6Our Subject:What to operate?When to operate?How to operate?
7Surgery Goals (general) An organ has a malfunction that cannot be treated madicallyAn organ is getting huge sizes and the pressure effects cannot be treated medicallyAn organ harbors a mass/tumor that must be excisedThere is a mal-placed or developmental anomaly that needs to be excised
9Thyroglossal Duct Cyst and Sinus The most commonly encountered congenital cervical anomaliesAnywhere along the migratory path of the thyroid80% in juxtaposition to the hyoid
10Thyroglossal Duct Cyst and Sinus heterotopic thyroid tissue in 20%usually asymptomaticoccasionally infected by oral bacteria: thyroid duct sinus secondary drainage of the cystAccompanied by minor inflammation of surrounding skin
11Diagnosis of Thyroglossal Duct Cyst Clinically: usually by observing a 1- to 2-cm, smooth, well-defined midline neck mass that moves upward with protrusion of the tongue.Routine thyroid imaging not necessaryThyroid scintigraphy and ultrasound: document the presence of normal thyroid tissue in the neck.
12Surgery of Thyroglossal Duct Cyst and sinus "Sistrunk operation“en bloc cystectomy and excision of the central hyoid bone to minimize recurrence.
13!!! of Thyroglossal Duct Cyst and sinus 1% contain cancer, 85% papillarySquamous, Hürthle cell, and anaplastic cancers also reported but rare.Medullary thyroid cancers (MTCs) are not found in thyroglossal duct cysts.Role of total thyroidectomy controversialSurgery advised in older patients with large tumors, particularly if with additional thyroid nodules and evidence of cyst wall invasion or lymph node metastases.
14Lingual Thyroid Failure of median thyroid anlage to descend normally May the only thyroid tissue present
15Treatment in Lingual Thyroid Necessary only if :1) Obstructive symptoms:chokingdysphagiaairway obstructionhemorrhage2) Hypothyroidism ( frequent)Medical treatment :exogenous thyroid hormone orRAI ablation followed by hormone replacement
16Surgery in Lingual Thyroid Surgical excision rarely neededIf required, should be preceded by evaluation of normal thyroid tissue in the neck to avoid inadvertently rendering the patient hypothyroid
17Ectopic Thyroid Found anywhere in the central neck compartment esophagustracheaanterior mediastinumadjacent to the aortic archin the aortopulmonary windowwithin the upper pericardiumin the interventricular septumOften, "tongues" of thyroid tissue seen extending off the inferior poles particularly in large goiters
18!!! in Ectopic ThyroidWhen thyroid tissue lateral to carotid sheath and jugular vein (termed lateral aberrant thyroid): almost always metastatic thyroid cancer in lymph nodesEven if not apparent on exam or US, the ipsilateral thyroid lobe contains a focus of papillary thyroid cancer (PTC), which may be microscopic.
