Vessel Morphologies of the Brain in Cytological Squash Preparations Are Useful for Intraoperative Diagnosis of High-Grade Astrocytomas

Abstract

Objective: The aim of this study was to determine whether intraoperative cytological evaluation of squash preparations is of benefit for differentiating high-grade from low-grade astrocytomas. Methods: Squash preparations of 42 astrocytomas were classified histologically according to the World Health Organization (WHO) 2007 classification system as grade II (n = 12), grade III (n = 11), and grade IV (n = 19) and were divided into 2 groups, namely a low-grade group (grade II) and a high-grade group (grades III and IV). The focus was on morphological cell and vessel characteristics, namely nuclear atypia, chromatin pattern, nuclear enlargement, variation in nuclear size, the presence of nucleoli, mitosis, tumor necrosis, cell density, multibranched vessels, and vascular dilatation, and these characteristics were compared between the low- and high-grade groups. Results: Nuclear atypia, the presence of coarse chromatin, variations in nuclear size, and cell density ≥200 per high-power field were significantly more prevalent in high- than in low-grade astrocytomas (p = 0.0407, p < 0.01, p < 0.01, and p < 0.01, respectively). Vessels with > 3 branches and a mean vessel diameter ≥20 μm were more prevalent in high- than in low-grade astrocytomas (p < 0.01). Conclusion: Squash preparation cytology provides added benefit for the intraoperative identification of high-grade astrocytoma.