Bacillus Calmette-Guérin (BCG)-Induced Pneumonitis: A Case Report.

Bladder cancer is the second most common genitourinary (GU) malignancy worldwide. Treatment involves early cystectomy and intravesical Bacillus Calmette-Guérin (BCG), which is effective for T1 high-grade tumors and carcinoma in situ (CIS) but can cause significant side effects, including chemical and bacterial cystitis, hematuria, incontinence, pneumonitis, malaise, fever, and sepsis. We present the case of a 47-year-old male with transitional cell carcinoma (TCC, G3 pTa) treated with transurethral resection of bladder tumor (TURBT) who developed a fever and non-productive cough after BCG injections.