine"" or #amily 'ommitment" and

any other 'oe%i"tent medi'al or "$rgi'al 'ondition.

8i##$"e to%i' goitre


16/28

Oer /4@ radioiodine. Under /4@ "$rgery #or the large goitre- antithyroid dr$g" #or the

"mall goitre. 6" mentioned aboe- radioiodine i" being in'rea"ingly $"ed in yo$nger

!atient"- !arti'$larly )hen their #amilie" are 'om!lete.

;arge goitre" are $n'om#ortable and remi""ion )ith antithyroid dr$g" i" le"" li5ely

than in the "mall goitre.

To%i' nod$lar goitreS$rgery. To%i' nod$lar goitre doe" not re"!ond a" )ell or a" ra!idly to radioiodine or

antithyroid dr$g" a" doe" a di##$"e to%i' goitre- and the goitre it"el# i" o#ten large and

$n'om#ortable and enlarge" "till #$rther )ith antithyroid dr$g".

To%i' nod$le

S$rgery or radioiodine. Re"e'tion i" ea"y- 'ertain and )itho$t morbidity. Radioiodine

i" a good alternatie oer the age o# /4 be'a$"e the "$!!re""ed thyroid ti""$e doe" not

ta5e $! iodine and there i" th$" no ri"5 o# delayed thyroid in"$##i'ien'y.

Re'$rrent thyroto%i'o"i" a#ter "$rgery

In general radioiodine- b$t antithyroid dr$g" may be $"ed in yo$ng )omen intending

to hae 'hildren. $rther "$rgery ha" no !la'e.

ail$reo# !reio$" treatment )ith antithyroid dr$g" or radioiodine. S$rgery or thyroidablation )ith 01


17/28

*ro!to"i" o# re'ent on"et. There i" a 'onentional ie) that to terminate

thyroto%i'o"i" abr$!tly by thyroide'tomy or radioiodine )hen !ro!to"i" i" re'ent may

ind$'e malignant e%o!hthalmo". Whil"t there i" no real !roo# o# thi" iti" rea"onable to

treat the"e !atient" )ith anti,thyroid dr$g" $ntil the !ro!to"i" ha" been "tati' #or ?

month"

Hy!erthyroidi"m d$e to other 'a$"e"Thyroto%i'o"i" #a'titia. &U"$ally "een in health ='ran5"9 or tho"e gien thyroid e%tra't

a" =a toni'9.( Hy!erthyroidi"m may he ind$'ed by ta5ing thyro%ine- b$t only i# the

do"age e%'eed" the normal re>$irement" o# 2.0432.14 mg a day. 8o"e" belo) the

normal re>$irement" "im!ly "$!!re"" normal hormone !rod$'tion by the thyroid.

'retini"m

od,Aa"edo) thyroto%i'o"i". &od German #or iodine Aa"edo). In E$ro!ean

'o$ntrie" di##$"e to%i' goitre i" o#ten 'alled Aa"edo)9" di"ea"e.( ;arge do"e" o#

iodide gien to a hy!er!la"ti' endemi' goitre )hi'h i" iodine aid may

!rod$'etem!orary hy!erthyroidi"m- and ery o''a"ionally !er"i"tent hy!erthyroidi"m.

In "$b a'$te or a'$te #orm" o# a$toimm$ne thyroiditi" or o# de $erain9" thyroiditi"

&"ee later(- mild hy!erthyroidi"m mayo''$r in the early "tage" d$e to liberation o#thyroid hormone" #rom damaged ti""$e.

6 large ma"" o# "e'ondary 'ar'inoma )ill rarely !rod$'e "$##i'ient hormone to

ind$'e mild hy!erthyroidi"m.

Neonatal thyroto%i'o"i" o''$r" inbabie" hornto hy!erthyroid mother" or to e$thyroid

mother" )hohae had thyroto%i'o"i". High T"6b titre" are !re"ent in both motherand

'hild be'a$"e T"6b 'an 'ro"" the !la'ental barrier. The hy!erthyroidi"m grad$ally

"$b"ide" a#ter


18/28

Aeta,blo'5er" a't on the target organ" and not on the gland it"el#. *ro!ranolol inhibit"

the !eri!heral 'oner"ion o# 0/ to0


19/28

o!eratie #ield. It "ho$ld #ir"t he "o$ght belo) the leel o# the in#erior thyroid artery

a" it !a""e" obli>$ely $!)ard" and #or)ard". Thi" 'o$r"e &ig. //.$e to the

tra'hea and oe"o!hag$"- i" a''ent$ated by mobili"ation o# the thyroid lobe. I# not

immediately "een- the nere 'an $"$ally be !al!ated a" a ta$t "trand. 6t a higher leel

the nere lie" bet)een the bran'he" o# the in#erior thyroid artery. The nere !a""e"

into the laryn% immediately behind the in#erior e$ro o# the thyroid 'artilage )hi'h i"there#ore a ery im!ortant landmar5. I# the right nere 'annot he #o$nd in it" $"$al

