Pancreatitis as a Pulmonary Pathology: A Rare Case of a Pancreaticopleural Fistula Presenting as Recurrent Pleural Effusions Causing Mediastinal Shift

Pancreaticopleural fistula (PPF) is a rare complication of chronic pancreatitis and pancreatic pseudocyst. It can present as recurrent pleural effusions and can be difficult to diagnose and treat. We present the case of a 37-year-old male with a history of chronic idiopathic pancreatitis complicated by a pseudocyst who came in with progressive dyspnea, cough, and pleuritic chest pain. The chest X-ray on presentation showed nearcomplete opacification of the left hemithorax, suggesting a large pleural effusion. Upon thoracentesis, blackbloody fluid was drained, and the pleural fluid analysis was consistent with an exudate with significantly elevated levels of amylase, lipase, and bilirubin. Cytology revealed abundant lipofuscin-laden macrophages, suggesting an intra-abdominal source of the accumulated fluid. A post-drainage CT of the chest showed the resolution of the pleural effusion and an interval decrease in the pancreatic pseudocyst size, indicating a fistulous connection to the pleural space. An endoscopic ultrasound (EUS) was performed with efforts to perform cystogastrostomy aspiration that was hindered by the interference of splenic vasculature obstructing the needle's path. The patient was transferred to another facility for definitive treatment with surgical pancreatectomy and auto islet cell transplant. This case underscores the importance of considering PPF as a possible diagnosis, especially in cases of recurrent pleural effusions and a history of pancreatitis and pancreatic pseudocyst. It also emphasizes the significance of EUS as the preferred modality for pseudocyst evaluation and its potential for minimally invasive treatment.