19Pyramidal LobeIn 50%, the distal end of the thyroglossal duct persists : a pyramidal lobe projecting up from the isthmus, just to the left or right of the midline.NL: not palpableIn thyroid hypertrophy : enlargedand palpable
20Surgery Goals (general) An organ has a malfunction that cannot be treated madicallyAn organ is getting huge sizes and the pressure effects cannot be treated medicallyAn organ harbors a mass/tumor that must be excisedThere is a mal-placed or developmental anomaly that needs to be excised
23Diffuse Toxic Goiter (Graves' Disease) Etiology of autoimmune process: not knownThyroid gland diffusely and smoothly enlarged
24Clinical Features of Graves Disease Divided intothose related to hyperthyroidismthose specific to Graves' disease
25Clinical Features ofhyperthyroidism in Graves Disease Hyperthyroid symptoms:heat intoleranceincreased sweatinghair lossweight loss despite adequate caloric intakepalpitationsnervousnessfatigueemotional labilitytremorsdiarrheawomen:amenorrheadecreased fertilitymiscarriageschildren:rapid growthearly bone maturationolder patients:AFCHF
26Clinical Features of Hyperthyroidism in Graves Disease On physical examination:weight lossfacial flushingwarm and moist skinafrican americans: darkening of skintachycardia or atrial fibrillationwidening of the pulse pressurefine tremormuscle wastingproximal muscle group weaknesshyperactive tendon reflexes
27Clinical Features Specific to Graves Disease 50% : ophthalmopathyspasm of the upper eyelid revealing the sclera above the corneoscleral limbus (Dalrymple's sign)prominent stare, due to catecholamine excesslid lag (von Graefe's sign)periorbital edemaconjunctival swelling and congestion (chemosis)keratitisproptosislimitation of upward and lateral gaze (from involvement of the inferior and medial rectus muscles, respectively)blindness due to optic nerve involvement
28Clinical Features Specific to Graves Disease 1-2%: dermopathy : deposition of glycosaminoglycans leading to thickened skin in pretibial region and dorsum of the footGynecomastia common in young menRare subperiosteal bone formation and swelling in metacarpals (thyroid acropachy)Onycholysis, or separation of fingernails from their beds
29Clinical Features of Graves Disease On physical examination:thyroid usually diffusely and symmetrically enlargedenlarged pyramidal lobemay bruit or thrill and loud venous hum in supraclavicular space
30Diagnostic Tests for Graves’ disease Suppressed TSHElevated /NL f T4 or T3 or f T3If eye signs present, other tests generally not needed.If no eye findings: RAIU scan necessaryConfirms diagnosis: elevated uptake and diffusely enlarged glandElevated Anti-Tg and anti-TPO in75%, non-specificElevated TSH-R or thyroid-stimulating Abs (TSAb):in 90% :diagnosticMRI of orbits: useful in evaluating ophthalmopathy.
31? ? ? May be treated by: antithyroid drugs TreatmentMay be treated by:antithyroid drugsthyroid ablation with radioactive 131Isurgery??
32Antithyroid DrugsGenerally used in preparation for RAI ablation or surgeryDrugs commonly used:propylthiouracil (PTU, 100 to 300 mg three times daily)methimazole (10 to 30 mg three times daily, then once daily)Methimazole has a longer half-life and can be dosed once daily
33RAI for Treatment of Graves’ Disease The mainstay of Graves' disease treatment in North America.Most often used in:older patients with small or moderate-sized goitersrelapse after medical or surgical therapyContraindication of antithyroid drugs or surgeryAbsolute contraindications to RAI:pregnant or breastfeeding womenRelative contraindications :young patients (i.e., especially children and adolescents)thyroid nodulesophthalmopathy
34RAI for Treatment of Graves’ Disease The major advantages:no surgeryreduced overall treatment costsease of treatmentAntithyroid drugs given until euthyroidOnly 50% euthyroid 6 months after treatmentThe remaining still hyperthyroid or already hypothyroidAfter 1 year, 2.5% develop hypothyroidism each yearThe higher the initial dose of 131I, the earlier the onset and the higher the incidence of hypothyroidism
