Malignant Insulinoma
Article Outline
A previously healthy 62-year-old man was admitted to the hospital because of a 3-week history of diffuse abdominal pain and dyspepsia. On the morning of admission, he reported asthenia, sweating, and dizziness. On physical examination, the only remarkable sign was hepatomegaly of 10 cm. Laboratory results showed increased liver enzyme levels (aspartate transaminase, 87 IU/L [normal range, 0–25 IU/L]; alanine transaminase, 50 IU/L [normal range, 0–29 IU/L]; γ-glutamyltransferase, 122 [normal range, 5–38 IU/L]; alkaline phosphatase, 251 [normal range, 65–195 IU/L]) with normal prothrombin time and albumin levels, glucose level of 35 mg/dL, and an insulin level of 56.1 mIU/L (normal range, 1.5–18.5). An abdominal ultrasound and a computed tomography scan (see Figure) showed a mass in the tail of the pancreas of 45 × 28 mm (white arrow), multiple liver nodes, and portal-splenic thrombosis (arrow). A fine-needle aspiration of liver nodes guided by ultrasonography revealed cells with positive staining for chromogranin, synaptophysin, and neuronal-specific enolase and was diagnosed as insulinoma. The patient underwent a corpus and tail pancreatic resection together with splenectomy and splenoportal thrombectomy. The postoperative course was complicated by hypoglycemia despite treatment with octreotide. He developed abdominal sepsis and metastatic respiratory distress and died.
Insulinoma is one of the most common neuroendocrine tumors, yet the incidence of insulinoma is only 1–4 cases per million people per year.1 These tumors usually are benign, small, and solitary. Only 10% are malignant, with invasion of lymphatic nodes and liver metastases.2 The clinical symptoms are caused by the effect of hypoglycemia on the central nervous system and by the excess of catecholamines released secondary to hypoglycemia. There are diverse measures to control hypoglycemia, but the curative treatment is surgical, and in malignant cases, chemotherapy must be used.1, 2 The long-term survival is reduced in malignant cases (29% vs 88% at 10 years after surgery).1
This is a striking case for several reasons. First, in this patient the most remarkable clinical symptoms were abdominal pain and hepatomegaly, but the hypoglycemic symptoms were relevant only on the morning of admission. Initially, the clinical diagnosis was pancreatic carcinoma with liver metastases. Moreover, insulinomas usually are small and the location before surgery often is unclear, even with abdominal scans,2 but in this case the abdominal ultrasound showed a large pancreatic mass with liver metastases. Finally, another unusual finding was the portal-splenic tumoral thrombosis that could be seen in pancreatic diseases but is rarely associated with insulinoma.3
References
PII: S1542-3565(04)00724-4
© 2006 American Gastroenterological Association. Published by Elsevier Inc. All rights reserved.
