Case report of tuberculoid granuloma in scrotal skin after bacillus Calmette–Guérin (BCG) therapy

Abstract

We report the case of a 74-year-old man who presented with a tuberculoid granuloma in the scrotal skin after bacillus Calmette–Guérin (BCG) therapy. The patient was treated for bladder cancer with transurethral resection of the bladder tumor, MVAC (methotrexate, vinblastine, adriamycin and cisplatin) chemotherapy, and BCG therapy from 2008 to 2015. After the second BCG treatment, the patient found a tubercle in the right scrotal skin and visited the Department of Dermatology at our hospital. A Mycobacterium sp. was isolated from the biopsy sample. PCR and immunochromatography revealed that the isolated Mycobacterium sp. belonged to the Mycobacterium tuberculosis complex. However, it is necessary to distinguish M. tuberculosis from M. bovis BCG because the treatment methods and infection control measures for the two organisms differ. We performed another PCR, which showed that the M. tuberculosis complex strain was M. bovis BCG. Most strains of the M. tuberculosis complex, which usually infect humans, are identified as M. tuberculosis; and infection by M. bovis BCG is quite rare. However, we should consider M. bovis BCG in cases of urological infection in patients with bladder cancer.