Cellular Neurothekeoma

• Published in: Skin research Vol. 42; no. 2; pp. 200 - 204
• Main Authors: Nawate Noriko, Toyoda Masahiko, Nomoto Hiroo, Morohashi Masaaki, Kawaguchi Makoto, Wakaki Kunihiko, Nakamura Yohichi
• Format: Journal Article
• Language: Japanese
• Published: Meeting of Osaka Dermatological Association 2000; 日本皮膚科学会大阪地方会
• Subjects: cellular neurothekeoma; immunohistochemistry; nerve sheath myxoma; neurothekeoma; 富細胞性神経莢腫
• ISSN: 0018-1390; 1884-541X
• DOI: 10.11340/skinresearch1959.42.200

We report a case of cellular neurothekeoma occurring in a 28-year-old Japanese male. Histopathologically, the neoplasm was composed of scattered small nests, which were surrounded by collagen bundles, in the dermis. Tumor cells were epithelioid or spindle-shaped, and had eosinophilic cytoplasm. A small amount of mucin matrix was seen around each tumor nest. Immunohistochemical examination revealed that the tumor cells were positive with α-smooth muscle actin, vimentin, neuron specific enolase, human prolyl 4-hydroxylase, S-100 protein and epithelial membrane antigen. Cellular neurothekeoma has been recognized as a variant of nerve sheath myxoma, namely myxoid type of neurothekeoma. However, our immunohistochemical results differed from those of myxoid type of this tumor previously reported, and suggest that cellular neurothekeoma is an unusual benign cutaneous tumor of mixed lines of differentiation including neuroendocrin, smooth muscular, fibroblastic and myofibroblastic differentiation. 28歳男性の上背部に生じた有痛性腫瘤で組織学的にcellular neurothekeoma (富細胞性神経莢腫) の特徴を示した症例を報告した。すなわち真皮上層から皮下組織直上に存在する比較的境界明瞭な島状配列を持つ腫瘍胞巣から成り, 各胞巣内は細胞密度が高く, 腫瘍細胞は明るい胞体と円形-楕円形の核を有していた。Alcian blue染色にて腫瘍胞巣辺縁にムチンの存在が確認された。免疫組織化学的には, 腫瘍細胞はα-SMA, vimentin, human prolyl 4-hydroxylase, NSE, EMA, S-100蛋白に陽性を示した。自験例のcellular neurothekeomaは神経系細胞への分化に加え平滑筋細胞, 線維芽細胞, 筋線維芽細胞などへの多分化傾向を有していることが示唆された。