Low CM, Price DL, Moore EJ, et al. - This is the first population-based analysis identifying nodal disease at presentation as a negative prognostic factor for overall survival (OS) and disease-specific survival (DSS) in sinonasal mucosal melanoma (SNMM) patients. Three hundred twenty-eight cases of SNMM have been identified. The nasal cavity in 279 patients was the most frequent sinonasal anatomic location followed by the maxillary sinus in 60 patients. Data reported that 5-year OS was 22.7% and 5-year DSS was 26.8%. As negative predictors of OS and DSS, the presence of positive nodes at diagnosis, distant metastases at diagnosis, primary tumor site, and increased age was found to be significant. SNMM is a rare, poorly prognosed pathologic entity. Negative prognostic factors in OS and DSS are the presence of nodal and distant metastases at the diagnosis. Such factors can be used in developing new risk stratification models and in informing treatment strategies and patterns of surveillance.