35Surgical Treatment of Graves’ Disease Indications:(a) confirmed cancer or suspicious thyroid nodules(b) young people(c) pregnant or desire to conceive soon after treatment(d) severe reactions to antithyroid medications(e) large goiters causing compressive symptoms(f) reluctant to RAI therapyRelative indications:Moderate to severe Graves' ophthalmopathy particularly in smokersdesiring rapid control of hyperthyroidism with a chance of being euthyroid,poor compliance to antithyroid medications
36Type of Surgery in Graves’Disease total or near-total thyroidectomycancerrefuse RAI therapysevere ophthalmopathylife-threatening reactions to antithyroid medications (vasculitis, agranulocytosis, or liver failure)Subtotal thyroidectomy (leaving a 4- to 7-g remnant)all remaining patients
37Surgical Treatment of Graves’ Disease Antithyroid drugs given up to the day of surgery to be euthyroidGenerally Lugol's iodide solution beginning 7 to 10 days preoperatively (three drops twice daily) to reduce vascularity and risk of precipitating thyroid storm
39Toxic Multinodular Goiter Often a prior history of nontoxic multinodular goiterOver several years, enough thyroid nodules become autonomous to cause hyperthyroidism.Usually in older people
40Presentation in Toxic MNG Symptoms and signs of hyperthyroidism similar to Graves’, extrathyroidal manifestations absentPresentation of hyperthyroidism often insidiousMay hyperthyroidism only apparent when on low dose thyroid hormone suppression for goiterMay hyperthyroidism precipitated by iodide-containing drugs (jodbasedow hyperthyroidism):contrast mediaamiodarone
41Diagnostic Studies in Toxic MNG Blood tests are similar to Graves:Suppressed TSHElevated free T4 or T3RAIU increased: multiple nodules with increased uptake and suppression of the remaining gland
42Preferred treatment: Surgery Treatment of Toxic MNGPreferred treatment: SurgeryStandard procedure: Subtotal thyroidectomyRemnant size not crucial because these require thyroid suppression to prevent recurrence
43Treatment of Toxic MNGRAI reserved for :Elderly with very poor operative risks ifno airway compression from the goiterandthyroid cancer not a concern.Uptake is less than in Graves' disease: larger doses of RAI neededRAI-induced thyroiditis may cause swelling and acute airway compromise, and leaves the goiter intact, with the possibility of recurrent hyperthyroidism
45Toxic Adenoma RAIU: "hot" nodule with suppression of rest of thyroid Recent growth of a long-standing noduleHyperthyroidism from a single hyperfunctioning noduleSymptoms of hyperthyroidism, typically in younger patientsPhysical examination : solitary thyroid nodule without palpable thyroid tissue on contralateral side
46Treatment of Toxic Adenoma Smaller nodules:antithyroid medicationsRAISurgery (lobectomy and isthmectomy): preferred for:young patientslarger nodules
50Acute (Suppurative) Thyroiditis Thyroid : resistant to infectionOften preceded by upper respiratory tract infection or otitis mediaMore common in children70%: Streptococcus and anaerobes
51Presentation of Acute (Suppurative) Thyroiditis Severe neck pain radiating to the jaws or earfever and chillsOdynophagiaDysphoniaMay Complications :systemic sepsistracheal or esophageal rupturejugular vein thrombosislaryngeal chondritis or perichondritissympathetic trunk paralysis
52Diagnosis of Acute (Suppurative) Thyroiditis Leukocytosis on blood testsFNAB for Gram's stain, culture, and cytologyCT scans: delineate the extent of infectionA persistent pyriform sinus fistula should always be suspected in children with recurrent acute thyroiditis. A barium swallow demonstrates the anomalous tract with 80% sensitivity.
53Treatment of Acute (Suppurative) Thyroiditis Parenteral antibioticsDrainage of abscessesIf pyriform sinus fistulaeComplete resection of the sinus tract, including the area of the thyroid where the tract terminates, to prevent recurrence.
55Painful Subacute Thyroiditis Exact etiology unknown, may be viralMost commonly in 30- to 40-yr womenSudden or gradual onset of neck pain, may radiate toward mandible or earOften history of preceding upper respiratory tract infectionThyroid enlarged, exquisitely tender, and firm
56Presentation of Painful Subacute Thyroiditis Classically progresses through 4 stages:1- an initial hyperthyroid phase, due to release of thyroid hormone2- followed by a euthyroid phase3- hypothyroidism which occurs in 20 to 30%4- resolution and return to euthyroid state in >90%A few patients develop recurrent disease.
