Fine needle aspiration biopsy of medullary carcinoma of the thyroid metastatic to the liver. A case report.

A 59-year-old female with a six-month history of medullary carcinoma of the thyroid (MCT) presented with multiple liver nodules and several physical complaints. Ultrasound-guided fine needle aspiration biopsy (FNAB) of the liver established the diagnosis of metastatic MCT. This report describes the usefulness of FNAB, aided by immunocytochemical and ultrastructural studies, in patients with MCT in whom liver metastases are suspected.