A Case of Peripheral Primitive Neuroectodermal Tumor Arising in the Small Intestine

Shinzo Ozaki, Shinya Yamamoto, Akihiro Kawamura¹⁾, Keijiro Araki²⁾ and Makoto Hiroi³⁾

Department of Surgery, Kubokawa Hospital¹⁾
First Department of Surgery, Kochi Medical School²⁾
Department of Clinical Laboratoy, National Kochi Hospital³⁾

Peripheral primitive neuroectodermal tumor (PNET) is an extracranial primitive small round cell tumor showing histological, immunohistochemical, or electron microscopic evidence of neuroectodermal differentiation. It is common in soft tissue and bone in children and young adults. We report an unusual case of a PNET arising in the small intestine. A 49-year-old man admitted for lower abdominal pain was found to have multiple niveau in plain X-ray of the abdomen, and a history of acute pancreatitis surgery suggested adhesional ileus. He was treated conservatively with a long tube, but symptoms were not ameliorated. Computed tomography showed invagination of the small intestine, necessitating surgery. Laparotomy showed 14 white tumors arising in the small intestine, and the tumor on the most anal side showed invagination. We undertook radical resection and partial resection invaginated tumor. Microscopic examination showed a small round cell tumor. Immunohistochemically, tumor cells were positive for MIC2 protein. After surgery, ileus improved, but the patient died 41 days later. To the best of our knowledge, this is the first case in the literature of PNET arising in the gastrointestinal tract.

Key words
primitive neuroectodermal tumor, ewing sarcoma, MIC2

Reprint requests
Shinzo Ozaki Department or Surgery, Hata Kenmin Hospital
3-1 Yoshina, Yamana-cho, Sukumo-shi, 787-0785 JAPAN

Accepted
October 29, 2003

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