Sinonasal Malignant Melanoma.

ABSTRACT

Sinonasal malignant mucosal melanoma (SNMM) is a rare, aggressive, and capricious tumour accounting for 4% of sinonasal malignancies. Recent studies suggest an increasing frequency. There are few large published series, but all authors report poor outcomes irrespective of treatment of approximately 25% 5-year survival. As a consequence, the American Joint Committee on Cancer (AJCC) have restaged all SNMMs as T3 or greater, irrespective of extent. Surgery remains the principle treatment modality. Survival and recurrence data analysis from a single-centre prospective cohort of 125 cases (all treated surgically with or without radiotherapy) showed 5-year overall survival was 28% and disease-free survival was 23.7%. Local control was achieved for a median of 21 months, with a 5-year disease control rate of 27.7%. However, endoscopically resected cases showed a significant overall survival advantage up to 5 years, confirming that endoscopic resection of SNMM does not adversely affect outcome and may even be beneficial up to 5 years. These findings are supported by other recent series in the literature. Radiotherapy did not improve local control or survival in this study, though there is debate in the literature as to its value. Cervical metastases confer a dramatically worse outcome. Chemotherapy has not previously shown much advantage, but more recently immunologic manipulation with drugs such as ipilimumab have shown promise. Thus far, the mutation status does not appear to affect survival outcomes, but NRAS mutations are relatively frequent and could be targeted in this disease by MEK inhibitors in the future.