A47-28 Amylase-Positive Pleural Effusion Secondary to Jejunal Perforation: A Rare Case Report

Abstract Introduction Pleural effusions are a frequent clinical finding, with etiologies ranging from benign transudates to inflammatory or malignant processes. Light’s criteria are used to differentiate between transudative and exudative effusion, which can help guide therapy. An amylase-positive pleural effusion can be suggestive of causes such as esophageal perforation or pancreatitis. We present a rare case of amylase-positive pleural effusion secondary to jejunal perforation. Case Presentation An 84-year-old woman with a history of heart failure, coronary artery disease, hypertension, and osteoarthritis was admitted after an elective right total hip arthroplasty. Her postoperative course was complicated by anemia requiring transfusions. On postoperative day 4, she developed acute abdominal pain, nausea, and dyspnea. Physical examination showed abdominal tenderness with guarding. Laboratory tests revealed white blood cell count 20.5 k/cumm, hemoglobin 10.3 g/dL, and creatinine 2.67 mg/dL. Chest X-ray showed a right pleural effusion with atelectasis, and abdominal X-ray showed significant stool burden. Computed tomography of the abdomen and pelvis revealed hemoperitoneum, small bowel thickening, and mesenteric edema, suggesting jejunal perforation. She underwent emergent exploratory laparotomy for surgical repair and was started on broad-spectrum antibiotics. Thoracentesis yielded 1000 mL of bloody exudative fluid with fluid protein 3.7 g/dL, lactate dehydrogenase (LDH) 952 U/L. Repeat chest X-ray three days later redemonstrated right pleural effusion and thoracentesis drained 375 mL of exudative bloody fluid with amylase 224 U/L, protein 2.9 g/dL, and markedly elevated LDH 5053 U/L. Pleural fluid cultures grew Candida glabrata. She later developed septic shock and respiratory failure, requiring intubation and vasopressor support. Despite aggressive management, her clinical condition deteriorated and was later transitioned to comfort measures, and she passed away. Discussion Amylase-positive pleural effusions most commonly arise from pancreatic pathology, esophageal rupture, or malignancy, such as lung or ovarian tumors. Association with small bowel perforation is infrequent and poorly documented. The likely mechanism involves transdiaphragmatic spread of amylase-rich fluid from the perforated small bowel into the pleural space. This case expands the differential diagnosis of amylase-rich pleural effusion to include small bowel perforation, and physicians should consider it as a potential cause of amylase-positive pleural effusion. Early recognition of this rare association can be lifesaving and guide urgent surgical intervention. This abstract is funded by: None