Polymerase chain reaction in cutaneous tuberculosis: is it a reliable diagnostic method in paraffin-embedded tissues?

Abstract

Background Most cutaneous tuberculosis lesions contain few bacilli, so identification of Mycobacterium tuberculosis in conventional laboratory tests is difficult. In vitro amplification of specific DNA sequences using polymerase chain reaction (PCR) has become a valuable tool in the rapid detection of slow-growing organisms like M. tuberculosis . Aim To investigate the presence of M. tuberculosis DNA in cutaneous tuberculosis. Methods Twenty-two archival biopsy specimens diagnosed as cutaneous tuberculosis were investigated for the presence of M. tuberculosis DNA by PCR. Normal skin samples of 29 healthy patients were used as a control. Results Amplification of the M. tuberculosis DNA was observed in one of the cutaneous tuberculosis specimens and in a healthy control. Conclusion Although PCR is a rapid diagnostic method, fixation procedures may decrease its sensitivity.