Pulmonary metastasis with endobronchial spread from sinonasal melanoma during a 9-year follow-up

A 60-year-old woman was diagnosed with pulmonary metastasis with endobronchial spread of sinonasal melanoma 9 years after the initial treatment. She had originally been diagnosed with sinonasal malignant melanoma and received chemotherapy combined with carbon ion radiotherapy. During routine follow-up, chest CT showed a nodular lesion on the left upper lung lobe. Bronchoscopic examination showed diffuse melanosis without intrinsic masses from the left main bronchus to the peripheral bronchial mucosa. Transbronchial biopsy was performed for both the pulmonary lesion and endobronchial melanosis lesions. Melanoma cells were histologically detected in both the mucosal and submucosal layers.