Brain Pathology Case of the Month - May 1997


Smear preparations at intraoperative consult during stereotactic biopsy showed that the tumor was composed of isomorphous cells containing round nuclei with fine "salt and pepper" chromatin. The background was composed of a fine fibrillary network in a mucinous matrix. Paraffin-embedded material of very small biopsy specimens showed that these cells were partially arranged as columnar structures. Also, two scattered ganglioid cells with vesicular nuclei were present. No mitotic figures or necroses were observed. Fine capillaries without endothelial hyperplasia or proliferation were moderate in amount. Bodian's silver impregnation demonstrated fine neuritic processes.

The microsurgically resected material was composed of several glassy specimens that, together, measured 1.5 cm in diameter. H&E stained sections demonstrated fascicles of small cells with round, uniform nuclei within a mucinous, microcystic matrix. Neurons of varying size scattered randomly and "floating" unaccompanied in the matrix are highlighted by immunohistochemistry for neurofilaments. A few particles contained areas with numerous Rosenthal fibers.


International Society of Neuropathology