57Treatment of Painful SubacuteThyroiditis Primarily symptomatic.Aspirin and other NSAIDs for pain reliefSteroids may indicated in more severe casesShort-term thyroid replacement may neededThyroidectomy reserved for the rare patient who has a prolonged course not responsive to medical measures or for recurrent disease
58Painless Subacute Thyroiditis May be autoimmunemay occur:sporadicallyorin postpartum periodat about 6 weeks after delivery in women with high TPO antibody titers in early pregnancy
59Presentation of Painless Subacute Thyroiditis Usually yr woman.Physical examination : normal sized or minimally enlarged, slightly firm, nontender glandClinical course parallels painful thyroiditisIf symptomatic: may require beta blockers and thyroid hormone replacementThyroidectomy or RAI ablation only indicated for the rare patient with recurrent, disabling episodes of thyroiditis.
63Hashimoto‘s Thyroiditis The leading cause of hypothyroidismAutoimmune processMore common in yr women (male:female ratio 1:10 to 20 )
64Clinical Presentation of Hashimoto The most common presentation:mildly enlarged firm granular glandorpainless anterior neck mass20%: hypothyroidism5% : hyperthyroidism (Hashitoxicosis)physical examination: diffusely enlarged, firm , lobulated glandenlarged pyramidal lobe often palpable
65Diagnosis of Hashimoto's Elevated TSHandThyroid autoantibodiesusually confirm the diagnosisFNAB if:solitary suspicious noduleorrapidly enlarging goiter
66A complication of Hashimoto: Thyroid lymphoma Rare !!! of Hashimoto'sA complication of Hashimoto: Thyroid lymphomaRarePrevalence 80 times higher than control population
67Treatment of Hashimoto In overtly hypothyroid patients:thyroid hormone replacement, with a goal of maintaining normal TSH levelsSurgery occasionally indicated for:suspicion of malignancygoiters causing compressive symptomscosmetic deformity
69Riedel's thyroiditis = Riedel's struma or invasive fibrous thyroiditis Rare= Riedel's struma or invasive fibrous thyroiditisReplacement of all or part of the thyroid parenchyma by fibrous tissue, also invades into adjacent tissuesEtiology controversial, may be autoimmuneAssociated with other focal sclerosing syndromes: mediastinal, retroperitoneal, periorbital, retro-orbital fibrosis and sclerosing cholangitis
70Presentation in Riedel's Thyroiditis In yrPainless hard anterior neck mass, which progresses over weeks to yearsSymptoms of compression:dysphagiadyspneachokinghoarsenessMay symptoms of hypothyroidism and hypopara as the gland is replaced by fibrous tissue
71Diagnosis in Riedel's Thyroiditis Hard, "woody" thyroid gland with fixation to surrounding tissuesDiagnosis needs to be confirmed by open thyroid biopsy, because the firm and fibrous nature of the gland renders FNAB inadequate
72Treatment in Riedel's thyroiditis Mainstay of treatment: surgeryChief goal of operation: decompression of trachea by wedge excision of thyroid isthmus and make a tissue diagnosisMore extensive resections not advised due to infiltrative nature of fibrotic processIf hypothyroid: treated with thyroid hormone replacement
73Surgery Goals (general) An organ has a malfunction that cannot be treated madicallyAn organ is getting huge sizes and the pressure effects cannot be treated medicallyAn organ harbors a mass/tumor that must be excisedThere is a mal-placed or developmental anomaly that needs to be excised
75Any enlargement of thyroid gland is referred to as a goiter May bediffuseuninodularmultinodular
76Goiter - Clinical Features(1) Mostly asymptomaticBut often pressure sensation in neckHaving to clear their throats frequently (catarrh).As the goiters become very large: compressive symptoms such as dyspnea and dysphagiaDysphonia from RLN injury rare, except if cancerous
77Goiter - Clinical Features(2) Obstruction of venous return at the thoracic inlet from a substernal goiter results in a positive Pemberton's sign—facial flushing and dilatation of cervical veins upon raising the arms above the headSudden enlargement of nodules or cysts due to hemorrhage may cause acute pain.Physical examination may reveal a soft, diffusely enlarged gland (simple goiter) or nodules of various size and consistency in case of a multinodular goiter.Deviation or compression of the trachea may be apparent
78Goiter -Diagnostic Tests Usually euthyroid: normal TSH and low-normal or normal f T4If some nodules develop autonomy: suppressed TSH or hyperthyroidRAI scan: often patchy uptake with areas of hot and cold nodulesFNAB recommended in dominant nodule or one that is painful or enlarging!!! Carcinomas reported in 5 to 10% multinodular goitersCT scans: evaluate extent of retrosternal extension and airway compression
79Treatment of Goiter Euthyroids with small diffuse goiters: no treatmentEuthyroids with large goiters:exogenous hormone to reduce TSHEndemic goiters :iodine administration
80Surgical Treatment of Goiter Surgical resection for goiters that:continue to increase despite T4 suppressioncause obstructive symptomshave substernal extensionhave malignancy suspected or proven by FNABare cosmetically unacceptableSubtotal thyroidectomy is the treatment of choicePatients require lifelong T4 therapy to prevent recurrence.
