Malignant peripheral nerve sheath tumor of the colon in a patient with von Recklinghausen's disease: report of a case.

Malignant peripheral nerve sheath tumor (MPNST) arising from the colon is an extremely rare clinical entity. We report one such case of an adult female with neurofibromatosis type I who presented with pain and a lump in her abdomen. A computed tomographic scan revealed a 10 × 8-cm mass in the splenic flexure of her colon that was compressing its lumen, but the results of a colonoscopy were normal. Segmental resection of the left colon was performed based on the clinical possibility of gastrointestinal stromal tumor. However, on histopathological examination and immunohistochemical staining, the final diagnosis came out to be MPNST. This case highlights that, although rare, the possibility of MPNST should be considered when dealing with extramucosal colonic wall tumors.