'o$r"e- an anomalo$" &nonre'$rrent( nere- !re"ent in 0 !er 'ent o# 'a"e"- "ho$ld he

"$"!e'ted thi" ari"e" #rom the ag$" tr$n5 and $"$ally !a""e" #rom behind the 'arotid

"heath- '$ring medially- #or)ard" and $!)ard"- and may be mi"ta5en #or the in#erior

thyroid artery. The !arathyroid gland" are !rote'ted by identi#i'ation on 'are#$l

in"!e'tion o# the goitre be#ore re"e'tion and by aoiding ligat$re" and "$t$re" 'lo"e to

the hil$m o# identi#ied gland". The $"e o# diathermy in thi" area "ho$ld he aoided a"

heat 'ond$'tion may dea"'$lari"e the !arathyroid" or damage the re'$rrent laryngeal

nere" &ig. //.01(. I# a !arathyroid gland i" inadertently e%'i"ed or dea"'$lari"ed-

it "ho$ld he a$totran"!lanted in "eeral #ragment" )ithin the "ternoma"toid m$"'le.

S$btotal re"e'tion o# ea'h lobe i" 'arried o$t- leaing a remnant o# bet)een / and 4 gon ea'h "ide. 6b"ol$te haemo"ta"i" i" "e'$red byligation o# indiid$al e""el" and

by"$t$re o# the thyroid remnant" to the tra'heal #a"'ia. The !retra'heal m$"'le" amid

'eri'al #a"'ia are "$t$red and the )o$nd i" 'lo"ed )ith or )itho$t "$'tion drainage to

the dee! 'eri'al "!a'e.

*o"to!eratie 'om!li'ation"

Haemorrhage. 6 ten"ion haematoma dee! to the 'eri'al #a"'ia &ig. //.


20/28

ri"5 and re'oer" in < )ee5" to < month". *ermanent !araly"i" i" e%tremely rare i# the

nere ha" been identi#ied at o!eration.

Thyroid in"$##i'ien'y. Thi" $"$ally o''$r" )ithin 1 year"- b$t it i" "ometime" delayed

#or 4 year" or more. It i" o#ten in"idio$" and di##i'$lt to re'ogni"e. The in'iden'e i"

'on"iderably higher than $"ed to he tho$ght and #ig$re" o# 123/4 !er 'ent hae been

re!orted a#ter o!eration" on di##$"e to%i' goitre" and to%i' nod$lar goitre" )ithinternod$lar hy!er!la"ia. It re!re"ent" a 'hange in the a$toimm$ne re"!on"e #rom

"tim$lation to de"tr$'tion o# thyroid 'ell". There i"- ho)eer- a de#inite relation"hi!

bet)een the e"timated )eight o# the thyroid remnant and the deelo!ment o# thyroid

#ail$re a#ter "$btotal thyroide'tomy #or Grae"9 di"ea"e. Thyroid in"$##i'ien'y i" rare

a#ter "$rgery #or a to%i' adenoma be'a$"e there i" no a$toimm$ne di"ea"e !re"ent.

*arathyroid in"$##i'ien'y i" d$e to remoal o# !arathyroid gland"- or in#ar'tion

thro$gh damage to the !arathyroid end,artery o#ten both #a'tor" o''$r together.

:a"'$lar in7$ry i" !robably #ar more im!ortant than inadertent remoal. The

in'iden'e o# thi" 'ondition "ho$ld be le"" than 2.4 !er 'ent and mo"t 'a"e" !re"ent

dramati'ally 134 day" a#ter o!eration- b$t ery rarely the on"et i" delayed #or 13$ately !re!ared #or thyroide'tomy- and i" no)

e%tremely rare. :ery rarely- a thyroto%i' !atient !re"ent" in a 'ri"i" amid thi" may

#ollo) an $nrelated o!eration. Sym!tomati' and "$!!ortie treatment i" #or

dehydration- hy!er!yre%ia and re"tle""ne"". Thi" re>$ire" the admini"tration o#

intraeno$" #l$id"- 'ooling the !atient )ith i'e !a'5"- admini"tration o# o%ygen-

di$reti'" #or 'ardia' #ail$re- digo%in #or $n'ontrolled atrial #ibrillation- "edation and

intraeno$" hydro'orti"one. S!e'i#i' treatment i" by 'arbimaCole 02312 mg ?,

ho$rly- ;$gol9" iodine 02 dro!" ,ho$rly by mo$th or "odi$m iodide 0 g

intraeno$"ly &i..(. *ro!ranolol /2 mg ?,ho$rly orally )ill blo'5 ader"e beta,

adrenergi' e##e't". Thi" agent may be gien by 'are#$l intraeno$" admini"tration &0

31 mg( $nder !re'i"e ele'tro'ardiogra!hi' 'ontrol.

