Bronchus sign on HRCT thorax: presenting sign of Wegener granulomatosis with lung involvement — misdiagnosed as TB in presence of acino-nodular pattern on imaging

Abstract Tuberculosis is the most common diagnosis in India in presence of constitutional symptoms such as cough, fever, and weight loss with lung parenchymal abnormality irrespective of microscopy or nucleic acid amplification test abnormalities in high TB prevalent tropical settings. Pulmonary manifestations of systemic vasculitis have very diverse involvement ranging from the nodule to consolidation. Bronchus sign is classically described in lung malignancies than Wegener disease. The acino-nodular pattern is classical of pulmonary tuberculosis, sometimes documented in fungal infections. In this case report, a 45-year-old female, presented with constitutional symptoms with lung parenchymal nodules, without mycobacterial microscopic or genome documentation, received empirical antituberculosis treatment with the progression of the disease without clinical or radiological response. Bronchoscopy workup is inconclusive and tropical screen for bacterial, fungal, TB, and malignancy was negative. Vasculitis workup was done in view of the presence of persistent fever and documented PR3-ANCA positive with very highly raised titers. We have started on steroid and cyclophosphamide and clinical response documented with near-complete resolution of shadows in 12 weeks. Pulmonary manifestations of Wegener disease are rare and underestimated and early pickup of the entity in course of illness will have a good outcome with an excellent prognosis.