Black pleural effusion: etiology, diagnosis, and treatment

Black pleural effusion (BPE) is an extremely rare entity. This review aims to increase the attention of thoracic physicians and surgeons to the differential diagnosis and management of unfamiliar cases with BPE.

Searching MEDLINE, Pubmed, and Web of Science databases with the words of "black pleural effusion" in title/abstract yielded 86 articles relevant to the topic of the review. There were only 20 case reports describing BPE with different underlying causes.

BPE may occur as a result of fungal Aspergillus niger or Rhizopus oryzae infection, metastatic melanoma, pancreaticopleural fistula (PPF), hemolysis after massive intrapleural bleeding, or other miscellaneous causes. A stepwise approach should be followed for diagnosis of BPE including chest x-ray, diagnostic thoracocentesis, cytology and culture of the pleural fluid, thoracic or thoraco-abdominal computed tomography (CT), and tissue biopsy for pathological examination. Pleural fluid drainage is a sufficient treatment of BPE in most of the cases, and pleurodesis can be performed as part of palliative care. The definite treatment of the underlying causes of BPE, namely, pulmonary aspergillosis, metastatic melanoma, pulmonary adenocarcinoma, or PPF, is mandatory to achieve favorable outcome.

BPE is not a common clinical condition which may hide a critical disease including invasive pulmonary aspergillosis, metastatic melanoma, lung cancer, and PPF, thus awareness of this rare entity is crucial to prevent subsequent complications and to avoid delayed diagnosis of the underlying cause.