An unusual case of metastatic malignant melanoma presenting as pseudomesothelioma with intense diffuse pleural FDG uptake demonstrated on FDG PET/CT

A 75-year-old male, non-smoker with history of asbestos exposure, and excision of 2mm Clark IV cutaneous malignant melanoma 15 months prior to the presentation, presented with rapidly progressive dyspnoea, left pleuritic chest pain, and weight loss. CTPA demonstrated bilateral pulmonary emboli and findings suspicious of mesothelioma. No evidence of infection or malignancy in the haemorrhagic pleural fluid aspirate. FDG PET-CT revealed extensive intense FDG uptake throughout the pleura of left hemi-thorax, bilateral hilar and mediastinal lymph nodes, bilateral adrenals and left gluteal musculature. Subsequent pleural biopsy was consistent with metastatic melanoma. The patient was referred for palliative therapy but died 10 days later.