Wo$nd in#e'tion. 6 "$b'$taneo$" or dee! 'eri'al ab"'e"" "ho$ld he drained.

Hy!ertro!hi' or 5eloid "'ar i" more li5ely to #orm i# the in'i"ion oerlie" the "tern$m.

Intradermal in7e'tion" &I#'orti'o"teroid "ho$ld he gien at on'e and re!eated monthly

i# ne'e""ary.

Stit'h gran$loma. Thi" may o''$r )ith or )itho$t "in$" #ormation and i" "een a#ter

the $"e o# nonab"orbable "$t$re material. 6b"orbable ligat$re" and "$t$re" m$"t be

$"ed thro$gho$t thyroid "$rgery. Some "$rgeon" $"e a "$b'$ti'$lar ab"orbable "5in

"$t$re rather than the traditional "5in 'li!" or "ta!le". S5in "ta!le" "ho$ld be remoed

in le"" than / ho$r".*o"to!eratie 'are

Indire't laryngo"'o!y ha" been adi"ed a" a ro$tine be#ore leaing ho"!ital.

6lternatiely- it may he aoided )hen the oi'e i" normal and the 'o$gh

o''l$"ie.6bo$t 14 !er 'ent o# !atient" deelo! tran"ient hy!o'al'aemia and- i#

a""o'iated "ym!tom" are "eere- intraeno$" 'al'i$m gl$'onate or oral 'al'i$m may

be ne'e""ary- altho$gh thi" i" $n$"$al. To "'reen #or !arathyroid in"$##i'ien'y- the

"er$m 'al'i$m "ho$ld be mea"$red at the #ir"t reie) attendan'e /3? )ee5" a#ter

o!eration

6#ter o!eration- "tability in term" o# thyroid #$n'tion ta5e" time. It i" im!ortant that

bio'hemi'al &"$b'lini'al( thyroid #ail$re "ho$ld not he aim indi'ation #or treatment

d$ring the #ir"t year a" the ma7ority o# !atient" )ith early "$b'lini'al #ail$re- )hi'h i"'ommon- $ltimately regain" normality. Een )hen there are 'lini'al #eat$re" o#


21/28

#ail$re- thyro%ine "ho$ld he )ithheld i# !o""ible d$ring the #ir"t ? month". Mo"t

!atient" )ho deelo! thyroid #ail$re do "o )ithin the #ir"t 1 year"- b$t there i" a

'ontini$ing in'iden'e therea#ter. Re'$rrent thyroto%i'o"i" may o''$r at any time a#ter

o!eration. ollo),$! "ho$ld there#ore he #or li#e.

On'e a "table "it$ation ha" been a'hieed- #ollo),$! a#ter thyroid "$rgery may be

'arried o$t by an a$tomated 'om!$ter,a'tiated "y"tem. S$'h "y"tem" in S'otland andWale" hae been "ho)n to be e%tremely 'o"t,e##e'tie and dramati'ally red$'e the

n$mber o# !atient attendan'e" at the thyroid 'lini'.

The in'iden'e" >$oted #or thyroid #ail$re &123/4 !er 'ent( and re'$rrent

thyroto%i'o"i" &4 !er 'ent( a#ter "$btotal thyroide'tomy #or Grae"9 di"ea"e re#er to

UK e%!erien'e arid may be di##erent el"e)here in the )orld. In i'eland- #or e%am!le-

an area o# high dietary iodine inta5e- the in'iden'e o# thyroid #ail$re i" m$'h lo)er

amid that o# re'$rrent to%i'ity m$'h higher than in the UK.

Neo!la"m" o# the thyroid

Thyroid neo!la"m" are 'la""i#ied in Table //.4.Aenign t$mo$r"

olli'$lar adenoma" !re"ent a" 'lini'ally "olitary nod$le" and the di"tin'tion bet)een

a #olli'$lar 'ar'inoma and an adenoma 'an only be made by hi"tologi'al e%amination@

in the adenoma there i" no ina"ion o# the 'a!"$le or o# !eri'a!"$lar blood e""el".

Treatment i"- there#ore- by )ide e%'i"ion 3!re#erably a lobe'tomy. The remaining

thyroid ti""$e i" normal "o that !rolonged #ollo) $! i" $nne'e""ary. It i" do$bt#$l

)hether there i" "$'h an entity a" a !a!illaryadenoma and all !a!illary t$mo$r" "ho$ld

be 'on"idered a"malignant een i# en'a!"$lated.

