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In the Nam e of G od. SURGICALTHYROID DISEASES. Sadaf Alipour Surgical Oncologist Assistant Professor Arash Women’s Hospital Tehran University of Medical Sciences. Our Subject:. What to operate? When to operate? How to operate?. Surgery Goals (general).
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SURGICALTHYROIDDISEASES Sadaf Alipour Surgical Oncologist Assistant Professor Arash Women’s Hospital Tehran University of Medical Sciences
Our Subject: • What to operate? • When to operate? • How to operate?
Surgery Goals (general) • An organ has a malfunction that cannot be treated madically • An organ is getting huge sizes and the pressure effects cannot be treated medically • An organ harbors a mass/tumor that must be excised • There is a mal-placed or developmental anomaly that needs to be excised
Thyroglossal Duct Cyst and Sinus • The most commonly encountered congenital cervical anomalies • Anywhere along the migratory path of the thyroid • 80% in juxtaposition to the hyoid
Thyroglossal Duct Cyst and Sinus • heterotopic thyroid tissue in 20% • usually asymptomatic • occasionally infected by oral bacteria: thyroid duct sinus secondary drainage of the cyst • Accompanied by minor inflammation of surrounding skin
Diagnosis 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 necessary • Thyroid scintigraphy and ultrasound: document the presence of normal thyroid tissue in the neck.
Surgery of Thyroglossal Duct Cyst and sinus • "Sistrunk operation“ en bloc cystectomy and excision of the central hyoid bone to minimize recurrence.
!!!of Thyroglossal Duct Cyst and sinus • 1% contain cancer, 85% papillary • Squamous, Hürthle cell, and anaplastic cancers also reported but rare. • Medullary thyroid cancers (MTCs) are not found in thyroglossal duct cysts. • Role of total thyroidectomy controversial • Surgery advised in older patients with large tumors, particularly if with additional thyroid nodules and evidence of cyst wall invasion or lymph node metastases.
Lingual Thyroid • Failure of median thyroid anlage to descend normally • May the only thyroid tissue present
Treatmentin Lingual Thyroid • Necessary only if : 1) Obstructive symptoms: • choking • dysphagia • airway obstruction • hemorrhage 2) Hypothyroidism ( frequent) • Medical treatment : • exogenous thyroid hormone or • RAI ablation followed by hormone replacement
Surgery in Lingual Thyroid • Surgical excision rarely needed • If required, should be preceded by evaluation of normal thyroid tissue in the neck to avoid inadvertently rendering the patient hypothyroid
Ectopic Thyroid • Found anywhere in the central neck compartment • esophagus • trachea • anterior mediastinum • adjacent to the aortic arch • in the aortopulmonary window • within the upper pericardium • in the interventricular septum • Often, "tongues" of thyroid tissue seen extending off the inferior poles particularly in large goiters
!!! in Ectopic Thyroid • When thyroid tissue lateral to carotid sheath and jugular vein (termed lateral aberrant thyroid): almost always metastatic thyroid cancer in lymph nodes • Even if not apparent on exam or US, the ipsilateral thyroid lobe contains a focus of papillary thyroid cancer (PTC), which may be microscopic.
Pyramidal Lobe • In 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 palpable • In thyroid hypertrophy : enlarged and palpable
Surgery Goals (general) • An organ has a malfunction that cannot be treated madically • An organ is getting huge sizes and the pressure effects cannot be treated medically • An organ harbors a mass/tumor that must be excised • There is a mal-placed or developmental anomaly that needs to be excised
Diffuse Toxic Goiter Graves’ Disease
Diffuse Toxic Goiter (Graves' Disease) • Etiology of autoimmune process: not known • Thyroid gland diffusely and smoothly enlarged
Clinical Features of Graves Disease • Divided into • those related to hyperthyroidism • those specific to Graves' disease
Clinical Features ofhyperthyroidism in Graves Disease • tremors • diarrhea • women: • amenorrhea • decreased fertility • miscarriages • children: • rapid growth • early bone maturation • older patients: • AF • CHF • Hyperthyroid symptoms: • heat intolerance • increased sweating • hair loss • weight loss despite adequate caloric intake • palpitations • nervousness • fatigue • emotional lability
Clinical Features of Hyperthyroidism in Graves Disease • fine tremor • muscle wasting • proximal muscle group weakness • hyperactive tendon reflexes • On physical examination: • weight loss • facial flushing • warm and moist skin • african americans: darkening of skin • tachycardia or atrial fibrillation • widening of the pulse pressure
Clinical Features Specific toGraves Disease • 50% : ophthalmopathy • spasm of the upper eyelid revealing the sclera above the corneoscleral limbus (Dalrymple's sign) • prominent stare, due to catecholamine excess • lid lag (von Graefe's sign) • periorbital edema • conjunctival swelling and congestion (chemosis) • keratitis • proptosis • limitation of upward and lateral gaze (from involvement of the inferior and medial rectus muscles, respectively) • blindness due to optic nerve involvement
Clinical Features Specific toGraves Disease • 1-2%: dermopathy : deposition of glycosaminoglycans leading to thickened skin in pretibial region and dorsum of the foot • Gynecomastia common in young men • Rare subperiosteal bone formation and swelling in metacarpals (thyroid acropachy) • Onycholysis, or separation of fingernails from their beds
Clinical Features of Graves Disease • On physical examination: • thyroid usually diffusely and symmetrically enlarged • enlarged pyramidal lobe • may bruit or thrill and loud venous hum in supraclavicular space
Diagnostic Tests for Graves’ disease • Suppressed TSH • Elevated /NL f T4 or T3 or f T3 • If eye signs present, other tests generally not needed. • If no eye findings: RAIU scan necessary • Confirms diagnosis: elevated uptake and diffusely enlarged gland • Elevated Anti-Tg and anti-TPO in75%, non-specific • Elevated TSH-R or thyroid-stimulating Abs (TSAb):in 90% :diagnostic • MRI of orbits: useful in evaluating ophthalmopathy.
