Endocrine Abstracts

Insulinoma is a rare neuroendocrine tumor (4 cases/1000000/year), less than 10% are malignant. We report a case of rapidly fatal malignant insulinoma, death occurring less than 3 months after the apparition of hypoglycaemic symptoms.

A 79 years old female type 2 diabetic patient, treated with glicazide120 mg b.i.d and metformine et 850 t.i.d, was hospitalized for recurrent hypoglycaemia Insulinoma was diagnosed as severe hypoglycaemic episodes occurred more and more frequently despite withdrawal of all hypoglycaemic agents. Concomitantly insulin plasma levels were not adapted to glycaemia: glycaemia 42 mg/dl et insulinemia 60.9 μU/ml while sulfonylurea dosages were negative. CT scan found multiple secondary hepatic lesions of 3 to 30 mm all over the liver and 2 cystic tumours of the caudal part of pancreas. Chromogranin A was 4040 μg/l (N<100), NSE was 220.8 ng/ml (N<17). Calcitonin, Gastrin, Serotonin, VIP were in the normal range. Hypoglycaemia episodes were dramatically improved by associating diazoxide 500 mg/day to Somatuline LP 30 mg° / 15 days and dextrose 30% 500 ml/day. Due to liver secondary localisation clinical status of the patient deteriorated rapidly and increasing peripheral oedema associated to renal failure, patient was transferred to ICU. A programmed hepatic chimio-embolization was postponed due to severe renal failure and alteration of general status and death occurred due to hepatic insufficiency. Anatomopathology of the hepatic biopsy showed a marked expression of antibodies against chromogranin A, secondary analysis concluded to a well differentiated endocrine carcinoma without any immunochemistry staining against insulin, glucagon, gastrin or somatostatin. Malignant insulinoma prognosis is less than 2 years after surgery. Prognosis of malignant insulinoma is classically worse when hepatic localisations are present at diagnosis. An immunotherapy as proposed in the parathyroid carcinoma could eventually improve the prognosis.