Amyloid deposition is seen in which type of carcinoma thyroid: September 2009

Ans. D: Medullary Medullary tumors have an ominous histologic pattern, with solid masses of cells with large vesicular nuclei. There may be considerable associated fibrosis, and deposits of amyloid are a helpful diagnostic point. These tumors are entities distinct from the undifferentiated cancers and medullary carcinomas have a much better prognosis. Medullary thyroid carcinoma (MTC) is associated with amyloid deposition in the surrounding tissues. Full-length calcitonin is the sole constituent of amyloid in MTC.