Massive pleural effusion secondary to pancreaticopleural fistula: a case report

Introduction: Pancreaticopleural fistulas (PPF) are uncommon etiologies of pleural effusion. Though infrequent, PPFs can cause severe hydrothoraces. We report a case of massive pleural effusion with multi-system complications from a PPF. Description: A 13-year healthy female with 1 week of intermittent cough, shortness of breath and fever was admitted to the PICU with tachycardia, difficulty breathing and chest pain. Physical exam notable for absent breath sounds on left. Initial evaluation unremarkable including CRP and procalcitonin, x-ray with left chest opacification. CT revealed a large left pleural effusion with mediastinal shift, multiple left sided venous thrombi, small right lung pulmonary thromboembolism, and right common iliac vein thrombus. Thoracentesis produced 3L of serosanguinous fluid. Hematologic, oncologic, rheumatologic and infectious evaluations were initiated and unrevealing. The pleural effusion reaccumulated within 48 hours. A chest tube was placed with 2.5L of fluid drained. Abdominal CT revealed areas of renal infarct, dilatation of the pancreatic duct and a focal area of nonenhancement. Serum amylase and lipase were elevated (256 U/L and 575 U/L). MRCP 3 days later demonstrated interval enlargement of a large cystic structure traversing from the lower aspect of the mediastinum, extending retroperitoneally and replacing the majority of the pancreatic gland, concerning for abscess or pseudocyst. Pleural fluid pancreatic enzymes were elevated (amylase >1700 U/L, lipase >2400 U/L). ERCP demonstrated pancreas divisum with pancreatic ductal dilation and a PPF. Following ductal stent placement, pleural effusion resolved and chest tube was removed. Patient was treated with enoxaparin for venous thrombi and discharged home in stable condition. Discussion: This case highlights the need for inclusion of PPF into the differential of a large, insidious pleural effusion. Notably the patient had no abdominal pain, nausea, or tenderness to palpation which delayed diagnosis. Etiology was a pancreas divisum, a congenital anomaly with pseudocyst development. Thromboembolic disease presumed secondary to vascular inflammatory changes secondary to adjacent effusion. Endoscopic intervention was effective with quick resolution. Consideration of PPF is essential in early diagnostic evaluation.