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 2 mm Clark IV cutaneous malignant melanoma 15 months earlier, presented with rapidly progressive dyspnea, left pleuritic chest pain, and weight loss. CT Pulmonary Angiography (CTPA) demonstrated bilateral pulmonary emboli and findings suspicious of mesothelioma. There was no evidence of infection or malignancy in the hemorrhagic 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 late