Idiopathic Chylothorax: Is It a Benign or Malignant Diagnosis?
Naffouj S, and Omar J. Idiopathic Chylothorax: Is It a Benign or Malignant Diagnosis? J Gen Intern Med 2019; 34(2):S555-S556.
J Gen Intern Med
Learning Objective #1: Diagnose idiopathic chylothorax Learning Objective #2: Manage chylothorax CASE: A 29-year-old healthy male presented with acute onset of dyspnea and right-sided pleuritic chest pain. CT scan of the chest showed large right-sided pleural effusion. Thoracentesis was performed, draining 2 liters of turbid white pleural fluid and a chest tube was placed. Fluid analysis revealed exudative effusion with lymphocytic predominance and triglyceride (TG) of 1,100 mg/dl consistent with chylothorax. Pleural fluid cytology and cultures were negative for malignancy and infection. Patient was made nil per os, total parenteral nutrition (TPN) and IV octreotide were started. High-volume chyle leakage was persistent. Patient underwent lymphangiogram, which showed chyle leak from the thoracic duct (TD) at the level of T7-T8. He underwent embolization, however, output did not improve. Patient underwent video-assisted thoracoscopy (VATs) and TD ligation by thoracic surgery. Pleural biopsy was negative for malignancy. Serum LDH, alpha-fetoprotein, beta-human chorionic gonadotropin, HIV, acid-fast bacilli, fungal, and anaerobic cultures were all negative. Peripheral blood smear was negative for dysplasia and blasts. Full body CT did not show any evidence of malignancy. Output trended down, and chest tube was removed when chest X-ray showed resolution of pleural effusion. Diet was advanced to low-fat, medium chain triglyceride (MCT) diet. There was no leak recurrence at 1-month follow-up. IMPACT/DISCUSSION: Chylothorax is the presence of chyle in the pleural space with a TG level > 110 mg/dl or evidence of chylomi-crons in the pleural fluid. Non-traumatic chylothorax is a rare condition and can be due to many disease processes. A thorough evaluation of the most common causes of non-traumatic chylothorax includes malignancy (lymphomas, lung and mediastinal cancers), infections (tuberculosis, fungal infections), and congenital disorders of the lymphatic system, which were negative in our case. Conservative management includes either nothing by mouth or a low-fat diet with MCTs, which are absorbed directly into the portal system, bypassing the TD to reduce chyle flow and promote healing. TPN is used to replace proteins, electrolytes, and deliver lipids directly into the bloodstream, thereby bypassing the lymphatic system and decreasing chyle flow. Octreotide is an adjunct to help reduce chyle absorption from the intestines. When conservative measures fail, there are many interventional modalities to consider, including TD embolization, TD ligation, or pleurodesis. For our patient, a combination of conservative and operative interventions was performed given high-output of chyle and absence of a clear etiology, resulting in leakage resolution. Conclusion: It is crucial to perform a comprehensive assessment in non-traumatic chylothorax to exclude occult underlying etiology. Initial conservative management includes dietary modifications. If there is no improvement, interventions are available to repair TD and reduce chyle output.