Powerpoint : disorders-of-the-thyroid-gland-ii

HYPERTHYROIDISM

Increased serum levels of thyroid hormones,

Surgical correction is frequently appropriate

HYPERTHYROIDISM

Common causes:- diffuse toxic goitre (Graves’s disease),- toxic multinodular goitre (Plummer’s disease),- toxic solitary nodule,- exogenous thyroid hormone excess,- thyroiditis

HYPERTHYROIDISM

Rare causes: - metastatic thyroid carcinoma, - pituitary tumour secreting TSH

GRAVES’S DISEASE

The most common cause of hyperthyroidismIt is an immunological disordersThyroid stimulating antibodies (Ig G type)

bind to the TSH receptor of the thyroid cells- excess of the thyroid hormones

The thyroid gland hypertrophiesDiffuse enlargement

GRAVES’ DISEASEClinical Diagnosis

Symptoms and signs of thyrotoxicosis result from excess thyroid hormones:Cardio vascular Neurological Metabolic ExophtalmosDiffuse enlargement of the thyroid

GRAVES’ DISEASE

Ophthalmopathy- two major components:-Non-infiltrating ophthalmopathy

-sympathetic activity - upper lid retraction, - a stare, - infrequent blinking

-Infiltrating ophthalmopathy- edema of the orbital contents, lids, periorbital tissue, cellular infiltration within the orbit

Surgical specimen

Recurrent Grave’s disease after subtotal thyroidectomy, nodule at the piramidal lobe

Right thyroid nodules after subtotal thyroidectomy

Nodules with cystic degeneration after subtotal thyroidectomy

Left upper nodule with cystic degeneration

GRAVES’ DISEASEINVESTIGATIONSLaryngoscopy- mobility of vocal cordsCXR, ECGMeasurement of free T3, T4, TSHIsotope scanning not essential but necessary

in the assessment of toxic solitary and multinodular goitre- the site of nodular overactivity

Radioactive iodine uptake- increased uptake in the thyroid gland

GRAVES’ DISEASETREATMENT

To restore the euthyroid state:Antithyroid drugs+ beta-blockersRadioactive iodine- distroys overactive tissueSurgery- bilateral subtotal/total thyroidectomy

Grave’s diseaseMultiple nodules and hypervascularity

Grave’s diseasePressure symptoms

TOXIC MULTINODULAR GOITRETREATMENT

ATD- waste of timeRadioactive iodine- not indicatedSurgery- total thyroidectomy appropriate

TOXIC SOLITARY NODULETREATMENT

This condition is caused by a single autonomous thyroid nodule

Best option- Surgery- unilateral thyroid lobectomy

Thyroid scintigramAutonomous adenoma in

the right lobe of the struma.

The test substance accumulates almost exclusively in the range of the autonomous adenoma. The other areas of the struma show a considerable reduced accumulation of activity.

Toxic compressive goiter

Toxic nodular goiter

Thyroid USS: LTL-vol. 86,98 ml., RTL- vol. 5,54 ml. TSH=0,1 mcg/ml (0,4-7)

CT- expansive solid nodule LTLENT exam.- laryngoscopy- left recurent nerve

palsyAP- nodular goiter with cystic degeneration

and areas of hyperfunction

HYPERTHYROIDYPREOPERATIVE PREPARATION

Surgery must be done in the euthyroid state ATD for a period then discontinueBetablockers to control cardiac symptomsLugol’s solution,10 days, will diminish the

peroperative hemorrhagic risk

POSTOPERATIVE COMPLICATIONS

1. Postoperative bleeding2. Postoperative thyrotoxic crisis3.Postoperative voice changes4. Hypoparathyroidism5. Hypothyroidism

POSTOPERATIVE BLEEDINGPostoperative bleeding

there is always a risk of postop.bleeding,it is rare but sometimes dramatic

The bleeding may occur in one of two sites,- deep to the myofascial layer in relation to

thyroid vessels-evacuation must be done quickly

- deep to the skin flaps, from veinsCompressive hematoma- respiratory

embarrasment- evacuation is mandatory

POSTOPERATIVETHYROTOXIC CRISIS

Serious complication-where there has not been adequate preop.preparation

It occurs within the first 24 hours of thyroidectomy

Symptoms: confusion, hyperactive, fever, profuse sweating, rapid PR.

