Objective: To evaluate potential predictors of high resolution CT (HRCT) findings of pulmonary mass caused by tuberculosis (Tbc).
Material and Method: A retrospective study of chest HRCT was performed in 10 patients diagnosed as pulmonary Tbc. The size, characteristics of lesions, enhancement and mediastinal lymphadenopathy were interpreted. The final diagnosis was reached by laboratory and pathological specimens or clinical improvement from treatment of the Tbc.
Results: Of 10 patients, 6 were males and 4 were females. The mean age was 53.5 years old. There were 13 masses analyzed. The mean size of the lesions was 2.3 cm and 53.8% had diameters more than 2 cm. The locations of lesions were right upper lobe (30.8%), right middle lobe (7.7%), right lower lobe (38.5%) and left upper lobe (23.1%). Calcification was found in two lesions. The HRCT findings were spiculated margin (76.9%), lobulated margin (23.1%), smooth margin (7.7%), ground glass opacity (23.1%), concave border (61.5%), polygonal shape (53.8%), air bronchogram (38.5%), pseudocavity (15.4%), pleural tag (30.8%), distortion of vessels (23.1%), satellite lesions (38.5%), and peripheral subpleural lesion (46.2%). Only 7 cases of enhanced study were available and two cases showed enhancement. Of the 10 cases, mediastinal lymphadenopathy was found in 8(80%) cases. The size of the lymph nodes was less than 2 cm in 6 cases and larger than 2 cm in 2 cases. Other associated findings were pleural thickening or effusion (60%), evidence of volume loss (20%), emphysema (40%), and infiltrations(50%).
Conclusion: Many characteristics of Tbc lesion on HRCT mimic reported malignant lesions. Re-evaluation of value of HRCT for controversial lesions is needed.

Keywords: HRCT, Tuberculosis, Pulmonary