Nearly 15 years have passed since Hazard et al.1 delineated medullary carcinoma of the thyroid gland (MCT) as a distinct pathologic entity. Since the initial description more than 250 cases have been reported, a number far out of proportion to the frequency of the tumor among thyroid carcinomas, as it comprises less than 10% of all malignancies of this gland.2 Much of this seemingly excessive interest in MCT has arisen because of the unusual features of the tumor itself. It is pleomorphic in appearance, generally presenting as a spindle- or small-cell carcinoma occurring in solid sheets, rosettes, and even a papillary or pseudofollicular pattern.