Sinonasal mucosal melanoma: 20-year experience at a tertiary referral center.

BACKGROUND: Sinonasal melanoma (SNM) is a rare cancer with extremely poor prognosis. Detecting melanoma on frozen section has historically been considered to be unreliable. A review of cases of sinonasal melanoma treated at a tertiary referral center was conducted to analyze treatment outcomes and identify prognostic factors for survival. In addition, an investigation was performed correlating sinonasal melanoma on frozen section and permanent analysis.
METHODS: An institutional review board-approved search of the pathology database for cases of primary sinonasal melanoma treated between 1991 and 2011 was performed. Fourteen cases were identified and the medical charts were reviewed.
RESULTS: Eleven patients had tumors arising from the nasal cavity, 2 arose from the maxillary sinus, and 1 from the ethmoid sinuses. Mean duration of follow-up was 20.7 (range, 1.4 to 84.5) months. Overall, 5-year recurrence-free survival and overall survival was 23% and 35%, respectively. All patients had surgical resection with intent for cure and all but 1 patient had adjuvant therapy. Survival analysis showed that positive margin status (log rank p = 0.031) and the presence of perineural/lymphovascular invasion (log rank p = 0.021) negatively affected recurrence-free survival and overall survival, respectively. Nine cases had evaluation of intraoperative frozen sections with 32 total sections submitted for analysis. When compared with final pathology, there was a 0% false negative rate.
CONCLUSION: Based on this series, positive margins and the presence of perineural/lymphovascular invasion are negative predictors of survival. In addition, intraoperative frozen section analysis of sinonasal mucosal melanoma correlates well with final pathology.