Malignant t$mo$r"

The a"t ma7ority o# !rimary gro)th" i" 'ar'inoma" &Table //.?(. 8$nhill 'la""i#ied

them hi"tologi'ally a" di##erentiated and $ndi##erentiated@ and the di##erentiated

'ar'inoma" are no) "$bdiided into #olli'$lar and !a!illary. Se'ondary gro)th" are

rare b$t blood,borne meta"ta"e" o''$r &ig" //.$ently #ollo)" a''idental

irradiation o# the thyroid in 'hildhoodF. The in'iden'e o# #olli'$lar 'ar'inoma i" high

in endemi' goitro$" area"- !o""ibly o)ing to TSH "tim$lation. Malignant lym!homa"

'an !re"ent in a !atient 5no)n to hae a$toimm$ne thyroiditi"- "o that the

lym!ho'yti' in#iltration in the a$toimm$ne !ro'e"" may be an aetiologi'al #a'tor.Indeed- iti" li5ely that all lym!homa" o# the thyroid ari"e in gland" a##e'ted by "$'h

thyroiditi".

+lini'al #eat$re" o# thyroid neo!la"m"

The ann$al in'iden'e i" abo$t


22/28

een )hen lym!hati' meta"ta"e" are !re"ent &"o,'alled lateral aberrant thyroid(. *ain-

o#ten re#erred to the ear- i" #re>$ent in in#iltrating gro)th".

8iagno"i" o# thyroid neo!la"m"

8iagno"i" i" obio$" on 'lini'al e%amination in mo"t 'a"e" o# ana!la"ti' 'ar'inoma-

altho$gh Riedel9" thyroiditi" &"ee later( i" indi"ting$i"hable. The lo'ali"ed #orm" o#

gran$lomato$" thyroiditi" and lym!hadenoid goitre may "im$late 'ar'inoma. It i" notal)ay" ea"y to e%'l$de a 'ar'inoma in a m$ltinod$lar goitre- and "olitary nod$le"-

!arti'$larly in the yo$ng male- are al)ay" "$"!e't. ail$re to ta5e $! radio,iodine i"

'hara'teri"ti' o# almo"t all thyroid 'ar'inoma" only ery rarely )ill di##erentiated

'ar'inoma &!rimary or "e'ondary( ta5e $! 01


23/28

*rogno"i" in di##erentiated thyroid 'ar'inoma

The !rogno"i" o# di##erentiated thyroid 'ar'inoma - altho$gh in#l$en'ed byhi"tologi'al

ty!e- i" m$'h more de!endent onage- the !re"en'e o# e%trathyroidal "!read or ma7or

'a!"$lar tran"gre""ion &in #olli'$lar 'ar'inoma(- and the "iCe o# the t$mo$r. Re'ently-

"eeral "'oring "y"tem" ba"ed on m$lti,#a'torial analy"i" o# ri"5 #a'tor" #rom

retro"!e'tiely gathered data hae been dei"ed. On the ba"i" o# age- t$mo$r "!read-"iCe and hi"tology- the"e allo) "e!aration o# !atient" into lo),and high,ri"5 gro$!"

)ith 14,year mortality rate" o# 1 !er 'ent and /? !er 'ent- re"!e'tiely. With regard to

age- the !rogno"i" i" m$'h )or"e in male" oer the age o# /2 year" and in #emale"

oer 42 year". 8i"tant meta"tati' di"ea"e i" obio$"ly an ader"e !rogno"ti' #a'tor b$t

lym!h node meta"ta"e" are not a""o'iated )ith )or"e !rogno"i". 8e#inition" o# lo),

and high,ri"5 gro$!" ba"ed on data #rom the ;ahey +lini' are gien in Table //..

*atient" in the lo),ri"5 gro$! a''o$nt #or B2 !er 'ent o# 'a"e" o# di##erentiated thyroid

'ar'inoma.

S$rgi'al treatment

There i" 'ontin$ing di"agreement on the mo"t a!!ro!riate o!eration #or di##erentiated

thyroid 'ar'inoma. The 'on"eratie a!!roa'h ado'ate" lobe'tomy )ithi"thm$"e'tomy in mo"t !atient" )ith total thyroide'tomy re"ered #or "!e'i#i'

indi'ation" &iC- tho"e )ith bilateral di"ea"e or 7$dged to be in a high,ri"5 'ategory(.

The more radi'al a!!roa'h ado'ate" ro$tine total thyroide'tomy o#ten a" a "taged

!ro'ed$re de!ending on the !athologi'al #inding" o# the initial lobe'tomy.

