Case Presentation:
A 58-year-old man with a medical history of recurrent acute on chronic pancreatitis due to alcohol use disorder presented with a 3-day history of right-sided pleuritic chest pain and dyspnea. Chest X-ray revealed a new large right-sided pleural effusion. Analysis of the aspirated serosanguinous exudative pleural fluid yielded a total amylase of 24,600 U/L, pancreatic amylase isoenzyme of >17,600 U/L, and a lipase of >110,000 U/L (serum lipase was 347 U/L). Cytology analysis for malignancy was negative.
Esophagogastroduodenoscopy (EGD) was normal except for atrophic appearance of the esophageal mucosa. Computed tomography (CT) scan of the chest, abdomen, and pelvis with IV contrast revealed a pancreatic fistula extending from the area of the pancreatic tail to the posterior mediastinum where it approached the right pleural space, representing a pancreaticopleural fistula. Endoscopic retrograde cholangiopancreatography (ERCP) revealed a near normal pancreatic duct with no obvious active extravasation of contrast. A temporary stent was placed in the pancreatic duct extending to the tail. The patient was discharged to home in a stable condition without re-accumulation of pleural effusion.
Follow-up CT scan six weeks later demonstrated a complex fistulous connection that originated from the pancreatic tail and tracked superior-posteriorly towards the esophagus and ultimately into the right and left pleural space. A repeat ERCP revealed contrast extravasation due leak from the pancreatic duct in the tail of the pancreas. The previous stent was removed and replaced with a new stent into the ventral pancreatic duct.
Discussion:
Pancreaticopleural fistula is a rare complication of chronic pancreatitis, although it can be seen in acute pancreatitis as well. It occurs most often in middle-aged men with a history of chronic alcohol abuse. No specific diagnostic criteria have been developed. The diagnosis should be suspected when a large pleural effusion has a very high level of amylase, especially when greater than 50,000. Imaging evaluation to detect the fistula includes CT scan, ERCP and magnetic resonance cholangiopancreatography (MRCP), with a sensitivity of 48%, 78% and 80%, respectively.
Conclusions:
ERCP is the preferred imaging modality in pancreatic fistulas because it provides direct visualization of the duct and allows access for endoscopic treatment, such as stent placement. However, as was seen in this case, even an extensive fistula can be missed on ERCP and its sensitivity in detecting pancreatic fistulas is highly user dependent. Pancreaticopleural fistula is a rare entity that requires a high level of suspicion for diagnosis and treatment should be considered in likely cases even if diagnostic imaging is negative.