Case of cystic schwannoma.

Schwannoma is a well-defined tumor arising from the nerve sheath. It may present as a solitary mass in any part of the body, but is more commonly seen in the head, neck and extremities. We describe a 32-year-old female patient with a small dermal nodule on the forehead, which was 2 cm in diameter, round and of a cystic nature. Microscopic examination revealed that it consisted of compact spindle cells arranged partly in short bundles or a fascicular pattern with outstanding cystic degeneration manifested as a large, unilocular cavity in the center of the tumor tissue. The tumor cells were positive for S-100 protein and negative for epithelial membrane antigen (EMA), while the tumor capsule was positive for EMA. There was no S-100-positive membrane-like structure lining the cyst wall.