A case of liver metastasis from follicular cell carcinoma of the thyroid with similar image findings to hepatocellular carcinoma

Abstract

A 63-year-old woman was admitted to our hospital for examination of a liver tumor following slight elevation of γ-GTP levels. Ultrasonography (US) showed a round, inhomogeneous tumor approximately 80 mm in diameter in the right lobe. Dynamic computed tomography, Gd-EOB-DTPA-enhanced magnetic resonance imaging and contrast-enhanced US demonstrated hypervascular tumor with enhancement in the arterial phase and wash-out in the delayed phase. The center of the tumor was not enhanced in any phase. Based on these findings, we suspected simple nodular-type hepatocellular carcinoma (HCC) with central necrosis. However, the patient had no history of chronic liver disease. Negative results were obtained for hepatitis virus markers and tumor markers. Spinal MRI showed a 10-mm hypervascular tumor at L4, suggesting bone metastasis. Despite this finding, we performed right hepatectomy with the objective of local control. Histological findings showed a follicular formation containing colloidal tissue. Since this patient had a past history of thyroid lobectomy for follicular adenoma at 43 years old, we diagnosed the liver tumor as metastatic tumor from follicular cell carcinoma of the thyroid. This case suggests that metastasis from thyroid cancer should be considered as a differential diagnosis for liver tumor with hypervascular findings such as HCC.