Nasal Malignant Melanoma With an Inverted Papilloma in the Contralateral Nasal Cavity: A Case Report.

Background: We describe a patient with sinonasal mucosal melanoma (SNMM) and an inverted papilloma, which existed independently in both nasal cavities. Case presentation: We describe an unusual case of a 74-year-old male patient with SNMM and an inverted papilloma. He presented with symptoms of coughing up blood and pain in the left forehead. The patient underwent surgical resection of the lesion, and the SNMM and inverted papilloma were confirmed by histopathology. The patient refused further treatment after surgery, but was re-admitted 7 months later with local recurrence of the left tumor and systemic metastases. Conclusions: Nasal malignant melanoma with an inverted papilloma in the contralateral nasal cavity is rare and can easily be misdiagnosed as the same tumor by imaging. Simultaneous histopathology of bilateral nasal masses is very necessary. The recommended treatment is surgery for the inverted papilloma. An SNMM is a devastating tumor with poor outcomes.