Sinonasal Mucosal Melanoma: A 10-Year Experience Of 36 Cases In China

Background: Sinonasal mucosal melanoma (SNMM) is a rare tumor with a poor prognosis. This study aimed to assess the clinical and imaging features, progression, treatment, and possible prognostic factors of SNMM.Methods: Thirty-six patients with SNMM were retrospectively reviewed in the Department of Otolaryngology & Head and Neck Surgery of Xinhua Hospital from January 2008 to December 2017.Results: The age of the first diagnosis was 67.4 +/- 10.8 years; the most common clinical symptoms included epistaxis, nasal obstruction, headache, and facial pain. Most tumors originated in the nasal cavity (63.9%) and at stage IV (77.8%). Melanin in melanoma showed typical signal intensity on magnetic resonance imaging (MRI), T1WI had high signal while T2WI had low signal. 41.6% of patients had the typical MRI findings. Treatment included surgery, surgery with radiotherapy, and radiotherapy only. The follow-up time ranged from 4 to 96 months, with a median time of 22 months, 1-, 3-, and 5-year OS is 80.6%, 36.1%, and 13.9%, respectively. The 3-year OS was better in cases in the T3 stage than the T4 stage (P=0.02). However, tumors that originated from the paranasal sinus had a poorer prognosis than the nasal cavity (P=0.04). The cases receiving postoperative radiotherapy showed poorer prognosis (P=0.02). Other factors were not found to be associated with prognosis, including gender, age, lymph node metastasis, distant metastasis, computed tomography (CT) enhancement, and typical MRI findings.Conclusions: The SNMM was a devastating tumor with poor outcomes; most cases were diagnosed at late stages, which may account for poor prognosis. Tumors with melanin feature MRI findings do not have a better prognosis. The treatment of postoperative radiotherapy is still controversial.