Synchronous medullary carcinoma of thyroid and ductal carcinoma of breast: A report of a rare case with immunohistochemical study

Synchronous malignancies of breast and thyroid have been rarely documented in literature. The reports of secondary malignancies after thyroid cancer and treated breast cancer are relatively not uncommon. We encountered a case of thyroid tumor coexisting with carcinoma of breast. On histopathological and immunohistochemical (IHC) studies, the thyroid was involved by medullary carcinoma and the breast revealed invasive ductal adenocarcinoma. The rarity of this association has prompted us to report this case.