Pulmonary tuberculosis occurring during the diagnosis and treatment of sarcoidosis complicated by chylothorax: A case report.

Sarcoidosis is a systemic granulomatous disorder, and chylothorax is a rare but severe pleural complication of this disease and exhibits a prominent diagnostic overlap with tuberculosis. The present study reported the case of a 48-year-old woman who was admitted in May 2018 with chronic cough and chest tightness. After hospitalization for 17 days, comprehensive examinations excluded tuberculosis and malignancy, and the patient was finally diagnosed with sarcoidosis complicated with pleural effusion. Treatment with prednisone combined with therapeutic thoracentesis was initiated to relieve symptoms. Chylothorax developed on hospital day 22, and a low-fat diet was added to the treatment regimen; however, 20 days after therapy initiation, the persistent chylothorax showed no notable improvement. Following multidisciplinary consultation, methotrexate was added as adjuvant therapy to control sarcoidosis activity. The patient's symptoms then improved, and the patient was discharged on hospital day 49 with oral medications. Clinical remission was achieved at the 3-month follow-up; however, new tuberculous lesions were identified in the left lung at the 6-month follow-up. Methotrexate was discontinued immediately, prednisone was gradually tapered to a maintenance dose, and standardized anti-tuberculosis therapy was initiated. At the 12-month follow-up, pulmonary tuberculosis had achieved clinical cure following a 6-month course of treatment. Anti-tuberculosis therapy was continued for an additional 3 months as consolidation treatment before discontinuation, whereas maintenance-dose prednisone was continued to control the underlying sarcoidosis. No evidence of sarcoidosis or tuberculosis recurrence was identified at the 25- or 39-month follow-up. Prednisone was gradually tapered and ultimately withdrawn, and the patient achieved a favorable long-term outcome. The present case report describes a patient with sarcoidosis-associated chylothorax who developed new-onset pulmonary tuberculosis during immunosuppressive treatment, highlighting the challenges associated with the differential diagnosis and clinical management of complicated sarcoidosis. Although combination therapy with prednisone and methotrexate was temporally associated with improvement of the chylothorax, clinicians should remain aware regarding the risk of opportunistic infections.