[Bacteriological examination on needle biopsy specimens of cavity and tuberculoma after a short course chemotherapy in initially sputum positive pulmonary tuberculosis patients].

Objective: To evaluate the therapeutic effect of a short course chemotherapy on initially sputum positive cavitary pulmonary tuberculosis or tuberculoma by bacteriological examination of specimens through percutaneous lung biopsy after the chemotherapy.

Methods: Eighty-three cases of initially sputum positive pulmonary tuberculosis with cavities or tuberculoma were included from Jan. 2002 and May. 2004. The patients finished a course of chemotherapy (2HREZ/4HR), and the sputum was converted to smear-negative and culture-negative, but cavities or tuberculoma remained on the chest X-ray. Lung specimens were obtained from the wall or content of the cavity or from the tuberculoma by CT-guided percutaneous lung biopsy for bacteriological examination within one month after the course.

Results: All the needle biopsy specimens were smeared and cultured for Mycobacterium tuberculosis. Eight cases (8/83, 9.6%) showed positive results: 3 were smear-positive and culture-positive, and 5 smear-negative but culture-positive. Drug susceptibility test showed that 7 of them were drug-sensitive and the remaining 1 was resistant to rifampin and isoniazid. After follow-up of 24 months, 6 of them converted to sputum smear-positive.

Conclusion: Our study showed that 90.4% (75/83) of the tuberculosis cases achieved real bacteriological negative result on biopsies after a short course chemotherapy, and the bacteriological positive cases on biopsy experienced 75.0% (6/8) sputum bacteriological recurrence. The result suggests that the evaluation criteria with sputum on therapeutic effect of pulmonary tuberculosis needs to be reassessed.