Table of Contents

Washington University Experience | NEOPLASMS (EMBRYONAL) | Medulloblastoma, Histologically Defined | Extensive Nodularity (MBEN) | 8B1 Medulloblastoma, desmoplastic (Case 8) H&E 4

8B1-7 This is a tumor composed of cells with little cytoplasm and a sheet-like growth pattern with rare rosette formation. The tumor cells also show minimal crowding and only occasional molding of the nuclei. The chromatin is finely speckled and nucleoli are inconspicuous. A few large nuclei are seen. The tumor is highly mitotically active and frequent apoptotic debris is seen scattered throughout the specimen. Among the sheets of monomorphic cells are islands of tumor cells with increased cytoplasm compared to the surrounding tumor and a lesser degree of mitotic activity. Within the pale islands are cells with a neurocytic look and occasional ganglion-like cells

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