Concurrence of primary pulmonary malignant melanoma with invasive pulmonary adenocarcinoma: a case report

BACKGROUND: Primary pulmonary malignant melanoma (PPMM) is an extreme rarity in clinic practice, accounting for only 0.01% of all primary pulmonary tumors. And its diagnosis should meet clinical and pathological diagnosis criteria in addition to excluding the possibility of metastatic melanoma. The mainstay of treatment is surgery. The concurrence of primary pulmonary malignant melanoma and invasive pulmonary adenocarcinoma has not been reported before. CASE PRESENTATION: Herein we report the case of a 39-year-old woman who was asymptomatic and accidently found to have the concurrence of PPMM with invasive pulmonary adenocarcinoma. Before considering the diagnosis of primary pulmonary malignant melanoma, a systemic positron emission tomography-computed tomography (PET-CT) was done to excluding primary tumor metastasis from other sites. The pathological biopsy proved that two lesions in the right middle lobe were invasive pulmonary adenocarcinomas and the mass in the right lower lobe was malignant melanoma. She underwent right middle and lower lobectomy of the lung with mediastinal and hilar lymph dissection. She refused adjuvant chemotherapy, genetic molecular testing or immunotherapy. Fifteen months later she had brain metastasis. Then she received brain radiotherapy and underwent follow-up at the outpatient clinic regularly. CONCLUSIONS: We experienced a case of concurrent PPMM and invasive pulmonary adenocarcinoma. The patient reported here is the first case of primary pulmonary malignant melanoma combined with invasive pulmonary adenocarcinoma. This patient remained disease-free 15 months after lung surgery.