[Successful treatment of refractory chylothorax associated with diffuse large B-cell lymphoma by multidisciplinary care].

Chylothorax is an intrathoracic leakage of chyle due to thoracic duct damage. Malignant lymphoma is the most common nontraumatic cause of chylothorax. In March 2019, a 74-year-old woman presented to our department with bilateral pleural effusion and mesenteric/retroperitoneal masses. She was diagnosed with diffuse large B-cell lymphoma upon performing a biopsy. In May 2019, she was hospitalized for dyspnea due to pleural effusion, and thoracentesis revealed abundant chyle. Although the tumor shrunk after chemotherapy, chylothorax improvement was poor; thus, she could not be discharged. For the management of refractory chylothorax, lymphangiography, thoracic duct embolization, and pleurodesis were performed, and the chylothorax improved immediately. However, in May 2020, right chylothorax recurred without a relapse of malignant lymphoma, which did not improve with conservative treatment. Lymphangiography was performed again; however, treatment via the lymphatic vessels was difficult. Thus, pleurodesis was performed four times, after which the chylothorax regressed. Chylothorax is often refractory. When chemotherapy for malignant lymphoma does not improve chylothorax, multidisciplinary treatment is effective.