malignant gastrointestinal neuroectodermal tumor: a case report and literature review

Introduction: the gastrointestinal neuroectodermal tumor (gnet) is a rare mesenchymal tumor mainly arising in the gastrointestinal tract. case presentation: herein, we describe a case of gnet that had been previously diagnosed as metastatic primitive neuroectodermal tumor (pnet) to the lung and liver and received 30 cycles of adjuvant chemotherapy. the physical exam showed a palpable mass in the lower right quadrant of the abdomen. the tumor mass was composed of diffuse sheets of epithelioid tumor cells, in which osteoclast-like giant cells scattered unevenly. immunohistochemically, the tumor cells were diffusely positive for sox10, cd99, and cd56, patchy positive for pan-ck, and negative for desmin, hmb-45, melan-a, and chromogranin. conclusions: consistent with previous studies that reported a secondary gnet following chemotherapy, we assume that the chemotherapy might trigger the tumorigenesis of gnet in this case.