Surgery for Treatment of Primary Sinonasal Mucosal Melanoma in Patients Treated with Systemic Immunotherapy for Distant Disease

Background Sinonasal mucosal melanoma is a rare, aggressive malignancy associated with advanced stage at initial presentation, high rates of disease recurrence, propensity for distant metastasis, and poor overall prognosis. Surgical resection is widely accepted as a critical component for definitive treatment. Systemic immunotherapy, including multiple newer agents, has been used to treat metastatic or unresectable disease, but limited evidence exists on its efficacy in locoregional control when used in conjunction with surgical resection for primary mucosal lesions.

Methods Retrospective review of four patients at an academic university hospital with primary sinonasal mucosal melanoma treated with systemic immunotherapy followed by surgical resection of the primary lesion.

Results A total of four patients were identified. In all cases, patients were treated with a combination of surgical resection of the primary lesion and systemic immunotherapy. Three patients were initially treated with surgery at the primary site followed by immunotherapy for distant metastases. Response to immunotherapy at the sites of primary and metastatic disease was seen in two patients; however, the location of the primary lesion was the first site of disease recurrence in both. All four patients developed disease progression or recurrence at the primary site following initiation of immunotherapy for which they underwent surgical resection. None of the patients developed intraoperative or postoperative cerebrospinal fluid leak. Two patients remain in follow-up actively receiving treatment at 33 and 5 months after initial treatment; two succumbed to the disease at 135 and 16 months after initial treatment.

Conclusion Surgical resection plays a critically important role in the treatment of sinonasal mucosal melanoma regardless of the presence of metastases and whether immunotherapy will be given. This case series suggests that, though immunotherapy may demonstrate some efficacy in managing distant disease, surgery may be the most effective means of treatment for the primary site.