Reversible roentgenographic progression in the initial treatment of pulmonary tuberculosis

This report concerns 7 patients who developed progressive pulmonary infiltrates during initial treatment of pulmonary tuberculosis. These new areas evolved within weeks after initiation of therapy, they were not usually at the site of the original lesion, and they were noncavitary in nature. At the time of their appearance there was evidence of clinical improvement, the original lesions were unchanged or showed some radiographic improvement, and the results of sputum cultures were positive with organisms sensitive in vitro to the drugs being administered. There was no indication of any other etiology except tuberculosis for the progression. There were no other signs of failure of the drug regimen. With continuation of the initial chemotherapy, sputum conversion occurred and the radiographic response was excellent, with the areas of progression and the original lesions demonstrating resolution or stability.