Pulmonary tuberculosis masquerading as metastatic lung disease

Abstract

A 30-year-old, HIV-negative female, who had never smoked, was referred for evaluation of lung metastasis. She had abdominal pain, occasional fever and weight loss for 3 months. Progressive breathlessness was present for 15 days. Her physical examination was unremarkable. Chest radiography (figure 1) showed bilateral nodular opacities with indistinct margins in all the lung zones. Computed tomography (CT) of the thorax demonstrated multiple round nodules of variable sizes scattered throughout both lung fields, suggestive of metastatic lung disease. Abdominal ultrasonography revealed multiple large retroperitoneal lymph nodes, which were confirmed on CT. Several sputum samples for acid-fast bacilli (AFB) and malignant cytology were negative. Her bronchial aspirate was positive for AFB and GeneXpert (Cepheid, Sunnyvale, CA, USA) detected Mycobacterium tuberculosis without rifampicin resistance. Transbronchial biopsy revealed caseating granulomas consistent with pulmonary tuberculosis. She was then referred to DOTS (directly observed therapy, short course) centre for initiation of antituberculous therapy. Subsequently, the bronchial aspirate also cultured M. tuberculosis . Pulmonary TB should be considered in the differential diagnosis of bilateral pulmonary nodules simulating metastasis <http://ow.ly/TLQl4>