Background : Black pleural effusion is an exceedingly rare and unfamiliar presentation, often indicating an underlying critical medical condition.

Methods : This case report describes a unique presentation of right-sided black pleural effusion in a 30-year-old male with a history of chronic alcoholism and prior acute pancreatitis. The patient presented with chest pain and exertional breathlessness, which led to the discovery of a massive pleural effusion. Clinical examination revealed notable findings, including right-sided dullness on percussion and reduced vocal fremitus. Pleural fluid analysis exhibited distinctive characteristics, such as a brownish, hazy appearance, elevated protein content, and notably, high fluid amylase and lipase levels. Contrast-enhanced computed tomography(CECT) revealed acute on chronic pancreatitis, while endoscopic retrograde cholangiopancreatography (ERCP) confirmed a ductal blowout at the neck of the pancreatic duct.

Results : Intervention involved distal pancreatic duct cannulation, pancreatic sphincterotomy, and the placement of a pancreatic duct stent. The patient demonstrated significant improvement with a marked reduction in pleural effusion following this procedure.

Conclusions : A black pleural effusion resulting from acute pancreatitis with a background of pancreatic ascites and pancreatic-pleural effusion is an extremely rare finding. Acute pancreatitis should be part of the differential diagnosis of the black pleural effusion, especially when the pleural fluid analysis shows elevated amylase and lipase levels. Black pleural effusion is a rare and unfamiliar type of pleural effusion that may indicate an underlying critical disease. Hence, a comprehensive evaluation is essential to diagnose the underlying etiology and initiate appropriate management in order to avoid fatal complications.