Hepatocellular carcinoma: an unusual course with hyperthyroidism and inappropriate thyroid-stimulating hormone production.

A 61-yr-old woman was found to have multicentric hepatocellular carcinoma associated with clinical hyperthyroidism. Marked elevations in serum thyroid-stimulating hormone, T4, T3, and free T4 were documented. These values increased with tumor progression. It is postulated that this patient's hepatoma produced a substance stimulating thyroid-stimulating hormone synthesis and secretion with resultant inappropriate thyroid-stimulating hormone production and thyrotoxicosis. This unusual association of hepatocellular carcinoma with clinical and biochemical evidence of hyperthyroidism and inappropriate thyroid-stimulating hormone production has not been previously reported.