GOITER

Ans is ‘a’ i.e., Follicular carcinoma 

“An increased incidence of cancer (usually follicular) has been reported from endemic areas. Dominant or rapidly growing nodules in longstanding goiters should always be subjected to aspiration cytology.” – Bailey & Love

• About Follicular Carcinoma (FTC)
• FTC are second most common thyroid malignancies, more common in iodine-deficient areas.
• More common in women (Female : Male ratio of 3:1)
• Mean age of presentation is later than papillary Ca (— 50 yrs)
• Multiple foci are rarely seen and lymph node involvement is much less common than in papillary carcinoma.
• Blood borne metastasis is common with spread to bone, lungs, liver and elsewhere.
• In less than 1% of cases, follicular cancers may be hyperfunctioning (warm nodule on scintiscan), leading to symptom of thyrotoxicosis.
• Histopathology

Follicular carcinomas are usually solitary lesions, the majority of which are encapsulated.

Microscopically most follicular carcinomas are composed of fairly uniform cells forming small follicles containing colloid (quite like normal thyroid). In other cases follicular differentiation may be less apparent, and there may be nests or sheets of cells without colloid.

the nuclei lack the typical features of papillary Ca.

Ans. is ‘c’ i.e. Radio iodine 

• Jod–Basedow effect is characterized by iodine-induced hyperthyroidism.
• In patients with endemic goiter, excessive thyroid hormone synthesis can be caused by increased iodine exposure either as a dietary supplement or as a contrast medium.
• The Jod-Basedow effect is named after “jod”, the German word for iodine, and Carl Adolph von Basedow, the German physician who first described the effect.
• It is due to overactivation of the thyroid gland or autonomous nodules within the gland after iodine repletion without adequate feedback control from the pituitary gland. This phenomenon does not occur in individuals with the normal thyroid gland.
• Wolff–Chaikoff effect is iodine-induced suppression of the thyroid gland.
• In individuals with a normal thyroid, excess iodide transiently inhibits thyroid iodide organification and thyroid hormone production. However, in patients with underlying autoimmune thyroid disease, the suppressive action of high iodide may persist.
• Clinical relevance: The Wolff–Chaikoff effect has been used as a treatment principle against thyroid storm by infusion of a large amount of iodine to suppress the thyroid gland.
• Note: Somogyi effect and Dawn phenomenon are associated with Diabetes mellitus, not thyroid disease.

Answer is B (Diffuse Goiter) :

‘Euthyroid state is generally the rule’ – Robbins

Endemic goiter  :occurs in geographical areas where the soil, water and food supply contains only low levels of iodine. The lack of the iodine leads to decreased synthesis of thyroid hormones and a compensatory increase in TSH, which in turn leads to follicular cell hypertrophy and hyperplasia and goitrous enlargement – Diffuse hyperplastic goitre. ‘Euthyroid state is generally the rule’ ‘Rare patients are hyperthyroid’

Ans. A i.e. Follicular carcinoma

Thyroid carcinoma

• Rarest: Anaplastic Ca
• Worst prognosis: Anaplastic Ca
• Best prognosis: Papillary Ca
• Associated with MEN II: Medullary Ca
• Developing in thyroglossal cyst: Papillary Ca
• Least malignant: Papillary Ca
• Developing in Hashimoto’s thyroiditis: Papillary Ca
• MC type: Papillary Ca
• Associated with psammoma bodies: Papillary Ca

Ans. c. All nodules > 4 cm should be resected irrespective of cytology

Approximately 50% of these nodules decrease in size in response to the TSH suppression of this regimen, and others may
not continue to grow, but it is most effective for nodules <3 cma
Hemithyroidectomy: lf a nodule enlarges on TSH suppression, causes compressive symptoms, or for cosmetic reasons.
Total thyroidectomy: Patient who has had previous irradiation of the thyroid gland or has a family history of thyroid
cancer, because ofthe high incidence ofthyroid cancer and decreased reliabitity ofFNAC in this setting

Answer- (A) Size may increase during pregnancy (B) Usually hypothyroid (D) Can turn malignant

• Endemic Goiter is the presence of a goiter caused by nutritional deficiency of Iodine.

Effect of pregnancy-

• Increased endocrine demand the iodine metabolism is characterized by the tendency to develop an endogenous iodine deficiency (ID).
• Diffuse thyroid gland hypertrophy can be visibly observed as a goiter ofthe neck.
• Endemic Goiter is ultimately caused by reduced thyroid hormone levels it is accompanied by the clinical syndrome of hypothyroidism.
• Irregular, nodular goiters due to repeated bouts ofiodine deficiency may progress to thyroid follicular carcinoma.