Carcinoid tumor presenting as a primary mesenteric mass: a case report and review of the literature.

We report a case of a primary carcinoid tumor arising in the mesentery of the small bowel of a 52-year-old man. The mesenteric mass in this patient was first identified as an incidental finding on CT imaging for bilateral nephrolithiasis. As a result of the abnormal findings, follow-up evaluation identified a partially calcified lobulated mesenteric lymph node. Diagnostic laparoscopy with lymph node sampling showed no evidence of hepatic or other metastatic disease. Pathologic analysis and immunohistochemistry of the mesenteric tissue revealed a malignant neuroendocrine tumor. Since all radiographic studies and subsequent workup revealed no evidence of other primary masses, this was determined to be a primary carcinoid tumor arising in the mesentery of the small bowel. Primary mesenteric carcinoid tumors are very rare because of their location of origin.