Nuclear grooves in ependymoma. Cytologic study of 21 cases

To study the efficacy of crush preparation smears in the diagnosis of ependymomas. The study group consisted of 21 patients aged 7-61 years. All were admitted to Shiraz University hospitals (Nemazi and Beheshti) with intramedullary tumors. Fourteen were ventricular (fourth ventricle), 1 was in the parietal lobe, 5 were in the lumbosacral region and 1 was in the cauda equina. Intraoperative crush preparation smears were obtained from tissue, which was sent for frozen section and diagnosed cytologically. The control group consisted of 123 intracranial tumors (meningiomas, schwannomas, astrocytomas, oligodendrogliomas, medulloblastomas, pituitary adenomas, choroid plexus papilloma, craniopharyngioma and metastatic tumors). The smears in 11 cases revealed perivascular pseudorosettes, and the smears in 21 cases revealed ependymal rosettes. Papillary clusters, calcification and intranuclear inclusions were seen in two cases. Acinar structures were seen in seven cases. Myxomatous material was seen in one case. Nuclear grooves were seen in 15 cases. All cases were diagnosed as ependymomas. Biopsy specimens confirmed the cytologic diagnosis. The tumors in the control group showed no evidence of nuclear grooves. Fifteen cases of ependymoma showed a substantial number of nuclear grooves. Intraoperative crush preparation smears were very useful in the diagnosis of ependymomas and helped with the rapid interpretation of frozen sections.