82Solitary Thyroid Nodule Present in approximately 4% of people in USABut thyroid cancer has a much lower incidence (40 new cases per 1 million)Therefore, it is of utmost importance to determine which patients with solitary thyroid nodule would benefit from surgery.
83Approach to Solitary Thyroid Nodule History :Exposure to ionizing radiationFamily history of thyroid and other malignancies associated with thyroid cancer.DysphagiaDyspneaChokingHoarseness:may malignant involvement of the RLNsAsk about:Time of onsetChange in sizePain: unusual, raise suspicion forIntrathyroidal hemorrhage in a benign noduleThyroiditisMalignancy
84Physical Examination in STN Best palpated from behind patient with neck in mild extensionThe cricoid cartilage is an important landmark, as the isthmus is situated just below itNodules that are hard, or fixed to surrounding structures such as the trachea or strap muscles are more likely to be malignantThe cervical chain of lymph nodes should be assessed as well as the nodes in the posterior triangle
85Diagnostic Approach in STN FNAB has become the single most important test in the evaluation of thyroid massesCan be performed with or without ultrasound guidanceUltrasound guidance recommended for:nodules difficult to palpatecystic or solid-cystic nodules that recur after aspiration
86FNA in STNA 23-gauge needle is inserted into the thyroid mass, and several passes are made while aspirating the syringe.After releasing the suction on the syringe, the needle is withdrawn and the cells are immediately placed on prelabeled dry glass slides.Some are immersed in a 70% alcohol solution and others are air dried.
87FNA of STNIf a bloody aspirate is obtained, the patient should be repositioned in a more upright position and the biopsy repeated with a finer (25- to 30-gauge) needle
88After FNAB FNA of STN benign (65%) suspicious (20%) malignant (5%) cysts and colloid nodules, risk of malignancy <3%suspicious (20%)Risk of malignancy 20%.malignant (5%)nondiagnostic (10%)
89False-positive: 1% False-negative: 3% FNA of STN FNAB less reliable in history of head and neck RT or FH of thyroid cancer, due to higher likelihood of multifocal lesions and occult cancerIf hyperthyroid, risk of malignancy 1%False-positive: 1%False-negative: 3%
91differentiating solid from cystic nodules identifying adjacent LAP Imaging in STNUS helpful fornonpalpable nodulesdifferentiating solid from cystic nodulesidentifying adjacent LAPfollowing the size of benign nodules diagnosed by US
92When not malignant or suspicious, lobectomy if : Surgery of STNWhen not malignant or suspicious, lobectomy if :cyst persists after three aspirationscysts >4 cmcomplex cysts with solid and cystic componentsnodule enlarges on TSH suppressioncompressive symptomscosmetic reasons
93Surgery of STN Exception :total or near-total thyroidectomy if previous thyroid RTfamily history of thyroid cancerbecause high incidence of cancerand decreased reliability of FNAB
94Surgery Goals (general) An organ has a malfunction that cannot be treated madicallyAn organ is getting huge sizes and the pressure effects cannot be treated medicallyAn organ harbors a mass/tumor that must be excisedThere is a mal-placed or developmental anomaly that needs to be excised
98Staging -1 Primary tumor (T) TX = Primary tumor cannot be assessed T0 = No evidence of primary tumorT1 = Tumor ≤2 cm in diameter, limited to thyroidT2 = Tumor >2 cm but <4 cm in diameter, limited to thyroidT3 = Tumor >4 cm in diameter, limited to thyroid, or any tumor with minimal extrathyroidal invasionT4a = Any size tumor extending beyond capsule to invade subcutaneous soft tissue, larynx, trachea, esophagus, or recurrent laryngeal nerve, or intrathyroidal anaplastic cancerT4b = Tumor invading prevertebral fascia, or encasing carotid artery or mediastinal vessels; or extrathyroidal anaplastic cancer
