Immunohistochemical localisation of macromolecules of the basement membrane and extracellular matrix of human gliomas and meningiomas.

The distribution of type I, III, IV and V collagen in 35 gliomas and 20 meningiomas was studied by indirect immunofluorescence staining. In addition, the presence of fibronectin (FN) and laminin (LN) is also reported. In gliomas expression of type IV collagen and LN was found in the vessel walls and associated with the endothelial glomerulus-like proliferations. FN and type V collagens were located in proliferating vessel walls in a pattern corresponding both to the basement membrane and the perivascular matrix around the vessels. In the extracellular matrix of grade III and IV gliomas occasional faint intercellular fluorescence was also observed with both FN and type V collagen. Type I and III collagens were localised in the vessel walls and in the perivascular connective sheet. Glioma cells did not express any of the antigens investigated. In meningiomas, type IV and V collagens, LN and FN were found in vessel walls, whorls formations and psammoma bodies. These stainings support the hypothesis of a vascular origin of these psammoma bodies which were only found in syncytial and transitional meningiomas. Both type I and III collagens were detected in the perivascular connective tissue. In general, meningioma cells and extracellular matrix did not express any of these molecules, except in transitional meningiomas where occasional fluorescence was observed in extracellular matrix with type V collagen and FN.