Malignant Peripheral Nerve Sheath Tumor in Descending Colon: A Case Report

We report a unique case of malignant peripheral nerve sheath tumor (MPNST) of colon, not associated with neurofibromatosis or parasite infection. The tumor presented as an encircling mass in descending colon causing obstruction with nuberous metastatic lesions in a 43-year-old man. The tumor was largely composed of spindle cells which showed strong positivity for vimemtin, S-100 protein and Leu-7. The tumor often exhibited epithelioid feature where tumor cells were weakly positive for cytokeratin.