Identification of Atypical Mycobacterium with the Polymerase Chain Reaction in Tuberculous Lymphadenitis

ABSTRACT

Tuberculous lymphadenitis is easily mistaken for an infection by only mycobacterium tuberculosis. However, many cases reveal atypical mycobacterium. Treatment of atypical mycobacterium differs from that of M. tuberculosis and M. bovis. Usual anti-tuberculous medication is the response to M. tuberculosis and M. bovis, but not to atypical mycobacterium. Excision and antibiotic therapy is the known treatment of choice for atypical mycobacterium. We used the polymerase chain reaction(PCR) for differential diagnosis of tuberculosis from lymphadenitis, and by using PCR we were able to differentiate the infecting organism as typical or atypical mycobacterium. We excised 50 case of cervical lymphadenitis, and PCR was done with Primer I(IS6110), which is specific for M. tuberculosis and M. bovis, and with Primer II(65 KDa Ag), which covers all mycobacterium species. The results obtained by PCR were compared with the pathologic results(control): sensitivity 81.8%, specificity 88.9%, false positive ratio 11.1%, false negative ratio 18.2%, typical mycobacterium 45.5%, and atypical mycobacterium 45.5%. These findings suggest that PCR is a good diagnostic tool for the early detection of tuberculous lymphadenitis and for differentiation of mycobacteria in cervical lymphadenitis.