Sinonasal Melanoma: A Single-Institution Analysis and Future Directions

Background Sinonasal melanoma is a rare disease entity with a high mortality rate ranging from 6.5 to 34% 5-year overall survival. The surgical management paradigm has significantly changed over the past decade with the introduction of expanded endonasal techniques. These techniques have been shown to decrease complication rates without compromising survival outcomes. There have also been advances in the management of metastatic and locally advanced disease with immunotherapy. These novel medications provide hope for improved survival outcomes in patients with metastatic sinonasal melanoma.

Methods Single-institution retrospective review of all adult patients with sinonasal melanoma, surgically managed by two otolaryngologists at the University of Michigan over a 9-year period. Thirty-one patients met the inclusion criteria. Parameters that affect survival were analyzed using Cox proportional hazard models, and survival outcomes were analyzed with the Kaplan–Meier method. We also reviewed three cases of immunotherapy administered in the setting of distant metastatic disease.

Results Most patients were older than 60 years (81%), Caucasian (93%), and female (71%). Most tumors originated from the nasal cavity (74%) and were stage III at diagnosis (61%). The most common presenting symptoms were epistaxis (87%) and nasal obstruction (55%). Most patients were managed endoscopically (67%), the majority of which had stage III disease (71%). Even advanced-staged tumors were managed endoscopically, with 57% of our stage IVB tumors being managed solely by endoscopic techniques. Twenty-two pathology specimens were available for additional analysis. Adverse features such as perineural and angiolymphatic invasion and satellitosis were rare. Necrosis was present in 41%, and ulceration in 64%, whereas pigmentation was absent in 55% of cases. Factors statistically associated with decreased overall and distant metastasis-free survival were stage and tumor origin within the nasal cavity. The 2-year overall survival for all stages was 77% with 95% CI [56%, 89%]. By stage, the 2-year overall survival was 87% with 95% CI [58%, 97%], 67% [5%, 95%] and 57% [17%, 84%] for stages III, IVA, and IVB, respectively. Two-year locoregional control was 72% with 95% CI [62%, 97%], 100% [no local recurrences], and 38% [1%, 81%] for stages III, IVA, and IVB, respectively. The 2-year distant control was 89% with 95% CI [62%, 97%], 33% [1%, 77%], and 21% [1%, 60%] for stages III, IVA, and IVB. Our three patients undergoing immunotherapy all had stage 4 disease at diagnosis with development of distant disease within 1 month to 4 years of surgical resection. Two of the three remain alive with stable disease at 2 to 4 years of treatment.

Conclusion Treatment of sinonasal melanoma has drastically changed over the past decade. Our review revealed an excellent 2-year overall survival for patients with stage III disease with an appreciable decline in survival with more advanced disease. Advanced stage and tumor origin within the nasal cavity compared with the paranasal sinuses are predictors of poor outcome. Endoscopic techniques can be used successfully alone, or in combination with open techniques, in all stages of disease, though morbidity must be a consideration, especially in light of newer therapeutic strategies.

No conflict of interest has been declared by the author(s).