Primitive Neuroectodermal Tumor Arising in the Colon: Report of a Case

Abstract

Peripheral primitive neuroectodermal tumors (pPNETs) are usually found in the soft tissue of the extremities, paravertebral region, and chest wall. We report a rare case of a pPNET arising in the colon. A 59-year-old man underwent left hemicolectomy for an infiltrative ulcerating tumor, 11 cm long, in the descending colon. Histological examination of the resected specimen revealed small, round cell proliferation with rosette-like structures, and confirmed regional lymph node involvement and peritoneal dissemination near the primary tumor. Immunohistochemically, the tumor cells were positive for synaptophysin and MIC2 (CD 99). ESW-FLI1 chimeric mRNA was detected in the tumor by reverse transcriptase-polymerase chain reaction. The patient underwent resection of recurrence in the retroperitoneum 3 months later, but metastasis rapidly developed and he died of the disease 7 months after his first operation.

Radiological features of primitive neuroectodermal tumors in intra-abdominal and retroperitoneal regions: A series of 18 cases

“…According to previous reports, pPNETs arising in hollow organs (such as the colon and bladder) usually present as local wall thickening [16,17], as were the two cases in the present study. In addition, scattered punctuate calcification was found in the patient with bladder PNET, surrounding tissue invasion was observed in both cases, and distant metastasis was observed in the colon PNET patient.…”