Malignant schwannoma in a case of type 1 neurofibromatosis with decreased immunoreactivity of smooth muscle alpha-actin in tumor vessels.
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 alpha-actin (SMAA), we examined the immunohistochemical 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.
Department of Dermatology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
M
M
Inoue
J
J
Nakayama
A
A
Urabe
S
S
Taniguchi
R
R
Kuroki
Y
Y
Hori
D000199:Actins / Q000378:metabolism*; D000328:Adult; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009442:Neurilemmoma / Q000150:complications* / Q000378:metabolism*; D009456:Neurofibromatosis 1 / Q000150:complications*; D010982:Platelet-Derived Growth Factor / Q000378:metabolism
D000199:Actins; D010982:Platelet-Derived Growth Factor