Detection of hepatic metastasis from medullary thyroid cancer with Tc-99m-MIBI scintigraphy in a patient with Sipple's syndrome.

We report a case of Sipple's syndrome with a hepatic tumor. A 28-year-old male with medullary thyroid cancer and bilateral pheochromocytomas was diagnosed as having Sipple's syndrome. The hepatic tumor was found to be hypervascular by means of a dynamic abdominal CT scan. An I-131-MIBG scan showed no increased accumulation in the tumor. A whole body Tc-99m-MIBI scan had shown, however, increased accumulation in the tumor by 10 minutes after i.v. Tc-99m-MIBI. The hepatic tumor was diagnosed histologically as a metastasis from the medullary thyroid cancer. To our knowledge, there have been no previous reports of increased Tc-99m-MIBI accumulation in hepatic metastases from medullary thyroid cancer.