Recurrence of malignant melanoma presenting as black-colored pyopneumothorax: a rare entity

We report a 63-year-old patient with black-colored pus (pyopneumothorax) resulting from an infected pleural effusion associated with metastatic malignant melanoma of the skin. The patient was also positive for Pseudomonas, so the color was unexpected. Although rare, malignant melanoma can present as a black pleural effusion due to the presence of melanocytes in the pleural fluid. Black pleural fluid should raise the suspicion of malignant melanoma.