99Staging - 2 Regional lymph nodes (N) : NX = cannot be assessed N0 = No LN metastasisN1 = Regional LN metastasisN1a = Metastases to level VI (pretracheal, paratracheal, and prelaryngeal/Delphian lymph nodes)N1b = Metastases to unilateral, bilateral, or contralateral cervical or superior mediastinal lymph nodes
100Distant metastasis (M) MX = Distant metastases cannot be assessed Staging - 3Distant metastasis (M)MX = Distant metastases cannot be assessedM1 = No distant metastasis
102Papillary Tyroid Carcinoma 80% of all thyroid cancersThe predominant thyroid cancer in children and individuals exposed to external radiation2:1 female-to-male ratioMean age at presentation: 30 to 40 yr
103Presentation of Papillary Tyroid Carcinoma Mostly euthyroidSlow-growing painless mass in neckWith locally advanced invasive disease:dysphagiadyspneadysphonia
104Spread of Papillary Tyroid Carcinoma Lymph node metastases common, especially in children and youngDistant metastases uncommon initially, but may ultimately develop in 20%The most common metastatic sites:LungsBoneLiverBrain
105Diagnosis and Prognosis of PTC Diagnosis by FNAB of thyroid mass or lymph nodeOnce diagnosed on FNAB, neck US for evaluation of contralateral lobe and lymph nodeexcellent prognosis>95% 10-year survival rate
106Surgical Treatment of PTC - 1 Total or near-total thyroidectomyWhen PTC diagnosed by FNAB,definive surgery without frozenWhen probable PTC: thyroid lobectomy – if PTC confirmed in final histology:completion thyroidectomyIf minimal PTCs (<1 cm) confined to thyroid without angioinvasion: no further med surgery needed
107Surgical Treatment of PTC - 2 During thyroidectomy, enlarged central neck nodes should be removedBiopsy-proven lymph node metastases in lateral neck : modified radical or functional neck
109Follicular Carcinoma - 1 10% of thyroid cancersmore commonly in iodine-deficient areasfemale-to-male ratio of 3:1mean age at presentation:50 yr
110Presentation of Follicular Carcinoma Usually present as solitary thyroid nodulesOccasionally history of rapid size increaseHistory of long-standing goiterPain uncommon, unless hemorrhageUnlike papillary cancers, cervical LAP uncommon initially (about 5%), although distant metastases may be presentIn <1% hyperfunctioning, leading to thyrotoxicosis
111Diagnosis of Follicular Carcinoma FNAB unable to distinguish benign from carcinomasPreoperative diagnosis of cancer difficult unless distant metastases presentLarge follicular tumors (>4 cm) in older men: more likely to be malignant
112Surgery of Follicular Carcinoma When follicular lesion diagnosed by FNAB: lobectomy because at least 80% benign adenomasSome recommend total thyroidectomy in older patients with follicular lesions >4 cm (50%risk of cancer).Intraoperative frozen-section not helpfulTotal thyroidectomy should be performed when thyroid cancer is diagnosedNo prophylactic nodal dissection because nodal involvement infrequentIf nodal metastases: therapeutic neck dissection
113Prognosis of Follicular Carcinoma Cumulative mortality :15% at 10 years and 30% at 20 yearsPoor long-term prognosis predicted by:age over 50 years old at presentationtumor size >4 cmhigher tumor grademarked vascular invasionextrathyroidal invasiondistant metastases at time of diagnosis
