Mixed medullary-follicular thyroid carcinoma. Report of a case and review of the literature

OBJECTIVE: The aim was to describe the case of a female patient with a mixed medullary-follicular thyroid carcinoma. METHODS: The patient underwent thyroidectomy for the treatment of multinodular goiter. A tumor was found which exhibited the features of a mixed medullary-follicular thyroid carcinoma. Immunohistochemistry was performed. RESULTS: Immunohistochemistry was positive in the area of the carcinoma for calcitonin and thyroglobulin. She developed extensive metastatic deposits in the bones of the pelvis and in the calvarium causing hyperthyroidism. CONCLUSION: A patient with a mixed medullary-follicular thyroid carcinoma is described, who had elevated levels of both calcitonin and thyroglobulin and developed metastatic deposits, which could produce thyroid hormones.