Histopathology of Disseminated Mycobacterium bovis Infection Complicating Intravesical BCG Immunotherapy for Urothelial Carcinoma

Abstract

Intravesical instillation of Bacillus Calmette-Guérin (BCG) is a mainstay of adjunctive therapy for superficial bladder cancer. Disseminated BCG infection ("BCG-osis") after this therapy is rare and potentially life-threatening; only isolated case reports detail the histopathologic findings thereof, few of which had a diagnosis confirmed by molecular testing. We report 3 additional cases of BCG-osis complicating BCG therapy, all confirmed by cultures and molecular assays, including the first cases of wedge biopsy-confirmed BCG pneumonia and BCG olecranon bursitis. When suggested by a relevant clinical history, recognition of randomly distributed granulomas in any organ should prompt consideration of BCG-osis and liberal performance of AFB stains, aided by targeted molecular assays. Physicians should maintain a high index of suspicion when miliary infiltrates arise after intravesical BCG instillation, and close multidisciplinary communication is essential. Pathologist awareness of this rare cause of granulomatous inflammation aids recognition of BCG-osis and facilitates prompt initiation of antimycobacterial therapy.

Pan and Core Genome Analysis of 183 Mycobacterium tuberculosis Strains Revealed a High Inter-Species Diversity among the Human Adapted Strains

“…In 2007, the WHO stopped recommending the use of BCG vaccination for HIV infected children due to the deleterious risk of BCG disseminated infection or BCGosis, which could be engendered by its use [ 11 ]. Recently, it showed also the same effect on cancerous patients treated with or without intravesical instillation, causing pulmonary TB, which is sometimes associated with extrapulmonary manifestations and very serious complications [ 38 , 39 ].…”

Mycobacterium bovis hip bursitis in a lung transplant recipient

“…Our patient had an unusual presentation of extrapulmonary TB, localized to the hip bursa. A few reports of M. bovis osteoarticular infection have been published , including BCG olecranon bursitis in a patient receiving intravesicular BCG therapy for urothelial carcinoma , occupational wrist tenosynovitis , and knee infection . Our case patient had an unusual site of reactivation, as she had no prior hip trauma or arthritis.…”

Infection of an axillo-bifemoral bypass graft following intravesical bacillus Calmette–Guerin (BCG) immunotherapy for urothelial cancer due to Mycobacterium bovis and Staphylococcus aureus

“…BCG is a live attenuated strain of Mycobacterium bovis that has become the treatment of choice in patients with superficial urothelial cancer [1]. Intravesical BCG therapy reduces disease progression, the need for cystectomy, and prolongs survival [2].…”