Pulmonary tuberculosis in patients with idiopathic pulmonary fibrosis

Patients with idiopathic pulmonary fibrosis (IPF) have an increased risk of pulmonary tuberculosis. However, detecting pulmonary tuberculosis may be difficult due to the underlying fibrosis. The aim of this report is to describe the radiological and clinical findings of pulmonary tuberculosis in patients with idiopathic pulmonary fibrosis.

We reviewed 143 consecutive patients in whom IPF was diagnosed by either the histological or radio-clinical criteria. Among them, nine patients were histologically (n=2) or bacteriologically (n=7) confirmed to have active pulmonary tuberculosis. The location and patterns of pulmonary tuberculosis were examined on a thin section CT scan.

The most common thin section CT findings were subpleural nodules (n=6; mean diameter, 3.2 cm) and a lobar or segmental consolidation (n=3). The lesions were located most commonly in the right lower lobe (n=4). The incidence of tuberculosis in patients with idiopathic pulmonary fibrosis was more than five times higher than that of the general population.

The atypical manifestation of pulmonary tuberculosis is common in patients with idiopathic pulmonary fibrosis, which may mimic lung cancer or bacterial pneumonia.