115Hürthle Cell Carcinoma 3% of all thyroid malignanciesConsidered a subtype of follicular thyroid cancerNot diagnosed by FNABMore often multifocal and bilateral (30%)Do not take up RAIMore likely to metastasize to local nodes (25%) and distant sitesHigher mortality rate (20% at 10 yr)Surgical rules similar to follicular neoplasms
116Postoperative Management of Differentiated Thyroid Cancer
117Thyroid Hormone T4 is necessary as: replacement therapy after total or near-total thyroidectomysuppression of TSH and reducing the growth stimulus for any possible residual thyroid cancer cellsTSH maintained at about 0.1 in low-risk and <0.1 in high-risk patients
118Radioiodine TherapyScreening and treatment facilitated by removal of all normal thyroid tissue, which effectively competes for iodine uptakeMetastatic differentiated thyroid cancer detected and treated by 131I in 75%Early detection very important to improve prognosis
119Radioiodine TherapyT4 therapy discontinued weeks before scanning with 131IT3 during this time periodT3 discontinued 2 weeks to allow TSH to riseThe usual protocol : a screening dose of 1 to 3 mCi of 123I and measuring uptake 24 hours later. After a total thyroidectomy, this value should be <1%
120Follow-Up of Patients with Differentiated Thyroid Cancer
121Thyroglobulin Measurement Tg: <2 ng/mL in total thyroidectomy under T4therapy , and <5 when hypothyroidTg >2: metastatis or persistent normal thyroid tissueTg and anti-Tg antibody : measured initially at 6-month intervals and then annually
123MTC - 1 5% of thyroid malignancies Arises from the parafollicular or C cellsC cells secrete calcitoninConcentrated superolaterally in thyroid lobesMost sporadical25% with inherited syndromes ( familial MTC, MEN2A, and MEN2B)All the inheriteds secondary to mutations in the RET proto-oncogene
125MTC -2 Neck mass May palpable cervical LAP (15 to 20%) Pain or aching more commonLocal invasion may produce:dysphagiadyspneadysphoniaDistant blood-borne metastases to the liver, bone (frequently osteoblastic), and lung occur later
126MTC - 3 Female-to-male ratio is 1.5:1 50-60 yr Familial cases : younger ageIn extensive metastatic disease: diarrhea frequent2 to 4% develop Cushing's syndrome as a result of ectopic ACTH productionUnilateral (80%) in sporadic diseaseMulticentric in familial casesBilateral tumors in up to 90% of familial patients
127Diagnosis of MTC Established by : HistoryPhysical examinationRaised serum calcitoninRaised CEA levelsFNAB cytologyAttention to FH because 25% have familial disease
128Pheochromocytoma HPT Diagnosis of MTC Because not possible to distinguish sporadic from familial disease at initial presentation, all new patients with MTC should be screened for:RET point mutationsPheochromocytomaHPTCalcitonin and CEA: identify patients with persistent or recurrent MTC
129Surgery in MTC If harboring pheochromocytoma: operated on first Total thyroidectomy: treatment of choice because ofhigh incidence of multicentricitymore aggressive coursethe fact that 131I therapy usually is not effective
130In locally recurrent or metastatic disease, tumor debulking to: Surgery in MTCIn locally recurrent or metastatic disease, tumor debulking to:ameliorate symptoms of flushing and diarrheadecrease risk of death from recurrent central neck or mediastinal disease
131In carriers: Total thyroidectomy after confirmation of RET mutation MTC TreatmentIn carriers: Total thyroidectomy after confirmation of RET mutationbefore age 6 in MEN2Abefore age 1 in MEN2Bto improves survival rates
132Postop Follow-Up and Prognosis of MTC Follow up: Annual measurements of calcitonin and CEA levels10-year survival rate 80% but decreases to 45% with lymph node involvementPrognosis best in non-MEN familial MTC and worst in MEN2B.
