3 cm palpable nodule in one lobe of an otherwise normal sized thyroid gland

[Oak]

During a preemployment physical, a 47 year-old man is noted to have a 3 cm palpable nodule in one lobe of an otherwise normal sized thyroid gland. Needle aspiration of the nodule demonstrates polygonal tumor cells and amyloid, but only very scanty colloid and normal follicular cells. Which of the following is the most likely diagnosis?

A. Follicular thyroid carcinoma
B. Hashimoto's disease
C. Medullary thyroid carcinoma
D. Papillary thyroid carcinoma
E. Thyroid adenoma

[TIME]

3 cm palpalble nodule in one lobe and another lobe normal size in a thyroid thyroid gland with differentiating cells and amyloid but very scanty colloid and normal follicular cells hummmmmmmm !!!!! is it medullary thyroid carcinoma?????????

[drdevil]

medullary thyroid carcinoma. it is the one with polygonal tumour cells and amyloid..a nd scanty normal follicular cells.
in follicular types the normal architech. is more or less preserved, there r no inflammatory cells to call it thyroiditis.

[Hero]

yup, i also go for (C) medullary thyroid Ca

[kenneth masamaro]

I'd go for medullary ca.But hey Oak, is there something we are not seeing.coz the polygonal cells and elaboration of amyloid was a give away.
Remember the clinical criteria of thyroid nodules;

A solitary nodule is more likely to be neoplastic than multiple nodules

A solitary nodule in a young patient is more likely to be neoplastic than the same nodule in an older patient

A solitary nodule in a male is more likely to be neoplastic than the same in a female

[Oak]

Sorry guys, I got little late, yh, the correct answer is C. The most distinctive clue is the presence of amyloid, which specifically suggests medullary thyroid carcinoma. This carcinoma is a tumor of the neuroendocrine parafollicular cells of the thyroid, rather than the follicular lining epithelium. These cells produce calcitonin, the precursor protein of which can precipitate, forming bands and nodules of amyloid that appear histologically identical to other forms of amyloid. The other thing to remember about medullary carcinoma of the thyroid is that it can be a component of multiple endocrine neoplasia (MEN) syndromes type IIa (parathyroid disease, pheochromocytomas, medullary carcinoma) and type IIb (parathyroid disease, pheochromocytomas, medullary carcinoma, mucocutaneous ganglioneuromas, Marfanoid habitus).

Because follicular thyroid carcinoma (choice A) closely resembles normal thyroid tissue, it usually cannot be reliably diagnosed based on fine needle aspiration alone.

Hashimoto's disease (choice B) would show lymphocytes, plasma cells, and macrophages on aspiration.

Papillary thyroid carcinoma (choice D) can be diagnosed by aspiration if papillary clusters are seen.

Thyroid adenoma (choice E) cannot be reliably distinguished from well-differentiated thyroid carcinoma on aspiration.