Milroy's Disease With Chronic Lymphedema and Recurrent Bilateral Chylothorax

Abstract Milroy's disease is an autosomal dominant congenital disorder affecting the lymphatic system, primarily caused by mutations in the Ferritin light chain 4(FLT4) gene. It disrupts lymphatic vessel development, resulting in lymphatic drainage obstruction. The condition can lead to chronic lymphedema and, rarely, complications like recurrent chylothorax. A 47-year-old woman with a history of Milroy's disease and chylothorax was transferred from outside hospital(OSH) for suspected chylothorax and hematuria/chyluria. At the time of presentation, the patient reported shortness of breath and sensation of fluid building up in her lungs. Chest Xray(CXR) and CTA chest from OSH showed large bilateral pleural effusions (R>L), focal consolidations (R>L), with compressive atelectasis in lower lobes. Patient underwent bilateral thoracentesis with right sidedchest tube placement at OSH. Pleural fluid was reddish and cloudy(Image 1D), and pleural fluid analysis revealed WBC 419, LDH 131, glucose 73, cholesterol 64, and triglyceride 635, suggestive of chylothorax. Cultures showed no pathogenic growth. On admission, vitals were BP 123/79, RR18, O2 sat 100% on room air. Labs showed hemoglobin 7.5, hematocrit 25.2, no leukocytosis, serum albumin 2.5, and normal BNP. Patient was started on a low-fat diet to reduce long chain triglycerides(LCTs) intake and intravenous octreotide. On hospitalization day(HD) 2, CXR(Image1A) showed worsening right pleural effusion with blunting of left costophrenic angle. On HD 8, CXR(Image 1B) showed mild worsening bilateral pleural effusion with increased central interstitial markings. Chest tube output also fluctuated between 100 to 1000 ml during the initial 10 days of hospitalization(Image 1E). Cardiothoracic surgery evaluated the patient for possible pleurodesis due to worsening pleural effusion. Lymphangiography by interventional radiology showed no thoracic duct leak. Post-procedure CXR (Image 1C) showed stable right pleuraleffusion with consolidation and chest tube output remained minimal in the following days (Image1E). The patient showed clinical improvement, so invasive procedures were deferred. The plan is to remove the chest tube once output remains under 100 ml, with close outpatient follow-up in pulmonology. Replacing long-chain triglycerides (LCTs), which play a key role in chyle formation, with medium-chain fatty acids (MCFAs), which are absorbed directly into the bloodstream, reduces the production of chyle. Octreotide further decreases thoracic duct fluid by inhibiting gastric, pancreatic, and biliary secretions, thereby reducing chyle output. This case underscores the importance of conservative management in Milroy's disease to avoid invasive procedures like thoracic duct surgery or embolization, which offers valuable insights for healthcare providers to improve patient care.