Malignant schwannoma in a case of type 1 neurofibromatosis with decreased immunoreactivity of smooth muscle α-actin in tumor vessels

• Published in: Journal of dermatological science Vol. 8; no. 2; pp. 157 - 161
• Main Authors: Inoue, Mitsuse, Nakayama, Juichiro, Urabe, Atsumichi, Taniguchi, Shun'ichiro, Kuroki, Rie, Hori, Yoshiaki
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ireland Ltd 01.10.1994
• Subjects: Actins - metabolism; Adult; Humans; Immunohistochemistry; Male; Malignant schwannoma; Muscle, Smooth, Vascular - metabolism; Neurilemmoma - complications; Neurilemmoma - metabolism; Neurofibromatosis; Neurofibromatosis 1 - complications; Platelet-Derived Growth Factor - metabolism; Smooth muscle α-actin; Smooth muscle α-actin; Malignant schwannoma; Neurofibromatosis
• ISSN: 0923-1811; 1873-569X
• DOI: 10.1016/0923-1811(94)90011-6

A malignant schwannoma in the left calf of a 37-year-old man with type 1 neurofibromatosis is herein reported. Since it is known that capillaries in benign neurofibromas are accompanied by hypertrophic pericytes expressing an abundant amount of smooth muscle α-actin (SMAA), we examined the immuohistochemical reactivity of SMAA within this malignant tumor and then compared it with that in surrounding benign areas. In the nests of malignant cells, decreased SMAA staining was found in the capillary walls. In the benign tissues around the malignant tumor, various extents of SMAA could be visualized in the vessels and myofibroblasts. Platelet-derived growth factor (PDGF) was also detected in the tumor, suggesting that cytokines secreted by malignant cells may have an influence on the expression of SMAA as well as on the alteration of the structure of blood vessels.