Sequential hypoglycemia, hyperglycemia, and the carcinoid syndrome arising from a plurihormonal neuroendocrine...

To describe the first patient with a neuroendocrine tumor secreting serotonin, insulin, and glucagon and having the corresponding clinical syndromes.

We present a detailed case report, including serial laboratory and clinical findings, in a man with type 2 diabetes, symptomatic hypoglycemia, and the carcinoid syndrome and in whom a plurihormonal metastatic neuroendocrine neoplasm was ultimately diagnosed.

In a 58-year-old man with type 2 diabetes, which was treated effectively with a sulfonylurea for 7 years, episodes of hypoglycemia developed. After discontinuation of the orally administered agent, the hypoglycemic episodes initially resolved but then recurred and were associated with inappropriately increased plasma insulin concentrations. In addition, the patient had symptoms and biochemical evidence of the carcinoid syndrome. Computed tomography of the abdomen showed multiple hypodense lesions in the liver, and ultrasound-guided fine-needle aspiration of a liver mass was performed. Undifferentiated neuroendocrine tumor with hepatic metastatic involvement was diagnosed. After a hepatic artery embolization procedure, the hypoglycemia was alleviated, but hyperglycemia soon recurred, associated with inappropriately increased serum glucagon concentrations. The patient's course strongly suggested the presence of a plurihormonal tumor secreting serotonin, insulin, and glucagon.

To our knowledge, this is the first reported case of a patient with a neuroendocrine neoplasm secreting serotonin, glucagon, and insulin, manifested by the carcinoid syndrome, hyperglycemia, and hypoglycemia.