A 52-year-old female with a history of anti-tuberculosis therapy for six months was referred to our department because a new mass appeared on chest CT during a regular routine checkup. Six months ago, the patient complained of right chest pain for one year. At that time, the CT showed a 1.7x1.4cm nodule in the right-superior pulmonary lobe (Figure 1A and B). There were no apparent lesions in the right-inferior lobe (Figure 2A and B). She denied history of smoking, malignancy, diabetes and other serious illness. Since both interferon-gamma release assays (IGRAs) and tuberculin skin tests were positive, a diagnosis of pulmonary tuberculosis was made. The patient started an induction chemotherapy consisting of isoniazid, rifampicin, ethambutol, pyrazinamide and levofloxacin. Due to the liver damage, the regimens were changed to isoniazid, rifapentine and ethambutol. Her symptoms were gradually improved. A week before this admission, CT scans revealed a new occupying lesion (3.4cm x 2.3cm) in the right-inferior lobe (Figure 2C and D), whereas the original nodule located in the superior lobe demonstrated improvement (Figure 1C and D). The patient denied symptoms of fever, cough, chest pain or weight loss. White blood cell (WBC) counts were 4.28x109/L with 17.80% lymphocytes. Tuberculin skin test remained positive. Other laboratory results including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), tumor markers, galactomannan test (GM-test), (1, 3)-beta-D glucan test (G-test), autoantibodies related to connective tissue disease were within the normal ranges. HIV test was negative. CT-guided percutaneous lung biopsy demonstrated caseating granulomas (Figure 3). The patient was diagnosed as paradoxical reaction and was continued on anti-tuberculosis therapy. The size of new pulmonary mass was reduced to 1.5cm x 1.3cm one month later (Figure 2E and F) and was further reduced to 0.9cm x 1.1cm (Figure 2G and H) three months later. Currently, the patient is asymptomatic, and the original therapy continues.
Case 1. CT-guided percutaneous lung biopsy shows caseous necrosis and granulomatosis surrounded by epithelioid and multinucleated giant cells. Hematoxylin and eosin, x400.