Glial fibrillary acidic protein in medulloblastomas

Abstract

Two cases of medulloblastoma are described which show positive immunostaining for glial fibrillary acidic protein (GFAP) in many cells. The surgical and autopsy specimens were examined by the indirect immunoperoxidase method. Positive staining for GFAP was demonstrated in the small, round to polygonal cells in both surgical specimens and in the small spindle cells in the autopsy specimen of one case. In the small, round to polygonal cells positive GFAP was shown as a perinuclear brown rim or intracytoplasmic brown droplet. In the small spindle cells, the cytoplasm and the polar processes were stained. Except for GFAP staining, these positive cells were morphologically indistinguishable from the accompanying unstained cells, indicating that GFAP was expressed in the medulloblastoma cells. Considering that GFAP is specific for astrocytes, these findings suggest the potential of astrocytic differentiation in the neoplastic cells of these medulloblastomas. The findings obtained in other 28 medulloblastomas examined in parallel are also discussed briefly.

Gender Effect in Experimental Models of Human Medulloblastoma: Does the Estrogen Receptor β Signaling Play a Role?

“…Consistent with these data, we observed a more differentiated phenotype, with significantly reduced malignancy, in tumors from females, as shown by a decreased stem cell population (nestin has been identified as a stem like cell marker for medulloblastoma) [42] and a substantial increase of neuronal (NSE) and glial (GFAP) differentiation markers. In this respect, our results are in line with previous findings observed in some human specimens showing that medulloblastomas have a capacity of differentiation along neuronal and glial lines [43]–[45].…”

Diagnostic markers in paediatric medulloblastoma: a Paediatric Oncology Group Study

“…The demonstration, by immunoperoxidase, of GFAP in a small proportion of tumour cells has been confirmed in various general studies on the immunoreactivity of gliomas for the protein, including those by Deck et al, Eng [1][2][3][4][5][6][7] The view that none of the GFAP-positive cells in medulloblastomas is likely to be neoplastic 45,46 can be countered by the finding of GFAP-positive medulloblastoma cells infiltrating the cerebellar subarachnoid space, and by the occasional positivity of medulloblastoma cells permeating the bone marrow when extraneural dissemination has occurred. 47 The immunohistochemical studies by Herpers [48][49][50][51][52][53][54][55] have further documented the immunopositivity of some of the tumour cells for GFAP. The tumour cells immunoreactive for GFAP in this study revealed reactivity within the cytoplasmic extensions that trailed off to one side as unipolar extensions or populated the nodules.…”

Cytology of Desmoplastic Medulloblastoma in Imprint Smears

“…Glial fibrillary acidic protein-reactive cells can be identified in the pale, nodular regions. 5,9,11 Cells positive for cytoplasmic markers of more restricted neuronal distribution are also found in these islands; that suggests that these pale zones are organized foci of divergent astroglial as well as neuronal growth. 3,7,8 The cytologic findings in other subtypes of medulloblastoma have been well described.…”