Hypocalcemia associated with a calcitonin-producing hepatocellular carcinoma.

We report a case of symptomatic hypocalcemia with a calcitonin-producing tumor. This case is unusual for two reasons. First, the primary tumor was a hepatocellular carcinoma that was producing large amounts of calcitonin. To our knowledge, well-defined cases of calcitonin-secreting hepatoma have not been previously reported. Second, the patient's hypercalcemia was shown to be secondary to hypomagnesemic inhibition of parathyroid function and not related to hypercalcitonemia.