Stromal cells in cerebellar haemangioblastomas: an immunocytochemical study

The nature of the stromal cells in formalin-fixed paraffin-embedded material from 23 cerebellar haemangioblastomas was investigated using antisera to intermediate filaments (glial fibrillary acidic protein, vimentin and desmin), histiocytic markers (alpha 1-antitrypsin, alpha 1-antichymotrypsin and lysozyme), glycolytic enzymes (alpha and gamma enolase and aldolase C4) and the endothelial markers, factor VIII related antigen and Ulex europaeus I lectin. Most stromal cells stained positively for vimentin and the glycolytic enzymes. Occasional process-bearing cells within the stroma stained strongly for glial fibrillary acidic protein, alpha 1-antitrypsin and alpha 1-antichymotrypsin. No stromal cell staining for desmin, lysozyme or the endothelial markers was observed, although the latter stained the vascular endothelium within all neoplasms. The findings do not support previous suggestions of an endothelial or histiocytic origin for the stromal cells. They appear to be a heterogeneous population including entrapped reactive astrocytes and locally-derived non-angiogenic cells of neuroectodermal (pial) origin.