Sinonasal mucosal melanoma: A 9-year experience from a tertiary-cancer centre in South India

Sinonasal tract malignancies are uncommon, representing not more than 5% of all head and neck neoplasm. Primary sinonasal mucosal melanomas (SNMM) are rare and constitute 1% of all melanomas and about 4% of all sinonasal tumors. Mucosal melanomas are biologically distinct from cutaneous melanomas. Etiology of mucosal melanomas is still under speculation. We retrieved nine cases of SNMM from our archives over a period of 9 years from 2010 to 2018. The aim was to identify the clinical characteristics, histopathological features, disease progression, and treatment of this disease. The most common symptom was epistaxis. The mean duration of symptoms was 3 months. Nasal cavity along with maxillary sinus was the most common site. The male to female ratio was 4:5 and the mean age was 63 years. The tumors showed varying histomorphology including epithelioid, spindle cell, and undifferentiated types. Immunohistochemical studies confirmed the diagnosis with positive reactions for S100 and melanocytic markers HMB45, Melan A. Surgery was the first line of management with postoperative radiotherapy (RT) for margin positive cases. Three inoperable cases were given palliative RT. Four cases developed recurrence. Recurrences were managed with RT in most cases. Three patients died due to disease. The 1 year recurrence-free survival (RFS) rate was 44% and 2 years' RFS rate was 22%. The 5-year overall survival rate was 28%. More studies are required to understand the utility of chemotherapy and immunotherapy in treatment of this rare entity. Multi-institutional studies are needed for better understanding this rare malignancy.