Endocrine Abstracts

Introduction: Malignant insulinoma is a rare functional endocrine tumor of the pancreas. Therefore, there are few data regarding their optimal therapy and long term prognosis. Malignancy is defined by the presence of metastases, mostly in lymph nodes or the liver. Generally these patients present with severe hypoglycemia and require multiple therapies. Here, we described the management of a patient with malignant insulinoma.

Case: A 41-year-old woman with symptomatic and proven hypoglycemia, presented with a 11×10 mm hypodense cystic lesion and a 16×14 mm hyperdense lesion in the tail of the pancreas, and multiple liver metastases following a computerized tomography (CT) scan. Distal pancreatectomy, splenectomy and biopsy from the metastatic liver lesions were performed. Pancreatic resection showed evidence of tumor infiltration into the peripancreatic adipose tissue and extense perineural and lymphovascular invasions. 4 of the 15 resected lymph nodes were evaluated as metastatic. The ki-67 proliferation index of the insulinoma was 7.8%. After surgery, the patient was treated with 120 mg lanreotide autogel/28 days, and with 100 mg of diazoxide two times a day. Dexamethasone therapy was started with 4 mg daily and progressively increased to 16 mg daily. Selective internal radiation therapy with yttrium-90 (Y-90) was administered to treat liver metastases. But the patient did not have benefit from radiation therapy. The patient was evaluated for the liver transplantation because Ga68 scintigraphy showed metastases only in the liver. Although dexthamethasone, lanreotide and diazoxide therapies, hypoglycemic episodes reappeared and she was rehospitalised for persisted hypoglycemia and diuretic resistant edema. Diazoxide was stopped after 6 weeks. Intravenous glucose (10–20% dextrose) infusion and subcutaneous glucagon average 1–2 ampules/day administration were performed. Oral everolimus at a dose of 10 mg/day was also started. Hypoglycemia did not resolve and then parenteral nitrution was performed. Chemotherapy was planned but general status of the patient was deteriorated and patient had respiratory distress due to probably infection or drug associated pneumonitis. Brochoscopy was planned but general status of the patients did not permit the procedure. She died from acute respiratory distress syndrome(ARDS) 3 months after the initial diagnosis.

Conclusion: Refractory hypoglycemia in patients with metastatic insulinoma is an important cause of morbidity and mortality. Surgery is the only curative treatment but does not mostly solve the hypoglycemia caused by malignant insulinomas. For our patient, although hypoglycemic episodes were controlled with aggressive medical treatment, she died due to respiratory distress.