Treatment: beta-blockers, iv steroids, iodine

POSTOPERATIVE VOICE CHANGESRare due to any damage to recurrent laryngeal

nerves- this occurs in less than 1%Probably minor changes in the muscles around

the cricoid and thyroid cartilages are the most important, inevitable with the mobilization of the gland

Trauma to external laryngeal nerve- cricothyroid muscle- voice change- difficulty in achieving vocal cord tension

Trauma t the internal laryngeal nerve can occur where there is difficulty in mobilizing the superior pole

POSTOPERATIVE HYPOPARATHYROIDISMHypocalcemia- usually a consequance of a

metabolic changes- re-entry of calcium into bone demineralized by hyperthyroidism (“hungry bones”)

Parathyroids are small and are not always easy to identify

The incidence of hypoparathroidism after surgery shoud be less than 1%

Hipoparathyroidism and hypocalcemiaTransient or definitive- 1%-15%Manipulation of the PT glands- neck

dissectionSingle vs. 3 glands preserved for normal PT

fct.Non-capsular dissection technique- risk of

injuryIncidental removal with thyroid gland PT- reimplant into the SCM muscleIdentification of PT- avoid injury risk

Hypoparathyroidism

THYROID CANCERTumors of thyroid follicular epithelium

Papillary carcinomaFollicular carcinomaAnaplastic carcinoma

Tumors of parafollicular cellsMedullary carcinoma

Tumors of lymphoid cellsLymphoma

PAPILLARY CARCINOMAThe commonest thyroid tumorPrevious neck irradiation-risk factor-thy.ca.Hard whitish noduleLymphatic spreadThree types based on tu. size and extent:

Minimal lesion<1cmIntrathyroid lesion>1cm.within the thyroidExtrathyroid lesion-locally advanced

FOLLICULAR CARCINOMA

Encapsulated, solitary noduleUsually firm, but soft when intratumor hg.Spread via the boodstreamTwo main types after histopathology:

Minimally invasive-slight capsular or vascular invasion

Frankly invasive-venous extension into thyroid and jugular veins

The TNM stages of thyroid cancer

“TNM” stands for Tumour, Node, Metastasis. T1 - the tumour is entirely inside the thyroid and is less

than 2cm across in any direction T2 - The tumour is entirely inside the thyroid and is more

than 2cm but no more than 4cm across in any direction T3 - The tumour is entirely inside the thyroid and is more

than 4cm across in any direction T4a - The cancer has grown outside the thyroid gland into

the surrounding tissue. T4b - The cancer has grown outside the thyroid gland into

the area surrounding the bones of the spine, or one of the main blood vessels nearby.

TNM stagingN0- no lymph nodes contain cancer cellsN1a - there are lymph nodes containing cancer cells on one

side of the neck only (on the same side as the cancer) N1b - there are lymph nodes containing cancer cells

anywhere else (usually the other side of the neck or in the chest)

M0- no distant MTSM1 - present distant MTS

TNM stagingDifferentiated thyroid cancer: papillary and folicular thyroid cancerUnder 45years of age:Stage 1 - cancer is only inside the thyroid, or

the thyroid and the lymph glands

Stage 2 - cancer has spread presenting metastases

TNM staging for differentiated thyroid cancer, over 45 years of age

Stage 1 - cancer is only inside the thyroid and is less than 2cm across

Stage 2 - cancer is any size, but is only inside the thyroid

Stage 3 - cancer has grown beyond the thyroid capsule, or there are cancer cells in the lymph nodes

Stage 4 - cancer has spread to other parts of the body, such as lungs or bones

TREATMENT OF DIFFERENTIATED THYROID CANCER

Thyroidectomy is the treatment of choiceObjectives- to eradicate primary tumor - to reduce the incidence of recurrencePapillary cancer-multifocality-total

thyroidectomy is the best option plus clearance of cervical lymph nodes

Follicular cancer- if minimal-lobectomy - If invasive-total thyroidectomy

POSTOPERATIVE TREATMENTThyroxine after total thyroidectomyThyroglobuline measurement-sensitive

indicator of residual or recurrent differentiated thyroid cancer after total thyroidectomy

Radioactive iodine is a useful means of detecting metastatic disease after total thyroidectomy

ANAPLASTIC CARCINOMAHighly aggressive tumor, affects the

elderlyRapidly infiltrates local structuresMetastases via bloodstream, lymphaticsLong history of goitre that suddenly starts

to grow rapidlyVoice change, dysphagia, dyspneaResection is rarely possibleSurvival within six months

Staging for anaplastic thyroid cancerThere is no number staging system for

anaplastic thyroid cancer. This is because there is a high risk of the

cancer spreading. If the cancer is only in the neck - complete

removal If the patient is fit enough - surgery or

radiotherapy

MEDULLARY CARCINOMAIncidence-8% of thyroid malignanciesSolid non-follicular carcinomaArises from the parafollicular cells, C-cells

which secretes calcitonin- hypocalcemiaIn the upper 2/3rds, multicentric, bilateralSpreads by lymphatics to regional nodesSpreads via bloodstream to liver, lungs,

bones

MEDULLARY CARCINOMAThis tumor produces calcitonin- tu.markerCEA- another tu.markerThis tu. can secrete a range of hormones and

peptides: prostaglandins, 5-hydroxitryptamine, ACTH.

Diagnosis- FNAC, serum calcitoninAssociation with pheochromocytoma- urinary

VAM and metanephrines

MEDULLARY CARCINOMATREATMENT Total thyroidectomy is the best optionCentral and paratracheal lymph nodes

clearance,Carotid sheath nodes removed, if involved

with tu.- modified radical neck dissection, preserving IJV, SCM, spinal accessory nerve.

