schwannoma (MONDO_0002546) is a benign, usually encapsulated slow growing tumor composed of Schwann cells. It affects peripheral and cranial nerves. It recurs infrequently and only rare cases associated with malignant transformation have been reported. Also known as: benign neurilemmoma, benign schwannoma, neurilemmoma, neurinoma, peripheral fibroblastoma, psammomatous schwannoma, schwannoma (WHO grade I), schwannoma, benign.