Parapharyngeal Space NeoplasmsParapharyngeal Space Neoplasms

Grand Rounds PresentationGrand Rounds Presentation

February 18, 1998February 18, 1998

Kyle Kennedy, M.D.Kyle Kennedy, M.D.

Anna Pou, M.D.Anna Pou, M.D.

IntroductionIntroduction

AnatomyAnatomy PPS NeoplasmsPPS Neoplasms Presentation and EvaluationPresentation and Evaluation Surgical ApproachesSurgical Approaches ComplicationsComplications

Introduction Introduction

PPS neoplasms account for approx. 0.5% of PPS neoplasms account for approx. 0.5% of head and neck tumorshead and neck tumors

PPS anatomy is complex with many PPS anatomy is complex with many important neurovascular structuresimportant neurovascular structures

most PPS neoplasms are benign most PPS neoplasms are benign surgical resection mainstay of therapysurgical resection mainstay of therapy systematic preoperative evaluation essential systematic preoperative evaluation essential

for proper treatment planningfor proper treatment planning

AnatomyAnatomy

potential space lateral to upper pharynxpotential space lateral to upper pharynx inverted pyramid shapeinverted pyramid shape fascial compartmentalizationfascial compartmentalization

AnatomyAnatomy superior-small portion of temporal bonesuperior-small portion of temporal bone inferior-junction of post. belly of digastric inferior-junction of post. belly of digastric

m. and greater cornu of hyoid bonem. and greater cornu of hyoid bone posterior-fascia overlying vertebral column posterior-fascia overlying vertebral column

and paravertebral mm.and paravertebral mm. medial-pharyngobasilar fascia/superior medial-pharyngobasilar fascia/superior

pharyngeal constrictor m. complexpharyngeal constrictor m. complex lateral-med. pterygoid fascia, mandibular lateral-med. pterygoid fascia, mandibular

ramus, retromandibular parotid, post. belly ramus, retromandibular parotid, post. belly digastric m.digastric m.

AnatomyAnatomy fascial compartmentalizationfascial compartmentalization fascia from tenson veli palatini to styloid process fascia from tenson veli palatini to styloid process

and its muscle complexand its muscle complex prestyloid region-deep lobe of parotid, fat, and prestyloid region-deep lobe of parotid, fat, and

lymph nodeslymph nodes poststyloid region-internal carotid a., internal poststyloid region-internal carotid a., internal

jugular v., CNs IX-XII, sympathetic chain, and jugular v., CNs IX-XII, sympathetic chain, and lymph nodeslymph nodes

stylomandibular ligament and tunnelstylomandibular ligament and tunnel

PPS NeoplasmsPPS Neoplasms

primary neoplasms-approx. 80% benign and primary neoplasms-approx. 80% benign and 20% malignant20% malignant

approx. 50% from deep lobe of parotid or approx. 50% from deep lobe of parotid or minor salivary gland tissue and 20% of minor salivary gland tissue and 20% of neurogenic originneurogenic origin

Salivary Gland NeoplasmsSalivary Gland Neoplasms

majority are benign pleomorphic adenomasmajority are benign pleomorphic adenomas intraparotid origin-retromandibular portion intraparotid origin-retromandibular portion

of gland, deep lobe, or tail of glandof gland, deep lobe, or tail of gland extraparotid origin-ectopic rests of salivary extraparotid origin-ectopic rests of salivary

gland tissuegland tissue

Neurogenic NeoplasmsNeurogenic Neoplasms most common-neurilemmoma or scwhannoma most common-neurilemmoma or scwhannoma

arising from vagus n. or sympathetic chain arising from vagus n. or sympathetic chain (usu. do not affect n. of origin)(usu. do not affect n. of origin)

paraganglioma or chemodectoma from vagal paraganglioma or chemodectoma from vagal or carotid bodies (approx. 10% malignant and or carotid bodies (approx. 10% malignant and 10-20% multicentric)10-20% multicentric)

neurofibroma (typically multiple and neurofibroma (typically multiple and intimately asso. with n. of origin)intimately asso. with n. of origin)

Presentation and EvaluationPresentation and Evaluation

signs and symptoms often subtle until signs and symptoms often subtle until tumor has substantially enlargedtumor has substantially enlarged

asymptomatic mass, lump in throat, fullness asymptomatic mass, lump in throat, fullness of neck and/or pharynx, cranial n. deficitsof neck and/or pharynx, cranial n. deficits

delay in diagnosis not uncommondelay in diagnosis not uncommon detailed Hx with complete head and neck detailed Hx with complete head and neck

examexam

Presentation and EvaluationPresentation and Evaluation

radiographic imaging (CT, MRI, radiographic imaging (CT, MRI, angiography)angiography)

assessment of catecholamine productionassessment of catecholamine production embolizationembolization fine needle aspiration bxfine needle aspiration bx

Surgical ApproachesSurgical Approaches

external most commonexternal most common adequate exposure for complete tumor adequate exposure for complete tumor

removalremoval identification, preservation, and control of identification, preservation, and control of

vital neurovascular structuresvital neurovascular structures minimize morbidity and mortalityminimize morbidity and mortality approach design should allow for extension approach design should allow for extension

to provide additional exposure as necessaryto provide additional exposure as necessary

Surgical ApproachesSurgical Approaches

cervical or cervical-parotidcervical or cervical-parotid cervical or cervical-parotid with midline cervical or cervical-parotid with midline

mandibulotomymandibulotomy cervical approach adequate for removal of cervical approach adequate for removal of

majority of tumorsmajority of tumors

ComplicationsComplications

neurovascular injuryneurovascular injury mandibulotomy complicationsmandibulotomy complications tumor recurrencetumor recurrence other complicationsother complications

ConclusionsConclusions PPS is complex anatomical region containing PPS is complex anatomical region containing

many vital structuresmany vital structures majority of PPS neoplasms are salivary or majority of PPS neoplasms are salivary or

neurogenic tumorsneurogenic tumors surgical resection treatment of choicesurgical resection treatment of choice careful preoperative planning essentialcareful preoperative planning essential cervical approach adequate for majority of tumorscervical approach adequate for majority of tumors flexible approach with minimal M&Mflexible approach with minimal M&M