Cystic endocrine tumors of the pancreas: clinical, radiologic, and histopathologic features in 13 cases.

Cystic endocrine tumors of the pancreas are rare and raise difficult clinical problems. Our aims were to reevaluate the diagnostic and therapeutic strategy and to assess their histopathologic characteristics. Thirteen cystic endocrine tumors diagnosed in 10 patients were included. Clinical, radiologic, and pathologic data were reviewed. There were 6 male and 4 female patients (median age, 46 yrs). Six patients had evidence of multiple endocrine neoplasia type 1 (MEN1) disease. Four had a functional endocrine syndrome. Ten tumors were visible on imaging studies. The most suggestive radiologic features were the existence of a peripheral hypervascular rim (10 cases) and images of cyst into cyst (two cases). On gross and histologic examinations, two distinct types were present. Macrocystic tumors (six cases) were unilocular and limited by a thick wall containing nests of tumor cells. Microcystic tumors (seven cases) were characterized by the presence of multiple cystic spaces directly lined by tumor cells. Surgical resection was performed in all cases. Three patients had lymph node metastases at the time of diagnosis. One patient is dead with metastatic dissemination. The others are alive without recurrence or metastasis. The diagnosis of endocrine tumor must be considered for any pancreatic cyst discovered in a patient with a history of MEN1 syndrome or with clinical features suggestive of this syndrome. Cystic pancreatic endocrine tumors must be treated by surgical resection because of their possible malignant evolution.