SESSION TITLE: Medical Student/Resident Pulmonary Manifestations of Systemic Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Hepatic hydrothorax is a well-recognized pulmonary complication of decompensated liver cirrhosis that can be found in 5-11% of cases. It typically presents as exertional dyspnea in patients with Child-Pugh Class (CPC) B or C cirrhosis and abdominal ascites. The pleural effusion involves the right lung approximately 80% of the time, and pleural fluid analysis is consistent with a transudative effusion. Underlying infection or malignancy should be ruled out. Transudative chylothorax is an exceedingly rare manifestation of portal hypertension in this patient population. CASE PRESENTATION: A 46-year-old man with CPC B, MELD 19 alcoholic liver cirrhosis who recently underwent a transjugular intrahepatic portosystemic shunt (TIPS) procedure with revisions for refractory ascites, presented with progressive cough and dyspnea on exertion for 2 weeks. He reported needing a therapeutic paracentesis approximately every 10 days prior to TIPS; however, since his most recent TIPS revision 4 weeks prior to presentation, he did not have recurrence of his ascites. Exam was notable for diminished breath sounds throughout the right lung fields and trace ascites. Chest radiograph revealed a moderate pleural effusion at the right lower lobe. A thoracentesis yielded 1.5 liters of milky yellow fluid with initial labs suggesting a transudative effusion. A chest tube was placed. Given the milky appearance, further studies were sent, revealing triglycerides at 335 mg/dL and cholesterol at 11 mg/dL, consistent with chylothorax. To evaluate for other etiologies of chylothorax, lymphoscintigraphy was performed, which did not reveal any lymphatic leak or thoracic duct injury. A CT scan of the chest did not demonstrate any lesions concerning for infection or malignancy, and pleural fluid cultures and cytology confirmed the absence of either. The patient underwent TIPS revision with angioplasty, with improvement of the transhepatic pressure gradient. The patient was discharged after increasing his home dose of diuretics and remained asymptomatic at his follow-up appointment 1 week later. DISCUSSION: Liver cirrhosis is an underappreciated cause of chylothorax, with only about 20 cases described in the literature. The pathophysiologic mechanism is thought to be mediated by elevated venous pressures caused by portal hypertension. Diagnostic thoracentesis is required in these patients to rule out malignancy or infection, which are also known etiologies of chylothorax. When the effusion is transudative, interventions aimed at decreasing portal hypertension, such as TIPS, should be considered to prevent recurrence of the chylothorax. CONCLUSIONS: Chylothorax is a rare complication of liver cirrhosis that can be successfully treated by medically managing ascites and/or by TIPS. Reference #1: Chaaban T, Kanj N, Aki IB. Hepatic hydrothorax: an updated review on a challenging disease. Lung. 2019; 197:399-405. Reference #2: Mukherjee A, Sehgal IS, Mittal BR, Dhooria S. Transudative chylothorax: an uncommon illness due to a common cause. BMJ Case Rep. 2018; Feb 7. pii: bcr-2017-223158. Reference #3: Tsauo J, Hoon Shin J, Han K, Yoon HK, Ko GY, Ko HK, Gwon DI. Transjugular intrahepatic portosystemic shunt for the treatment of chylothorax and chylous ascites in cirrhosis: a case report and systematic review of the literature. J Vasc Interv Radiol. 2016; 27: 112-116. DISCLOSURES: No relevant relationships by Argin Baghramian, source=Web Response No relevant relationships by Stefano Iantorno, source=Web Response No relevant relationships by Sonia Lin, source=Web Response No relevant relationships by Alex Rosenberg, source=Web Response