Distribution of collagen type IV in brain tumors: an immunohistochemical study.

One hundred-twenty seven human brain tumors were examined by an immunoperoxidase technique for the expression of collagen Type IV, a major constituent of basement membrane. The parenchymal components were negative for the marker protein in all tumors except for neurilemmomas which were positively stained. In every case, the antibody to collagen Type IV showed distinct staining of the vascular pattern. In gliomas, capillaries increased in number and the vascular staining increased in intensity. Fine branching capillaries and endothelial glomeruloid proliferations characteristic each of oligodendrogliomas and glioblastomas could be distinctly illustrated. In two ependymomas, marked capillary proliferation was noted in periventricular areas. Fibrillar staining was observed between the tumor cells in seven of 34 meningiomas. Pericapillary lamellar deposition of collagen Type IV suggests a vascular origin of psammoma bodies. In some malignant tumors, pial-glial membranes were disrupted and the Virchow-Robin spaces were filled with malignant cells. Collagen Type IV was absent around the stromal cells of hemangioblastomas, suggesting that these stromal cells were unrelated histogenetically with endothelial cells. Collage Type IV may be useful in the differential diagnosis between meningiomas and neurilemmomas.