Aspiration cytology of solitary schwannoma.

The aspiration cytology of two cases of solitary schwannoma is documented. The first tumor was retroperitoneal and cystic; the aspirated fluid showed single, regular, spindle-shaped cells with cigar-shaped nuclei and scanty wavy cytoplasm in addition to lymphocytes and foamy histiocytes. The second tumor was solid and peripheral; its aspiration smears revealed spindle-shaped cells with cigar-shaped nuclei present singly or in clusters showing nuclei in a palisading pattern.