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.
Department of Pathology, Gunma University School of Medicine, Maebashi, Japan.
J
J
Hirato
Y
Y
Nakazato
A
A
Sasaki
M
M
Yokota
K
K
Nojiri
O
O
Toyoda
H
H
Nakajima
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