Delayed Chylothorax After Endometrial Carcinoma: A Case of Confirmed Thoracic Duct Leak Successfully Managed Conservatively.

Chylothorax is an uncommon cause of pleural effusion resulting from the disruption or obstruction of the thoracic duct or its tributaries. Malignancy is a major non-traumatic cause, most commonly lymphoma, while involvement of gynecologic malignancies is exceedingly uncommon and largely limited to isolated case reports. We report the case of a 61-year-old woman with a prior history of poorly differentiated endometrial carcinoma treated in 2022 with total abdominal hysterectomy, bilateral salpingo-oophorectomy, and adjuvant brachytherapy, who presented three years later with progressive dyspnea, cough, anorexia, and weight loss. Imaging revealed recurrent left-sided pleural effusion. Diagnostic thoracentesis yielded milky fluid, and pleural fluid analysis demonstrated markedly elevated triglyceride levels with relatively low cholesterol, consistent with chylothorax, with negative microbiology and cytology for malignant cells. Intranodal lymphangiography confirmed an active thoracic duct leak into the left pleural cavity. Despite this, conservative management was pursued due to the patient's stable clinical status and preference to defer intervention, consisting of therapeutic thoracentesis and dietary modification with a low-fat diet supplemented by medium-chain triglycerides. This resulted in significant clinical and radiological resolution. This case highlights a delayed presentation of chylothorax following endometrial carcinoma and emphasizes a systematic diagnostic approach with individualized management, demonstrating successful conservative resolution despite a confirmed thoracic duct leak.