Abstract: Mycobacterium tuberculosis DNA was detected by polymerase chain reaction(PCR) from 53 samples of paraffin embedded tissues which were clinically or pathologically diagnosed as cutaneous tuberculosis (CT) or nodular dermatoses (NDs). The positive identification rates by PCR in clinically diagnosed CT and NDs patients were 45% and 47%, respectively. The consistency in diagnosis between PCR and the clinical diagnosis was 47%. The positive identification rates by PCR in pathologically diagnosed CT and NDs patinets were 42% and 53%,respectively. The consistency in diagnosis between PCR and the pathological diagnosis was 43%. These results indicate that it is difficult to successfully differentiate between cutaneous tuberculosis and nodular dermatoses either clinically or pathologically, and that the PCRmethod is useful to detect pathogenic evidence in the lesions of tuberculous infection.

Key words: Tuberculosis,cutaneous, Nodular dermatoses, Polymerase chain reaction