Intracranial malignant fibrous histiocytoma: characterization of GFAP-positive cells in the tumor.
A case of malignant fibrous histiocytoma (MFH) arising in the cerebellopontine angle of a 57-year-old woman was reported. The immunohistochemical and electron microscopic findings indicated distinct fibrohistiocytic nature and myofibroblastic differentiation of this peculiar tumor. Immunohistochemistry disclosed that the tumor cells expressed monocyte/macrophage markers including CD-68, MAC 387, and alpha-1-antichymotrypsin. In addition, the neoplasm contained scattered glial fibrillary acidic protein (GFAP)-positive cells which made small nests in some areas. These GFAP-positive cells had bundles of densely packed intermediate filaments and scanty organellae in the cytoplasm, as demonstrated by an immunostained-semithin and serial-ultrathin section method. By immunostaining of MIB-1 and GFAP, and silver nucleolar organizer region (AgNOR) impregnation on serial sections, the GFAP-positive cells were not labeled by MIB-1 and their AgNOR counts averaged 1.13/nucleus. Thus, these GFAP-positive cells seem to have lower proliferating activity than neoplastic astrocytes. It is concluded that they may be nonneoplastic astrocytic cells involved by MFH.
Hirato
J
J
Department of Pathology, Gunma University School of Medicine, Maebashi, Japan.
Nakazato
Y
Y
Sasaki
A
A
Yokota
M
M
Nojiri
K
K
Toyoda
O
O
Nakajima
H
H
D001932:Brain Neoplasms / Q000648:ultrastructure*; D002530:Cerebellopontine Angle / Q000648:ultrastructure*; D005260:Female; D005904:Glial Fibrillary Acidic Protein; D018219:Histiocytoma, Benign Fibrous / Q000648:ultrastructure*; D006801:Humans; D008854:Microscopy, Electron; D008875:Middle Aged
D005904:Glial Fibrillary Acidic Protein