Right upper lobectomy after immunotherapy for primary malignant melanoma of the lung: a case report and literature review

Malignant melanoma is a malignant tumor of melanocytes. All body organs can be invaded by it; however, the skin is the most common site of invasion. Melanomas involving the lungs are almost always metastatic and it is extremely rare to find a true primary malignant melanoma of the lung (PMML). Compared to cutaneous melanoma, mucosal melanoma has a different biology and clinical appearance. Since there are no standards for the diagnosis and treatment of PMML, it is treated differently. We reported a patient with PMML underwent surgery after programmed cell death 1 (PD-1) immunotherapy. A 62-year-old female patient presented with an occupying lesion in the right upper lung lobe found on physical examination. A computed tomography (CT) scan was done, and the results showed a lobulated soft tissue mass shadow of roughly 54 mm × 50 mm in the upper lobe of the right lung. The histological results of a CT-guided percutaneous lung biopsy were consistent with malignant melanoma. She was identified as having primary melanoma of the lung after undergoing a full physical examination to rule out occult primary tumor metastases. The patient received a total of 33 cycles of immunotherapy (PD-1). We did a right upper lung lobectomy after shrinking the melanoma in the right lung's upper lobe to a size of 16 mm × 10 mm. After the operation, the patient was monitored for 6 months and made a full recovery without recurrence. The preoperative immune system in combination with a surgical procedure may boost patients' chances of survival. These findings need to be confirmed in more clinical research.