Mediastinal mass in an infant: A rare presentation of extrapulmonary tuberculosis.

Tuberculosis as cause of mediastinal mass, is rare in children, and may be seen in immunodeficiencies. Data on the prevalence of mediastinal tuberculosis and on its clinical spectrum and outcome is lacking in children. A 4.5-month-old boy presented with fever and cough since 7 days and increased respiratory activity. He had respiratory distress with hypoxia. Examination revealed decreased breath sounds on the right lung with tracheal shift to the left. Chest radiograph showed homogenous opacity in the right upper zone, with heterogenous opacity in the right middle and lower zones and tracheal shift to left. Computed tomography scan confirmed the presence of mediastinal abscess. Human immunodeficiency virus status of patient's mother and primary immunodeficiency workup of the child were negative. In view of clinical deterioration and non-responsiveness to 10 days of intravenous antibiotics, tuberculosis workup was done. GeneXpert of the abscess aspirate showed Mycobacterium tuberculosis (rifampicin resistant). Patient was labeled as pre-XDR tuberculosis based on the line probe assay. Antitubercular regimen was modified accordingly (linezolid, amikacin, cycloserine, clofazimine, and ethionamide). The child required invasive mechanical ventilation in pediatric intensive care unit (PICU) for 15 days. The patient showed clinical and radiological improvement and was discharged after 6 weeks of inpatient stay. However, the patient was readmitted 16 days later with linezolid-induced lactic acidosis, developed measles, and succumbed to measles complication (pneumonia).