Brain Pathology Case of the Month - June 1999


The H&E sections show a tumor with a predominately papillary or filiform architecture (Figures 2 and 3). The cells are arranged in a pseudocolumnar fashion forming perivascular palisades about a fibrovascular core. There is marked nuclear pleomorphism with many bizarre nuclei, and a brisk mitotic rate (Figure 4), the nucleoli are indistinct. In areas, the papillary configuration gives way to patternless sheets of cells interrupted by zonal necrosis. Focally, the tumor cells surround microcavities which are either optically empty or contain "wisps" of eosinophilic fibrillary material. Confluent calcospherites are focally prominent. Vascular endothelial proliferation is present. Foci of glial frame indicate invasiveness. Rests of native plexus are occasionally encountered. Tumor cells stain intensely for LMW-CK (Figure 5) and EMA and focally for GFAP (Figure 6), S-100 protein and transthyretin (TTR) (Figure 7). The tumor does not stain with antibodies to CEA and CA125. Interestingly, the nuclei of over 60% of the tumor cells are positive for p53 immunolabel.


International Society of Neuropathology