Successful diagnosis of tuberculous lymphadenitis by loop-mediated isothermal amplification of cutaneous samples from an ulcerated surface lesion: A case report

Introduction. Tuberculous lymphadenitis is the most frequent form of extrapulmonary tuberculous. Although nucleic acid amplification assays such as polymerase chain reaction have recently become mainstream techniques for diagnosing tuberculous lymphadenitis, they are still not routinely performed in developing countries because of their high costs and complicated procedures. Case presentation. We describe a case of tuberculous lymphadenitis in a 79-year-old Japanese man who had been on continuous hemodialysis for end-stage renal disease. We employed loop-mediated isothermal amplification and the procedure for ultrarapid extraction to develop a fast and easy-to-perform procedure for diagnosing tuberculous lymphadenitis. Conclusions: The commercially available loop-mediated isothermal amplification assay kit and a rapid purification procedure enabled us to identify and amplify a Mycobacterium tuberculosis-specific gene within just 1.5 hours.