Black pleural effusion: an unusual presentation of metastatic melanoma diagnosed by medical thoracoscopy

Melanoma presenting with black pleural effusion is rare, with only five cases reported till date. In distinction to others, this is the only case where patient did not have a prior diagnosis of melanoma and was diagnosed by thoracoscopy. Reported is the case of a 49-year-old male who presented with dyspnoea and weight loss. Patient had a large left-sided pleural effusion. Ultrasound showed thickened irregular pleura and multiloculated pleural effusion. Diagnostic pleural aspiration was performed, and fluid was black in colour and was exudative lymphocytic. Atypical cells were noted on pleural fluid cytology. Medical thoracoscopy was carried out and histopathology suggested metastatic melanoma. Patient had multiple nevi all over the body, but clinically none was indicative of melanoma. He refused skin biopsy. The case was referred to medical oncology where palliative management was planned. Patient died within two weeks of diagnosis.