Black pleural effusion

Abstract

A 56-year-old man undergoing treatment for a prostatic acinar adenocarcinoma was referred to us in May, 2014, for assessment of a massive right pleural eff usion (fi gure). Although the eff usion was large, he had only mild shortness of breath and was admitted originally for urinary incontinence. A pleural aspiration showed black pleural fl uid (fi gure). This fl uid was determined to be an exudate with very high concentrations of protein (85 g/L; serum protein 56 g/L), lactate dehydrogenase, and amylase. We drained about 3 L of this black pleural fl uid from the patient over the following 24 h. Fibreoptic bronchoscopy was normal. However, a thoracoscopy showed nodularity of the visceral and parietal pleura with signifi cant pleural thickening. Pleural fl uid cytology showed groups of neoplastic cells arranged in balls, gland, and papillioid confi guration in a haemorrhagic background with mesothelial cells and mixed population of infl ammatory cells. Immunohistochemistry studies favoured a diagnosis of an adenocarcinoma of pulmonary origin. Percutaneous and thoracoscopic pleural biopsies also confi rmed this diagnosis. The patient is receiving treatment for lung and prostate cancer and at last follow-up in February, 2015, he had poor performance status and the pleural eff usion was persisting. Black pleural eff usions are extremely rare and have been reported previously in patients with pleural infections caused by Aspergillus niger and Rhizopus oryzae, metastatic melanoma, adenocarcinoma of the lung, pancreaticopleural fi stula, oesophageal perforation during activated charcoal treatment for a drug overdose, and in patients actively using crack cocaine. The black pleural fl uid in our patient was most likely due to haemolysis and the presence of haemosiderinladen macrophages after a massive bleed into the pleura. The absence of clinically signifi cant symptoms in spite of the massive eff usion and the fact that the fl uid was black and not red suggest that the fl uid collected over a prolonged period of time and that the bleeding would have occurred a long time before presentation. Increased concentrations of amylase in the pleural fl uid, as noted in our patient, are commonly seen in patients with lung cancer—most frequently in those with adenocarcinomas.