Background Accurate forecasting of the risk of death is crucial for people living with head and neck mucosal melanoma (HNMM). We aimed to establish and validate an effective prognostic nomogram for HNMM. Methods Patients with HNMM who underwent surgery between 2010 and 2015 were selected from the Surveillance, Epidemiology, and End Results (SEER) database for model construction. After eliminating invalid and missing clinical information, 288 patients were ultimately identified and randomly divided into a training cohort (199 cases) and a validation cohort (54 cases). Univariate and multivariate Cox proportional hazards regression analyses were performed in the training cohort to identify prognostic variables. Independent influencing factors were used to build the model. Through internal verification (training cohort) and external verification (validation cohort), the concordance indexes (C-indexes) and calibration curves were used to evaluate the predictive value of the nomogram. Results For the training cohort, five independent risk predictors, namely age, location, T stage, N stage, and surgery, were selected, and nomograms with estimated 1- and 3-year overall survival (OS) and cancer-specific survival (CSS) were established. The C-index showed that the predictive performance of the nomogram was better than that of the TNM staging system and was internally verified (through the training queue: OS: 0.764 vs 0.683, CSS: 0.783 vs 0.705) and externally verified (through the verification queue: OS: 0.808 vs 0.644, CSS: 0.823 vs 0.648). The calibration curves also showed good agreement between the prediction based on the nomogram and the observed survival rate. Conclusion The nomogram prediction model can more accurately predict the prognosis of HNMM patients than the traditional TNM staging system and may be beneficial for guiding clinical treatment.

<b><i>Introduction:</i></b> The aim of this study was to summarize the incidence, risk factors, and prognostic factors of distant metastasis of sinonasal carcinoma. <b><i>Methods:</i></b> We collected data for patients diagnosed with sinonasal carcinoma from 2010 to 2015 from the SEER database and analyzed the risk factors for distant metastasis via univariate and multivariate logistic regression analysis. In addition, univariate and multivariate Cox regression analysis models were used to describe the factors related to the overall survival of patients with distant metastasis. <b><i>Results:</i></b> A total of 2,255 patients were included in the study, including 86 in the distant metastasis group and 2,169 in the nondistant metastasis group. In the univariate and multivariate logistic regression analyses, we found that the risk factors affecting distant metastasis were poorly differentiated tumor grade (HR = 1.932, 95% CI: 1.082–3.452, <i>p</i> = 0.026), advanced T stage (T3–T4) (HR = 4.302, 95% CI: 2.047–9.039, <i>p</i> &#x3c; 0.001), and advanced N stage (HR = 3.093, 95% CI: 1.911–5.005, <i>p</i> &#x3c; 0.001). Moreover, elderly patients had a poorer prognosis than young patients (HR = 1.792, 95% CI: 1.096–2.931, <i>p</i> = 0.02) and that surgical treatment improved the survival rate of tumor patients with distant metastasis (HR = 0.450, 95% CI: 0.247–0.821, <i>p</i> = 0.009). <b><i>Conclusion:</i></b> Tumor grade, T stage, and N stage are risk factors for distant metastasis in sinonasal carcinoma, while an age of less than 65 years and surgery were positive prognostic factors for sinonasal carcinoma patients with distant metastasis.