MUCOEPIDERMOID CARCINOMA OF THE THYROID-GLAND ARISING FROM A PAPILLARY EPITHELIAL NEOPLASM

We report a case of mucoepidermoid carcinoma of the thyroid gland. The simultaneous association of papillary and mucoepidermoid carcinoma in a Hashimoto's thyroiditis makes the present observation unusual. Surg ery was limited due to local extension of the neoplasm. The patient co nsequently underwent external radiotherapy followed by radiometabolic therapy. The patient survived 11 months after diagnosis. As far as the histogenesis of the neoplasm is concerned, we believe that mucoepider moid areas correspond to squamous and mucinous metaplasia of a preexis ting papillary carcinoma. Transition areas between elements morphologi cally characteristic of both neoplasms were observed. Histochemical an d immunohistochemical studies confirmed the diagnosis of a carcinoma w ith multiple aspects showing a focal positive reaction for thyroglobul in or keratin antisera. Therefore, this demonstrates different functio nal activities of the neoplastic cells. There is still debate about ad juvant therapies, the results of which appear for the moment very poor .