Correlative study of squash smear cytology with histopathology in a rare case of anaplastic giant cell ependymoma of the pineal

Anaplastic giant cell ependymoma (AGCE) is a very rare neoplasm. Its cytological features, helpful for the intraoperative diagnosis, have been reported only once. AGCE is characterized by giant cells with intranuclear inclusions, besides other findings, observable in ependymal neoplasms, such as intracytoplasmic vacuoles, epithelial and glial features of the tumor cells and ependymal pseudorosettes. These findings can be detected also in intraoperative squash smear. Herein we describe a pineal AGCE, highlighting the cytological and histological correlations and underlining some useful diagnostic clues of this unusual entity.