A case of peripheral primitive neuroectodermal tumor of retroperitoneal origin

Abstract

Surgery was performed on a 43-year-old man who was referred to our department by a local physician for further examination and treatment after being diagnosed with a right adrenal tumor on abdominal ultrasound during a medical checkup. A tumor of retroperitoneal origin was diagnosed intraoperatively and resected. On histopathological examination, Homer-Wright rosettes were observed, and because the tumor was MIC2-positive on immunostaining, it was diagnosed as a peripheral primitive neuroectodermal tumor (PNET). Despite adjuvant chemotherapy, the patient died of the tumor approximately two years and seven months postoperatively. PNET is a small round cell tumor that develops outside the central nervous system and differentiates into neuroepithelium histologically, immunologically, and ultrastructurally. It often develops in the limbs and chest wall, and it rarely occurs in the abdomen. A case of PNET thought to be of retroperitoneal origin is reported and the relevant literature reviewed.