Transbronchial Biopsy(TBBx) negative in patients with positive Bronchoalveolar lavage(bal) for Pneumocystis Carinii Pneumonia(PCP)

PURPOSE: The purpose of our study was to review those cases with BAL positive and TBBx negative for PCP and evaluate the factors that may predispose to have a negative TBBx. METHODS: A retrospective chart review of all patients with TBBx negative and BAL positive for PCP was done during the period between 1993 to 1996. This group was compared with a randomly selected group of patients with TBBx and BAL positive during the same period of time. Chest roentgenographic findings, site of biopsy, size and number of specimens obtained were reviewed. RESULTS: A total of 13 out of 88 patients had TBBx negative. These group was compared with 43 randomly assigned patients with TBBx positive. In 4 of the 13 cases with TBBx negative no alveolar tissue was obtained. TBBx neg. pos. CXR Bilateral 13 40 Localized/Normal 0/0 3/0 TBBx:Right lower lobe 8(62%) 24(56%) Right upper lobe 1(7%) 5(12%) Right middle lobe 0 1(2%) Left lower lobe 2(15%) 7(16%) Left upper lobe 2(15%) 6(14%) Average # specimens 2.7 3.2 Median size of 0.18 0.25 spec(cm) CONCLUSION: There was a tendency for the patients with TBBx negative to have less and smaller specimens. Comparison with patients with positive BAL and TBBx did not show any significant difference in radiologic findings and site of TBBx. CLINICAL IMPLICATIONS: If TBBx is performed to increase the yield for PCP the operator should obtain at least 3 or more large specimens to decrease the chances of having a negative TBBx.