A clinicopathological study of sinonasal neuroendocrine carcinoma and sinonasal undifferentiated carcinoma

Objective: Sinonasal undifferentiated carcinoma (SNUC) and sinonasal neuroe ndocrine carcinoma (SNEC) are relatively newly recognized, rare entities re quiring further clinicopathological analysis to advance our understanding a nd determine prognostic distinctions between them. Study Design: Retrospect ive chart review. Methods: Cases were retrieved from the Copath system. One patient was seen in consultation from an outside institution. Histological and immunohistochemical findings, patient demographics, treatment regimens , and outcomes were analyzed and compared. Results: Ten patients (7 men, 3 women) ranging in age from 17 to 58 years (mean age, 44.7 y) were included. Four patients were classified with SNEC, six as having SNUC. The predomina nt site was the superior nasal cavity or ethmoids (seven cases), followed b y the maxilla (four cases). Disease in four patients was clinically staged as N1 (three with SNUC, one with SNEC), and in six patients as NO (three wi th SNEC, three with SNUG). Of the nine patients who were treated initially with surgical resection, seven received postoperative radiation therapy alo ne, one received postoperative radiation and chemotherapy, and one had only limited postoperative chemotherapy. One patient was treated with radiation therapy and chemotherapy alone, without surgical resection. Follow-up was obtained ranging from 6 to 108 months (mean period, 26.4 mo). Three patient s died of disease 10, 14, and 41 months, respectively, after diagnosis. Thr ee patients had persistent disease at 6, 9, and 21 months, respectively, tw o of them with distant metastases. Four patients were disease free after 6, 18, 31, and 108 months, respectively. Conclusions: SNUG and SNEC are both aggressive tumors, usually presenting in middle age as a nasal mass. Both t umors have the capacity to metastasize locally and distantly, and both can result in poor outcomes. This small series precludes a demographic or progn ostic distinction between the two groups.