Bilateral lymph nodes clearance is advised

Medullary thyroid cancer

There are 4 number stages for medullary thyroid cancer. These are:

Stage 1 - cancer is less than 2cm across Stage 2 - cancer is between 2cm and 4cm

across Stage 3 - There is spread to cervical lymph

nodes Stage 4 - The cancer cells have spread to

another part of the body  

MEDULLARY CARCINOMAFOLLOW-UP

Follow-up: calcitonin, CEAIf raised- persistent or recurrent diseaseUltrasonography, CT, MRI,scintigraphyExternal irradiation- last chanceChemotherapy is disapointingPresent lymph nodes metastases-survival rate

is 45% at 10 years

THYROIDITIS

Subacute thyroiditisAutoimmune thyroiditisRiedel’s thyroiditisAcute suppurative thyroiditis

SUBACUTE THYROIDITISGranulomatous or de Quervain’s thyroiditisProbably viral originPainful swelling of one or both thyroid

lobes, malaise, feverPreceding history of sore throat or viral

infection a week or two before the onset of thyroid symptoms

Symptoms and signs of hyperthyroidismThyroid hormone levels raised but low

uptake of radioactive iodine, ESR is raised

SUBACUTE THYROIDITIS

The disease process is self-limiting with resolution of local sy. and thy. dysfunction

Few pts. pass through a mild hypothyroid phase

Local sy.-aspirin, steroidsTransient hyperthyroidism does not require

antithyroid drugs

AUTOIMMUNE THYROIDITIS

Diffuse process throughout the thyroid gland- Hashimoto’s disease

Infiltration of thyroid by lymphocytes and plasma cells

Immunological disorder- serum thyroid ab.Hypothyroidism- thyroxine, steroidsNodule present- FNAC to rule out lymphoma

RIEDEL’S THYROIDITIS

Invasive fibrous thyroiditis- dense fibrous inflammatory infiltrate throughout the thyroid extended extracapsular

Rare condition, can mimic malignancyTamoxifen, or surgery for pressure sy.

ACUTE SUPPURATIVE THYROIDITIS

The thyroid can be infected by bacterial or fungal agents

Acute painfully inflammed glandNeedle aspiration- dg. & bacteriologyAppropriate antibiotics

PRIMARY HYPERPARATHYROIDISMSymptoms: renal lithiasis, osteitis fibrosa

cystica, peptic ulcer, cholelithiasis, weakness, constipation

Lab. tests: elevated serum calcium, serum PH high, decreased serum phosphorus, hyperphosphaturia

Radiology: skull XR- ground-glass appearance

Localization: USS, CT, MRISurgery- removal of adenoma

DISORDERS OF THE PARATHYROID GLANDPTH- regulator of calcium metabolismActs in conjunction with calcitoninSerum Ca falls- PTH increasesSerum Ca rises- PTH decreasesIncreased PTH secretion:

HypercalcemiaHypocalciuriaHypophosphatemiahyperphosphaturia

PRIMARY HYPERPARATHYROIDISMMay occur as:

- part of a multiple endocrine adenomatosis syndrome,

- familial hyperparathyroidism, - ectopic tumor90% due to a solitary adenoma10% due to four-gland hyperplasia1%- due to parathyroid carcinoma

Osteita fibrosa cystica- parathyroid adenoma

Left parathyroid adenoma

Left parathyroid adenoma

Right parathyroid adenoma

Right parathyroid adenoma

Parathyroid adenoma

Surgical specimen

What is abnormal at this face??

Myasthenia gravis

Motor end-plate in MG

Which organ is involved in the patholopgy of MG??

Where the thymus is located??

Pneumomediastinography

A.Gh. 65 years old, 3 w. of severe myasthenia, Oss.IIICT-calcified thymoma adherent to the left mediastinal pleura, op. 2003, histology- type A, medullary thymoma without capsular invasion, chemotherapy CP+PDN, obvious improvement

CT, 60 years old, thymoma+MG, Oss.IV, op. 2002, Lymphocitic thymoma (type I malignant thymoma)-Masaoka II ( well encapsulated but microscopic capsular invasion), adhesions to left M. pleura which was resected

Radiotherapy 44 Gy, chemotherapy, 1 year CP+PDNPericarditis and mixedema at 1 year postRxTRemission of MG for 5 years, 2008- AChE

Different approaches to the thymus

Position of the patient for thymectomy

Sterile field

Median complete sternotomy

Dissection

Intradermic suture

OP.IAN.2009

Longitudinal incision

Sternotomy

Sternal retracter

Dissection

Dissection

Dissection

Dissection

Dissection

Dissection

Left innominate vein

Mediastinal aspect after tumor resection+pleurectomy

Sternoraphy- 3 metalic wires

Specimen

CT-2009

Presternal fascial closure

Skin sutured

Right eye ptosis