The 'a"e #or a !oli'y o# total thyroide'tomy i" theoreti'ally ba"ed on the !realen'e

o# m$lti#o'ality in !a!illary 'ar'inoma and on the #ea"ibility therea#ter o# $"ing

radioiodine "'anning to dete't meta"ta"e"- the thyroid haing been ablated &ig.

//./2(. Ho)eer- the 'lini'al "igni#i'an'e o# m$lti#o'ality i" lo) a" lo'al re'$rren'e i"

in#re>$ent a#ter $nilateral re"e'tion. In addition- in tho"e "ele'ted !atient" in )hom

"'anning may be indi'ated- the remaining thyroid ti""$e may be ablated "a#ely )ith a

!reliminary do"e o# radioiodine. Mo"t im!ortantly there i" no eiden'e that the long,

term re"$lt" o# ro$tine total thyroide'tomy a" a !oli'y are better than tho"e o# more

'on"eratie o!eration"- and there i" a "$b"tantial ri"5 o# !ermanent

hy!o!arathyroidi"m. +learly the ri"5 o# !arathyroid damage arie" a''ording to

e%!erti"e and the #re>$en'y )ith )hi'h the o!eration i" done b$t- een at the Mayo

+lini'- )here thyroid "$rgery i" #re>$ently and e%!ertly done- the rate o#

hy!o!arathyroidi"m i" "igni#i'ant &Hay(.

The large ma7ority o# !atient" )ith di##erentiated 'ar'inoma- !arti'$larly "in'e B2 !er

'ent #all into a gro$! )ith a 1 !er 'ent mortality rate- i" a!!ro!riately treated by

lobe'tomy )ith i"thm$"e'tomy on the a##e'ted "ide. 6t the "ame time 'lini'ally

obio$" node"- )hi'h may be !retra'heal- !aratra'heal or in the 7$g$lar 'hain- areremoed. I# the 7$g$lar node" are e%ten"iely inoled- a modi#ied ne'5 di""e'tion

)ith !re"eration o# the a''e""ory nere and "ternoma"toid m$"'le may be 'arried o$t

thro$gh e%ten"ion o# the thyroide'tomy in'i"ion. :ery o''a"ionally it may be

ne'e""ary to "a'ri#i'e the re'$rrent laryngeal nere i# it i" 'om!letely en'ir'led and-

on een more rare o''a"ion"- e%trathyroidal "!read may re>$ire re"e'tion o# !art o#

the tra'hea.

When there i" 'lini'ally obio$" bilateral di"ea"e at o!eration- bilateral re"e'tion i"

'learly indi'ated and bilateral re"e'tion may al"o be indi'ated in the #e) !atient"

'la""i#ied a" high ri"5- altho$gh the eiden'e at !re"ent #or im!roed !rogno"i" i"

rather )ea5. Retro"!e'tie analy"i" o# o$t'ome in ?2 !atient" )ith !a!illary'ar'inoma treated at the Mayo +lini' bet)een 0B/? and 0BF2 "ho)ed im!roed


24/28

"$rial in high,ri"5 !atient" $ndergoing bilateral re"e'tion- 'om!ared )ith lobe'tomy

alone- altho$gh the di##eren'e )a" not "tati"ti'ally "igni#i'ant &Hay(. There )a" no

adantage #or total 'om!ared )ith near,total thyroide'tomy in )hi'h 031 g o#

thyroid ti""$e i" !re"ered on the 'ontralateral "ide to !rote't the blood "$!!ly to one

or more !arathyroid gland".

S$rgi'al o!eration"I"thm$"e'tomy. S)elling" 'on#ined to the thyroid i"thm$"- in'l$ding "mall

di##erentiated 'ar'inoma"- may be a!!ro!riately remoed by re"e'tion o# the i"thm$"

alone. I"thm$"e'tomy i" al"o an e##e'tie method o# relieing tra'heal ob"tr$'tion and

obtaining ti""$e #or diagno"i" in ana!la"ti' 'ar'inoma and lym!homa.

Thyroid lobe'tomy. Total lobe'tomy on the, a##e'ted "ide together )ith

i"thm$"e'tomy i" the a!!ro!riate o!eration #or remoal o# a di"'rete thyroid ")elling

and #or mo"t !atient" )ith di##erentiated 'ar'inoma. The !ro'ed$re- i# !er#ormed

meti'$lo$"ly by an e%!erien'ed "$rgeon- i" a""o'iated )ith ery little ri"5 o#

!o"to!eratie 'om!li'ation" "$'h a" re'$rrent laryngeal nere in7$ry. The !arathyroid

gland" "ho$ld be "een and !re"ered in "it$ i# !o""ible altho$gh the inta't gland" on

the 'ontralateral "ide )ill en"$re normal #$n'tion- remoal o# the 'ontralateral lobemay o''a"ionally be ne'e""ary in the #$t$re. It i" $nne'e""ary to ligate the main tr$n5"

o# the in#erior thyroid arterie". In"tead- the indiid$al arterial bran'he" "$!!lying the

thyroid gland "ho$ld be ligated 'lo"e to the thyroid- !re"ering the !arathyroid blood

"$!!ly. The re'$rrent laryngeal nere i" 'are#$lly e%!o"ed thro$gho$t the di""e'tion.

