Malignant Transformation of Schwannoma to S-100 Negative Epithelioid Malignant Peripheral Nerve Sheath Tumor: A Case Report. - Shirai Y; Matsuoka M; Okawa H; Miyazaki T; Hashimoto T; Onodera T; Hasegawa T; Matsuno Y; Iwasaki N (International journal of surgical pathology, 2026)