Angiocentric glioma: presentation of two cases with dissimilar histology

Abstract

Angiocentric glioma (AG) is a recently described tumor of the brain which was included as a distinct entity in the 2007 WHO classification. To date only 26 cases have been reported in the literature. We describe two additional cases of this possibly confusing lesion of the brain. Emphasis is put on variations in the histopathological picture. The patients (20- and 55-year-old males) presented with seizures and headaches, respectively. Imaging examination showed a small cortical-subcortical tumor in each case. Both tumors were totally removed. Paraffin blocks from the two cases were examined with classical histopathology stainings and immunohistochemistry for GFAP, vimentin, EMA, neurofilament protein, synaptophysin, S100 protein, CD31, CD34, FVIII, smooth muscle actin and Ki67. The tumor proliferation was restricted around small intraparenchymal vessels. Immunohistochemistry demonstrated positivity for glial and negativity for vascular or neuronal markers. The cell shape and arrangement was different in the two cases. AG is a peculiar tumor of uncertain histogenesis but with certain glial reactivity. Histopathology is variable but restricted, for unknown reasons, to perivascular areas. Apparently, a better prognosis than for other gliomas is distinctive. Further studies are needed in order to expand the information regarding the clinical behavior and therapeutic approach of this tumor type.