Cystic medullary thyroid carcinoma: Report of a case with morphological and clinical correlations

Cystic lesions of the thyroid are common findings. Although many thyroid cy sts are of benign, some cases of hemorrhagic degenerative changes occur in neoplastic nodules, mostly follicular neoplasms and papillary carcinomas. T he occurrence of hemorrhagic changes in medullary carcinomas has never been documented with aspirative cytological and histological pictures to the be st of our knowledge. A case of medullary thyroid carcinoma with a large cen tral hemorrhagic cyst is described, and the literature regarding the pathog enesis of this regression and the occurrence of cystic neoplasms in the thy roid is reviewed.