134Anaplastic Carcinoma 1% of all thyroid malignancies Women more commonly affectedThe majority in 7th and 8th decades
135Symptoms in Anaplastic Carcinoma long-standing neck massrapid enlargementmay painfuldysphoniadysphagiadyspnea
136Signs in Anaplastic Carcinoma Large tumorMay be fixed to surrounding structuresMay be ulcerated with areas of necrosisLymph nodes usually palpableMay evidence of metastasis
137Diagnosis of Anaplastic Carcinoma Confirmed by FNABIncisional biopsy occasionally neededIsthmusectomy with or without tracheostomy may be needed to alleviate tracheal obstruction
138Treatment and Prognosis of Anaplastic Carcinoma One of the most aggressive thyroid malignanciesFew patients surviving 6 months beyond diagnosisAll forms of treatment :disappointingIf presentation as resectable mass: may small improvement in survival with thyroidectomy, especially in younger individualsCombined adjuvant RT and ChT in resectable disease: prolonged survivalTracheostomy may needed for airway obstruction
140Thyroid Lymphoma <1% of thyroid malignancies Most: non-Hodgkin's B-cell typeMay part of a generalized lymphomatous condition, but most develop in chronic lymphocytic thyroiditisUsually symptoms similar to anaplastic carcinoma, although often painlessMay presentation with acute respiratory distress
141Diagnosis of Thyroid Lymphoma Usually suggested by FNABCore needle or open biopsy may necessary for definitive diagnosisStaging studies should be obtained to assess extent of extrathyroidal spread
142Treatment of Thyroid Lymphoma Rapid response to chemotherapy (CHOP—cyclophosphamide, doxorubicin, vincristine, and prednisone), with improved survivalCombined treatment with RT and ChT often recommendedThyroidectomy and nodal resection for alleviation of airway obstruction if:no quick response to above regimensthose who have completed the regimen before diagnosis
143Prognosis of Thyroid Lymphoma Overall 5-year survival rate: 50%Much lower survival if extrathyroidal disease
145Thyroid : rare site of metastases Most metastases from: Metastatic CarcinomaThyroid : rare site of metastasesMost metastases from:KidneyBreastLungMelanoma
146Metastatic CarcinomaOften suggest the source of the metastatic disease:clinical examinationreview of the patient's historyDefinitive diagnosis: usually by FNABResection of the thyroid, usually lobectomy, may be helpful in many patients, depending on the status of their primary tumor.
147PapillaryFollicularHurthleMedullaryAnaplasticLymphomaPercent80%10%3%5%1%Age30-4050//50-60, <Fa60-80SexF/M=2/1F/M=3/1F/M=1.5/1F > MPainNoYesLNMetastasisYes...DiagnosisFNAFna-SxFNA,CalcitFNA/BxTreatmentTotal ThyLob-To ThyIsth,TrachChTPrognosisVery goodgoodFairFair-goodVery poorPoor-goodmultifocalYes,Fam?PointsChild,RTSubtype Fol25%fam,YoB Non Ho
148References:Lal G, Clark OH.Thyroid, parathyroid, and adrenal. In: Brunicardi FC AD, Billiar TR, Dunn DL, Hunter JG, Matthews JB, Pollock RE, editor. Schwartz’s Principles of Surgery. 9th ed. USA: McGraw-Hill; pSearch results in on the image sections :