Small round-cell tumors can arise from several anatomic sites in children and adults, and their primary diagnosis and clinical course often present challenges to physicians. We present a case of a rare adult-onset round-cell tumor, esthesioneuroblastoma, of nasal epithelial origin, which spread into the brain and subsequently to cervical lymph nodes. The report describes how fine-needle aspiration cytology identified the metastatic spread and contributed to its clinical management. The use of ancillary procedures in differential diagnosis of small round-cell tumors is reviewed.