MILIARY PNEUMONITIS AND INTRAVESICULAR BACILLUS CALMETTE-GUERIN TREATMENT

Abstract

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Bacillus Calmette-Guérin (BCG) is a live attenuated strain of the aerobic bacterium Mycobacterium bovis. Although the mechanism of action by which intravesical BCG elicits anti-tumorigenicity remains elusive, it is a mainstay adjunct treatment of superficial bladder cancer. Non-infectious symptoms including dysuria, hematuria, and fevers are experienced in ~85% of individuals treated. Disseminated mycoplasma infections are reported in less than 5% of patients administered this intravesicular regimen. Most of these infections involve genitourinary structures, but rarely BCG-associated pneumonitis can occur. CASE PRESENTATION: A 59 year-old gentleman presented to urology with gross hematuria. Cystoscopy and biopsy revealed carcinoma in situ with a poorly differentiated transitional cell carcinoma. Transurethral resection of the tumor was performed followed by induction and maintenance therapy with monthly treatments of intravesicular BCG. The patient initially tolerated the BCG treatments quite well, but after two treatment cycles developed an unexplained cough and dyspnea with associated night sweats. A seven-day course of levofloxacin was prescribed for empiric treatment of presumed community acquired pneumonia (CAP). Unfortunately, the patient's symptomatology was recalcitrant to CAP therapy. A high-resolution CT of the chest was performed which demonstrated miliary tuberculosis. Tuberculin skin testing prior to the initiation of BCG was found to be negative. As a guidance counselor, he worked alongside students and fellow faculty at a local high school. He had no recent international travel, prior incarceration, or any other risk factors associated with TB. The decision was made to administer isoniazid and rifampin for treatment of miliary pneumonitis found to be Mycobacterium bovis in origin. The patient's symptomatology resolved following a six-month course the aforementioned regimen. Follow up imaging demonstrated improvement of the previously visualized ground glass opacities in addition to three subcentimeter pulmonary nodules remained. Surveillance imaging after an additional six months showed resolution of the ground glass opacities and pulmonary nodule stability. DISCUSSION: Pulmonary Mycobacterium dissemination is a rare yet grave complication of intravesicular BCG used for the treatment of superficial bladder cancer. The recognition and differentiation of BCG-associated pneumonitis from CAP and Mycobacterium tuberculosis is essential for appropriate pharmacologic intervention, especially since Mycobacterium bovis is resistant to some traditional Mycobacterium drugs. CONCLUSIONS: This case explores the critical features involved in the diagnosis and treatment of BCG-associated miliary pneumonitis. REFERENCE #1: Lamm DL. Complications of bacillus Calmette-Guérin immunotherapy. Urol Clin North Am. 1992 Aug;19(3):565-72. PMID: 1636240. REFERENCE #2: Ghandi NM, Morales A, Lamm DL. Bacillus Clamette-Gurin immunotherapy for genitourinary cancer. BJU int. 2013 Aug;112(3):288-97. doi: 10.1111/j.1464-410X.2012.11754.x. Epub 2013 Mar 20. PMID: 23517232 REFERENCE #3: Sylvester RJ, van der Meijden AP, Witjes JA, Kurth K. BCG versus chemotherapy for the intravescal treatment of patients with carcinoma in situ of the bladder: a meta-analysis of the published results of randomized clinical trials. J Urol. 2005 Jul;174(1):86-91; discussion 91-2. doi: 10.1097/01.ju.0000162059.64886.1c. PMID: 15947584 DISCLOSURES: No relevant relationships by Paul Dugdale, source=Web Response No relevant relationships by Daniel Santone, source=Web Response