Paradoxical reaction to antituberculosis therapy after 6 months of treatment for pulmonary tuberculosis: A case report.

Paradoxical reactions (PRs) to antituberculosis (anti-TB) drugs during treatment are well known phenomena, but a PR presenting as a new pulmonary lesion after completion of treatment is extremely rare, and little is known about the management of such cases. A 44-year-old man was diagnosed with pulmonary TB. His sputum cultures became negative 45 days after the initiation of standard anti-TB treatment. Upon the patient's completion of 6 months of anti-TB therapy, computed tomography revealed a new irregularly shaped mass in the lower left pulmonary lobe. A transbronchial lung biopsy (TBLB) revealed caseous necrosis and granulomatosis surrounded by epithelioid and multinucleated giant cells. Cultures of both the TBLB specimen and bronchoalveolar lavage fluid remained negative for TB. The CT shadow disappeared 6 months later without further administration of anti-TB drugs. Careful observation without therapy may be sufficient for a patient treated for TB who develops a PR upon completion of treatment, if the patient has achieved a bacteriological remission.