Clinicopathological analysis of low-grade papillary Schneiderian carcinoma: report of five new cases and review of the literature.

We report on five new cases of LGPSC, and confirm LGPSC as a new sinonasal carcinoma that behaves aggressively with metastatic potential. The combination of clinical behaviour and typical histological features can distinguish LGPSC from sinonasal papilloma and other carcinomas.