[Malignant insulinoma]

Authors present the history of a 56-year-old man who was evaluated for recurrent epigastric pain. Clinical investigation revealed a 4-cm tumor in the head of the pancreas and a solitary liver metastasis. Pathological examination of the surgically excised pancreatic tumor indicated a moderately differentiated neuroendocrine carcinoma and Ki-67 labeling index revealed moderate proliferative activity. Despite short-term chemotherapy combined with interferon and somatostatin analogue administration, the metastatic disease rapidly progressed. Octreotide scintigraphy disclosed abundant expression of somatostatin receptors both on primary tumor and hepatic metastases. ⁹⁰Yttrium-DOTATOC treatment was performed in three sessions within 9 months (3 x 200 mCi) with a mixed therapeutic response. Endocrine symptoms were not observed during the first 33 months of the disease. 34 months after the initial diagnosis of the neoplastic disease, imaging studies and chromogranin A measurement revealed rapidly progressing disease and the patient developed frequent episodes of hypoglycemic attacks. Serum insulin and C-peptide measurements confirmed insulin oversecretion. Continuous administration of somatostatin analogue was supplemented with diazoxide, but the latter therapy was not tolerated because of severe water retention. The high dose oral carbohydrate intake was supplemented with continuous glucose infusion. As a rescue procedure, repeated liver chemoembolization was performed, which resulted only in a short-term effect. The autopsy and the immunohistochemical investigations confirmed the diagnosis of insulin-producing, metastatic neuroendocrine carcinoma.