Malignant hypercalcemia due to gastric endocrine cell carcinoma.

A 62-year-old man was admitted to our Neurology Unit due to consciousness disturbance. Laboratory data showed marked hypercalcemia and azotemia. Serum parathyroid hormone-related protein (PTHrP) level was extremely high. We performed intensive hemodialysis for renal failure, but his condition deteriorated rapidly. On day 10, he died of multiple organ failure. The autopsy revealed gastric undifferentiated adenocarcinoma with systemic dissemination. Immunohistological study showed positive PTHrP staining in carcinoid-like parts of the tumor. This is the first reported case of malignant hypercalcemia due to PTHrP-producing carcinoid or endocrine cell carcinoma of the stomach.