Needle biopsy of solitary thyroid nodule in a young woman with palpable cervical lymph nodes on the same sides demonstrates amyloid in stroma of lesion. Likely diagnosis is

Answer is A (Medullary Carcinoma thyroid) Presence of thyroid nodule along with palpable cervical lymph nodes and amyloid histologically is clearly indicative of Medullary variety of Carcinoma Thyroid. Medullary Carcinoma thyroid : It is a neuroendocrine carcinoma rising from parafollicular 'C' cells of thyroid Parafollicular 'C' cells are derived from neural crest and secrete calcitonin. Medullary carcinoma should be suspected whenever : a. High level of serum calcitoninQ are discovered b. Cervical lymph node are discovered at time of presentation. Q - Involvement of lymph nodes occurs early.Q - Thyroid and blood born metastasis occurs early.Q c. DiarrheaQ is a presentation d. AmyloidQ is present in stroma histologically. e. MEN setting : Evidence of Pheochromocytoma / Hyperparathyroidism / Thyroid cancer in family. (Discovery of medullary carcinoma thyroid makes family surveillance advisable).ef Hypocalcemia is associated: These cancers are associated with HypocalcemiaQ because calcitonin is secreted. Medullary carcinoma thyroid is seen as ? Sporadic : 80% Familial : 20% - Non MEN setting / MEN II a / MEN II b