It i" !arti'$larly $lnerable 'lo"e to )here it ang$late" !o"teriorly to enter the laryn%-

at )hi'h "ite it i" intimately related to the lateral thyroid ligament &ligament o# Aerry(.

Near,total thyroide'tomy. Thi" 'on"i"t" o# total thyroid lobe'tomy on the a##e'ted

"ide- )ith 'on"eration o# 031 g o# thyroid ti""$e on the 'ontralateral "ide- )hi'h

!re"ere" the blood "$!!ly to one or both !arathyroid".

Total thyroide'tomy. The te'hni>$e i" e""entially that o# bilateral lobe'tomy and- i#

meti'$lo$"- the ri"5 o# 'om!li'ation" i" ery lo) e%'e!t #or !ermanent

hy!o!arathyroidi"m. The ri"5 o# hy!o!arathyroidi"m i" ariable b$t may be

a!!re'iable een in e%!erien'ed hand".

6dditional mea"$re"

Thyro%ine. It i" "tandard !ra'ti'e to !re"'ribe thyro%ine in a do"e o# 2.032.1 mg

daily- to "$!!re"" endogeno$" TSH !rod$'tion- #or all !atient" a#ter o!eration #or

di##erentiated thyroid 'ar'inoma on the ba"i" that "ome t$mo$r" are TSH de!endent.

S$!!re""ion o# the TSH leel "ho$ld be 'on#irmed by mea"$rement. ail$re o#

"$!!re""ion to a leel o# P2.0 i.tJlitre may indi'ate an inade>$ate do"e o# thyro%ine or

more $"$ally that the !atient i" non'om!liant. Ho)eer- "$!!re""ie thyro%ine i"

!robably not o# al$e in #olli'$lar 'ar'inoma- and i" $nli5ely to be o# bene#it in lo),ri"5 !atient" treated by lobe'tomy.Thyroid hormone re!la'ement i" obio$"ly

ne'e""ary a#ter total thyroide'tomy and in the ma7ority o# !atient" a#ter near,total

thyroide'tomy- and i" $"$ally gien in the #orm o# thyro%ine. *atient" )ith !otential

or a't$al di"tant meta"ta"e" )ho may re>$ire re!eated radioiodine admini"tration #or

"'anning and thera!y "ho$ld be gien tri,iodothyronine &?23 2 mgJday( be'a$"e it

i" m$'h "horter a'ting- and on "to!!ing it- in'rea"ed TSH "e'retion and thyroid

aidity #or iodine re'oer >$i'5ly "o that radioiodine may be gien a#ter "eeral day".

The !atient i" thereby "!ared )ee5" o# deelo!ing thyroid in"$##i'ien'y a#ter "to!!ing

thyro%ine be#ore radioiodine may be gien.

Radioiodine. I# meta"ta"e" ta5e $! radioiodine they may be dete'ted by "'anning and

may be treated )ith large do"e" o# radioiodine. or e##e'tie "'anning- all thyroidti""$e m$"t hae been ablated by either "$rgery or !reliminary radioiodine and the


25/28

!atient m$"t be hy!othyroid to im!roe $!ta5e. The indi'ation" #or "'anning a#ter

o!eration" #or di##erentiated 'ar'inoma are di"!$ted- b$t it i" !robably only indi'ated

in !atient" )ith $nre"e'table lo'al re'$rren'e or meta"tati' di"ea"e- high,ri"5 !atient"-

and in tho"e )ith a ri"ing "er$m thyroglob$lin leel. In addition- i# meta"ta"e" ta5e $!

radioiodine they are li5ely to be "$!!re""ed a" e##e'tiely by treatment )ith thyro%ine

a" by radioiodine. +a"e" in )hi'h "$!!re""ion ha" #ailed and radioiodine ha" gien!ermanent 'ontrol a!!ear to be $n'ommon.

I# meta"ta"e" hae been treated- the "'an "ho$ld be re!eated at ann$al interal" and

#$rther thera!e$ti' do"e" o# radioiodine gien a" ne'e""ary. Solitary di"tant meta"ta"e"

may be treated by e%ternal radiothera!y.

