T Yamamoto1, R Minami, C Ohbayashi. 1. Department of Orthopaedic Surgery, Kobe University School of Medicine, Kobe, Japan. yamatetu@med.kobe-u.ac.jp
Abstract
BACKGROUND: Malignant epithelioid schwannoma is a rare tumor. The aim of this study is to describe a case of subcutaneous malignant epithelioid schwannoma with cartilaginous differentiation. METHODS: Histological, immunohistochemical, and ultrastructural examinations were performed on a tumor that arose on the back of a 37-year-old woman. RESULTS: Histologically, the tumor predominantly consisted of small, round or polygonal cells arranged in cords or nests. Immunohistochemical study revealed that the tumors cells were positive for vimentin, S-100 protein, glial fibrillary acidic protein and neuron specific enolase. The cells were negative for HMB-45, keratin, epithelial membrane antigen, and CAM5.2. Electron microscopic study showed closely associated cells with undifferentiated features. The cells were devoid of external laminae and cellular junctions. CONCLUSION: Malignant epithelioid schwannoma should be pathologically differentiated from other epithelioid tumors with cartilaginous elements.
BACKGROUND:Malignant epithelioid schwannoma is a rare tumor. The aim of this study is to describe a case of subcutaneous malignant epithelioid schwannoma with cartilaginous differentiation. METHODS: Histological, immunohistochemical, and ultrastructural examinations were performed on a tumor that arose on the back of a 37-year-old woman. RESULTS: Histologically, the tumor predominantly consisted of small, round or polygonal cells arranged in cords or nests. Immunohistochemical study revealed that the tumors cells were positive for vimentin, S-100 protein, glial fibrillary acidic protein and neuron specific enolase. The cells were negative for HMB-45, keratin, epithelial membrane antigen, and CAM5.2. Electron microscopic study showed closely associated cells with undifferentiated features. The cells were devoid of external laminae and cellular junctions. CONCLUSION:Malignant epithelioid schwannoma should be pathologically differentiated from other epithelioid tumors with cartilaginous elements.