Presumed Simultaneous Intraocular and Extraocular BCG-osis as a Complication of Intravesical Bacillus Calmette-Guérin Treatment for Non-Muscle-Invasive Bladder Cancer: A Case Report.

Bacillus Calmette-Guérin (BCG) is a live attenuated vaccine that is used as an adjunct following transurethral resection of bladder tumour (TURBT). This treatment is highly effective at reducing the recurrence and progression of the disease, but has a risk of disseminated tuberculosis (TB) infection. Rarely, this can result in ocular involvement, which can manifest as an extraocular granulomatous lesion external to the eye, or intraocular inflammation. This case report presents the simultaneous manifestations of both intraocular and extraocular complications in a 64-year-old gentleman with disseminated TB after receiving BCG immunotherapy with bladder cancer. Although intraocular sampling did not yield positive results for mycobacterial infection, the patient's ocular disease had responded well to anti-tubercular therapy and topical steroids, which led to a presumed diagnosis of ocular TB from the disseminated BCG infection. In addition to demonstrating a rare ocular complication following BCG treatment, it highlights the difficulties in the diagnosis of ocular TB due to low diagnostic yield and the importance of clinicians having a high index of suspicion to diagnose and treat the disease.