Thyroglob$lin. The mea"$rement o# "er$m thyroglob$lin i" o# al$e in the #ollo),$!

and in the dete'tion o# meta"tati' di"ea"e in !atient" )ho hae $ndergone "$rgery #or

di##erentiated thyroid 'an'er. Thi" mea"$rement may obiate the need #or "erial

radioa'tie iodine "'anning b$t )hen a ri"e o''$r"- a "'an )ill be indi'ated to 'on#irm

and lo'ate the meta"tati' di"ea"e. Thyroglob$lin leel" are- ho)eer- only an ad7$n't

to 'are#$l 'lini'al !al!ation o# the ne'5 be'a$"e lo'al re'$rren'e dete'table 'lini'ally

may be !re"ent )ith a lo) thyroglob$lin.Undi##erentiated &ana !la"ti'( 'ar'inoma

Thi" o''$r" mainly in elderly )omen and i" m$'h le"" o#ten diagno"ed no) than in

the !a"t )hen many thyroid lym!homa" )ere mi"ta5enly 'la""i#ied hi"tologi'ally a"

ana!la"ti' 'ar'inoma". ;o'al in#iltration i" an early #eat$re o# the"e t$mo$r" )ith

"!read by lym!hati'" and by the blood"tream. They are e%tremely lethal t$mo$r" and

"$rial #or more than 031 year" a#ter !re"entation i" mo"t $n$"$al. In mo"t 'a"e"

death o''$r" )ithin month" rather than )ithin year". 6n attem!t at '$ratie re"e'tion

i" only 7$"ti#ied i# there i" no in#iltration thro$gh the thyroid 'a!"$le and no eiden'e

o# meta"ta"e". Many o# the"e aggre""ie le"ion" !re"ent in an adan'ed "tage )ith

tra'heal ob"tr$'tion and re>$ire $rgent tra'heal de'om!re""ion. The tra'hea may be

de'om!re""ed and ti""$e obtained #or hi"tology by i"thm$"e'tomy. Tra'heo"tomy i"

be"t aoided. Radiothera!y "ho$ld be gien in all 'a"e" and may !roide a )orth)hile

!eriod o# !alliation a" may 'ombination 'hemothera!y in'l$ding do%or$bi'in

&6driamy'in(L.

Med$llary 'ar'inoma

The"e are t$mo$r" o# the !ara#olli'$lar &+(,'ell" deried #rom the ne$ral 're"t and not

#rom the 'ell" o# the thyroid #olli'le a" are other !rimary thyroid 'ar'inoma". The

'ell" are not $nli5e tho"e o# a 'ar'inoid t$mo$r and there i" a 'hara'teri"ti' amyloid

"troma &ig. //./0(. High leel" o# "er$m 'al'itonin &Q2.2 ngJml( are !rod$'ed by

many med$llar t$mo$r". The"e leel" #all a#ter re"e'tion o# a t$mo$r and )ill ri"e

again i# the t$mo$r re'$r". Thi" i" a al$able t$mo$r mar5er in the #ollo),$! o#!atient" )ith thi" di"ea"e. 8iarrhoea i" a #eat$re in


26/28

Inolement o# lym!h node" o''$r" in 423?2 !er 'ent o# 'a"e" o# med$llary

'ar'inoma and blood,borne meta"ta"e" are 'ommon. 6" )o$ld be e%!e'ted- t$mo$r"

are not hormone de!endent and do not ta5e $! radioa'tie iodine. The 'o$r"e o# the

t$mo$r i" $n!redi'table in general- li#e e%!e'tan'y i" e%'ellent i# the t$mo$r i"

'on#ined to the thyroid gland- good a" long a" meta"ta"e" are 'on#ined to the 'eri'al

lym!h node" and !oor on'e blood,borne meta"ta"e" are !re"ent.Treatment i" by total thyroide'tomy and re"e'tion o# inoled lym!h node" )ith

either a radi'al or modi#ied radi'al ne'5 di""e'tion. amilial 'a"e" are no) dete'ted

by geneti' "'reening #or the RET on'ogene m$tation" )hi'h identi#ie" indiid$al"

)ho )ill deelo! med$llary 'an'er later in li#e &ig. //./


27/28

Aio'hemi'al te"t" o# thyroid #$n'tion ary )ith the thyroid "tat$" and are o#

diagno"ti' al$e only i# hy!othyroidi"m i" !re"ent. Signi#i'antly- rai"ed titre" o# one

or more thyroid antibodie" are !re"ent in oer 4 !er 'ent o# 'a"e". Neerthele""-

di##erential diagno"i" #rom nod$lar goitre- 'ar'inoma and malignant lym!homa o# the

thyroid i" not al)ay" ea"y. N6+ i" the mo"t a!!ro!riate ine"tigation altho$gh

ab$ndant lym!ho'yte" may ma5e the 'ytologi'al di"tin'tion bet)een a$toimm$nethyroiditi" and lym!homa di##i'$lt &ig. //./?(. When there i" do$bt abo$t neo!la"ti'

di"ea"e- )hi'h may 'oe%i"t )ith thyroiditi"- o!eration i" ne'e""ary.

