Chylothorax as an Unusual Initial Manifestation of Diffuse Large B-Cell Lymphoma in an 86-Year-Old Woman: A Reflection of Diagnostic Reasoning and Age in Therapeutic Decisions

Chylothorax is a rare presentation of lymphoproliferative disorders, responsible for only a small proportion of non-traumatic pleural effusions in large series. In older adults, its recognition can be challenging, often delaying diagnosis and treatment. We report an 86-year-old woman admitted with progressive dyspnea and a large right pleural effusion. Thoracentesis yielded a milky fluid with high triglycerides, confirming chylothorax. Cytology was negative for malignant cells, and a CT scan revealed an extensive retroperitoneal mass encasing the aorta and inferior vena cava, highly suggestive of lymphoproliferative disease. An inguinal lymph node biopsy established the diagnosis of diffuse large B-cell lymphoma. The patient was managed with a low-fat diet enriched with medium-chain triglycerides, subcutaneous octreotide, and chest drainage, leading to complete resolution of the effusion. Corticosteroid therapy was initiated, resulting in clinical improvement, weight gain and marked recovery of performance status, leading to the discharge of the patient. She was subsequently referred to Haematology and proposed for chemotherapy. Despite advanced age, the patient achieved significant improvement, reinforcing that chronological age alone should not preclude adequate therapy and even in very old patients, targeted treatment can yield meaningful recovery and quality of life.