Meningioma, neurilemmoma and astrocytoma specimens obtained with the squash method for cytodiagnosis. A cytologic and immunochemical study.

In this study, the peculiar cytomorphologic features of meningiomas and neurilemmomas were described in comparison with those of astrocytomas, employing squash preparations stained by the Papanicolaou method. The value of this method as an adjunct to rapid frozen diagnosis was demonstrated. Meningioma cells had common characteristic features in both cell clusters and individual cells; in the subclass of meningioma they also had peculiar features. Neurilemmomas of type A tissue of Antoni or of type B were characterized by the peculiar shapes of cell clusters and individual cells. In malignant meningiomas the cytologic features were pleomorphic, like those of metastatic carcinoma, making diagnosis difficult. By immunoperoxidase staining for vimentin, the characteristic differences in intracytoplasmic filaments of meningiomas and neurilemmomas could be shown more distinctly.