Fine-needle aspiration cytology of "ancient" schwannoma

The term "ancient" schwannoma was proposed for a group Of neural tumors sho wing degenerative changes and marked nuclear atypia. Prior to the realizati on that the observed atypia was a regressive phenomenon, many of these lesi ons were erroneously diagnosed as sarcomas. Fine-needle aspiration (FNA) cy tologic material from five patients is included in this study. Tissue exami ned histologically included Soul resected tumors and 18 gauge core biopsies of one tumor: Aspirates of ancient schwannoma showed many of the same feat ures as FNA of regular schwannoma: aggregates of spindled cells with indist inct cytoplasm and elongate nuclei with blunt point ends. The feature uniqu e to these lesions was nuclear pleomorphism, which was identified in all as pirates. Nuclear inclusions were identified in all but one case. Cystic deg eneration, xanthomatous changes, and perivascular sclerosis were identified in excised lesions. Ancient schwannomas show most of the FNA features of b enign schwannomas but can demonstrate marked nuclear atypia. The FNA featur es of ancient schwannoma are important to note because of the potential to confuse this lesion with a more serious one such as sarcoma on FNA. Diagn. Cytopathol. 1999;20:307-311. (C) 1999 Wiley-Liss, Inc.