? Treatment ? • May be treated by: • antithyroid drugs • thyroid ablation with radioactive 131I • surgery ?
Antithyroid Drugs • Generally used in preparation for RAI ablation or surgery • Drugs 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
RAI 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 goiters • relapse after medical or surgical therapy • Contraindication of antithyroid drugs or surgery • Absolute contraindications to RAI: • pregnant or breastfeeding women • Relative contraindications : • young patients (i.e., especially children and adolescents) • thyroid nodules • ophthalmopathy
RAI for Treatment of Graves’ Disease • The major advantages: • no surgery • reduced overall treatment costs • ease of treatment • Antithyroid drugs given until euthyroid • Only 50% euthyroid 6 months after treatment • The remaining still hyperthyroid or already hypothyroid • After 1 year, 2.5% develop hypothyroidism each year • The higher the initial dose of 131I, the earlier the onset and the higher the incidence of hypothyroidism
Surgical 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 therapy • Relative indications: • Moderate to severe Graves' ophthalmopathy particularly in smokers • desiring rapid control of hyperthyroidism with a chance of being euthyroid, • poor compliance to antithyroid medications
Type of Surgery in Graves’Disease • total or near-total thyroidectomy • cancer • refuse RAI therapy • severe ophthalmopathy • life-threatening reactions to antithyroid medications (vasculitis, agranulocytosis, or liver failure) • Subtotal thyroidectomy (leaving a 4- to 7-g remnant) • all remaining patients
Surgical Treatment of Graves’ Disease • Antithyroid drugs given up to the day of surgery to be euthyroid • Generally Lugol's iodide solution beginning 7 to 10 days preoperatively (three drops twice daily) to reduce vascularity and risk of precipitating thyroid storm
Toxic Multinodular Goiter • Often a prior history of nontoxic multinodular goiter • Over several years, enough thyroid nodules become autonomous to cause hyperthyroidism. • Usually in older people
Presentation in Toxic MNG • Symptoms and signs of hyperthyroidism similar to Graves’, extrathyroidal manifestations absent • Presentation of hyperthyroidism often insidious • May hyperthyroidism only apparent when on low dose thyroid hormone suppression for goiter • May hyperthyroidism precipitated by iodide-containing drugs(jodbasedow hyperthyroidism): • contrast media • amiodarone
Diagnostic Studies in Toxic MNG • Blood tests are similar to Graves: • Suppressed TSH • Elevated free T4 or T3 • RAIU increased: multiple nodules with increased uptake and suppression of the remaining gland
Treatment of Toxic MNG • Preferred treatment: Surgery • Standard procedure:Subtotal thyroidectomy • Remnant size not crucial because these require thyroid suppression to prevent recurrence
Treatment of Toxic MNG • RAI reserved for : Elderly with very poor operative risks if • no airway compression from the goiter and • thyroid cancer not a concern. • Uptake is less than in Graves' disease: larger doses of RAI needed • RAI-induced thyroiditis may cause swelling and acute airway compromise, and leaves the goiter intact, with the possibility of recurrent hyperthyroidism
Toxic Adenoma • RAIU: "hot" nodule with suppression of rest of thyroid • Recent growth of a long-standing nodule • Hyperthyroidism from a single hyperfunctioning nodule • Symptoms of hyperthyroidism, typically in younger patients • Physical examination : solitary thyroid nodule without palpable thyroid tissue on contralateral side
Treatment of Toxic Adenoma • Smaller nodules: • antithyroid medications • RAI • Surgery (lobectomy and isthmectomy): preferred for: • young patients • larger nodules
Thyroiditis • Classification: • acute • subacute • chronic each associated with a distinct clinical presentation and histology.
Acute (Suppurative) Thyroiditis • Thyroid : resistant to infection • Often preceded by upper respiratory tract infection or otitis media • More common in children • 70%: Streptococcus and anaerobes