Epithelioid schwannoma of the colon: Report of two cases

Schwannomas of the colon are rare tumors. Most of them are spindle cell tumors. The epithelioid variant is exceedingly rare with only 10 cases reported in the literature. We report two fortuitously discovered cases in 3 7 and 42-year-old women. The masses were located in the sigmoid and the right colon. They measured 2,5 and 3 cm in diameter. On microscopic examination, they were composed of sheets of uniform epithelioid cells without atypia or mitosis. One of them had a cuff of benign lymphoid hyperplasia. Immunohistochemical study showed positive staining of the tumor cells for S100 protein and some of them for glial fibrillary acidic protein. Some CD34-positive fibroblast-like cells were identified in the two tumors. There was no recurrence with a follow-up ranging from 6 to 24 months. Epithelioid schwannoma of the colon is a benign tumor of uncertain histogenesis which may be confused with more aggressive neoplasms.