Squash cytology of subependymal giant cell astrocytoma: report of four cases with brief review of literature.

Squash cytology description of subependymal giant cell astrocytoma (SEGA) is poorly described in the literature. Objective of this study is to study the cytomorphological features of SEGA in squash smears. Introperative squash smear preparations of four patients of SEGA diagnosed from 2004 to 2010 were reviewed. One to two millimetres of the biopsy material was crushed between two glass slides to make a thin film and fixed in 95% alcohol and stained by haematoxylin and eosin (H&E). Smear cytology diagnoses were correlated with clinical, radiological data and finally with histopathological findings of the tumor specimen. We had four cases (all males; age range 11-15 years; mean age 12.5 years). All tumors were located in the lateral ventricles. The cytological smears in all four cases were cellular and display pleomorohic binucleate to multinucleate tumor cells disposed in cohesive clusters, groups or lying singly. Elongated spindle shaped and strap cells with long thick cell processes were also identified. On squash smears, SEGA can be diagnosed when cytomorphological features are correlated with clinical and radiological finding. The distinct cytomorphological features are cellular smears comprising of pleomorohic binucleate to multinucleate tumor cells with round to polygonal eccentrically placed mildly anisomorphic nuclei, prominent nucleoli, and abundant eosinophilic glassy cytoplasm. Astrocytic fibrillary background, endothelial proliferation, mitosis, and necrosis are lacking.