Treatment

$ll re!la'ement do"age o# thyro%ine "ho$ld be gien #or hy!othyroidi"m and i# the

goitre i" large or "ym!tomati'- be'a$"e "ome &$nder TSH "tim$lation( may "$b"ide

)ith hormone thera!y. More minor mani#e"tation" o# the 'ondition "$'h a" a "mall

goitre )ith rai"ed antibody titre"- or hi"tologi'al eiden'e o# thyroiditi" in a""o'iation

)ith other thyroid di"ea"e- do not 7$"ti#y thyro%ine re!la'ement i# thyroid #$n'tion i"

bio'hemi'ally normal ho)eer- long,term "$reillan'e i" ne'e""ary be'a$"e o# the

ri"5 o# late thyroid #ail$re. O''a"ionally the goitre in'rea"e" in "!ite o# hormone

treatment and in the"e 'ir'$m"tan'e" there may be a #ao$rable re"!on"e to "teroidthera!y. Thyroide'tomy may be ne'e""ary i# the goitre i" large and 'a$"e" di"'om#ort.

The 'lini'ian m$"t- ho)eer- be 'a$tio$" )hen a lym!ho'yti' goitre in'rea"e" in "iCe

and be'ome" $nre"!on"ie to thyro%ine a" thi" may be d$e to the deelo!ment o#

malignant lym!homa.

Gran$lomato$" thyroiditi" &"$ba'$te thyroiditi" 3de $erain9" thyroiditi"(

Thi" i" d$e to a ir$" in#e'tion. &6n e!idemi' re!orted #rom I"rael )a" d$e to a

m$m!" ir$".( In a ty!i'al "$ba'$te !re"entation there i" !ain in the ne'5- #eer-

malai"e and a #irm- irreg$lar enlargement o# one or

both thyroid lobe". There i" a rai"ed erythro'yte "edimentation rate and ab"ent thyroid

antibodie"- the "er$m T/ i" high- normal or "lightly rai"ed- and the01< I $!ta5e o# the

gland i" lo) The 'ondition i" "el#,limiting and in a #e) month" the goitre ha"

"$b"ided "$b"e>$ent hy!othyroidi"m i" rare. In 02 !er 'ent o# 'a"e" the on"et i" a'$te-

the goitre ery !ain#$l and tender- and there may be "ym!tom" o# hy!erthyroidi"m.

Thirty,#ie !er 'ent o# 'a"e" are a"ym!tomati' b$t #or the !re"en'e o# the goitre. I#

diagno"i" i" in do$bt- it may be 'on#irmed by N6+- radioa'tie iodine $!ta5e and by

a ra!id "ym!tomati' re"!on"e to !redni"one. The "!e'i#i' treatment #or the a'$te 'a"e

)ith "eere !ain i" to gie !redni"one 02312 mg daily #or F day" and the do"e i" then

grad$ally red$'ed oer the ne%t month.

Riedel9" thyroiditi"

Thi" i" ery rare- a''o$nting #or 2.4!er 'ent o# goitre". Thyroid ti""$e i" re!la'ed by

'ell$lar #ibro$" ti""$e )hi'h in#iltrate" thro$gh the 'a!"$le into ad7a'ent m$"'le"-!aratra'heal 'onne'tie ti""$e and the 'arotid "heath". It may o''$r in a""o'iation

)ith retro!eritoneal and media"tinal #ibro"i" and i" mo"t !robably a 'ollagen di"ea"e.

The goitre may be $nilateral or bilateral and i" ery hard and #i%ed. The di##erential

diagno"i" #rom ana!la"ti' 'ar'inoma 'an only be made )ith 'ertainty by bio!"y- )hen

a )edge o# the i"thm$" "ho$ld al"o be remoed to #ree the tra'hea. I# $nilateral- the

other lobe i" $"$ally inoled later and "$b"e>$ent hy!othyroidi"m i" 'ommon.

$rther reading

+ohn- K.H.- Aa'5dahl- M.- or""l$nd- +. et al. &0B/( Aiologi' 'on"ideration" and

o!eratie "trategy in !a!illary thyroid 'an'er@ arg$ment" again"t the ro$tine!er#orman'e o# total thyroide'tomy. S$rgery- B?-


28/28

B4F3F2.

+$"i'5- E.;.- Kr$5o)"5i- Z.H. and Mathe"on- N.6. &0BF( O$t'ome o# "$rgery #or

Grae"9 di"ea"e rei"ited. Ariti"h o$rnal o# S$rgery- F/- F23

Documents

44.the Thyroid Gland and the Thyroglossal Tract