Case Presentation: An 88-year-old man presented with fevers, chills, weight loss, and acute confusion. The patient had a history of non invasive high grade papillary urothelial carcinoma of the bladder treated with transurethral resection of bladder tumor and intravesical Bacillus Calmette-Guérin (BCG) therapy. Symptoms occurred one year after completion of BCG therapy. His Physical Examination was unremarkable, except for a fever of 101 degrees Fahrenheit and a boggy enlarged non-tender prostate. Diagnostic workup included a hemoglobin level of 11.2 g/L, hematocrit of 34.3%, platelet count 142 x 109/L, and WBC count of 4.3 x 109/L. His electrolytes were normal but inflammatory markers were elevated. Prostate specific antigen and thyroid stimulating hormone were normal. CT of the abdomen and pelvis revealed no evidence of malignancy. TEE revealed a dilated ascending aorta and severe atheromatous disease of aortic arch. MRI of the brain revealed punctuate enhancing lesions throughout cerebrum and cerebellum, however, cerebrospinal fluid analysis and cultures were normal. PET showed abnormal fluorodeoxyglucose activity at multiple sites along the abdominal aorta and right common iliac artery concerning for infectious etiology. CT of the chest revealed bilateral scattered ground glass opacities. Bronchoscopy and bronchoalveolar lavage were performed. Subsequently, Mycobacterium bovis was isolated both from blood and bronchoalveolar lavage cultures. Rifampin, Isoniazid, Ethambutol, and Pyridoxine were initiated in addition to moxifloxacin for added central nervous system coverage. Treatment led to clinical improvement of fevers and altered mentation as well as radiological improvement.

Discussion: BCG therapy has been long been the mainstay of treatment of superficial bladder cancer. Inflammation and elimination of malignancy occur via local modulation of immune response. Hematuria, fever, nausea, and dysuria may occur post instillation as markers of anti-tumor effect. However, Mycobacterium bovis dissemination due to local trauma or inflammation of the genitourinary tract may cause similar symptoms. Sepsis, pneumonitis, hepatitis, lymphocytic meningitis, bone marrow involvement, and mycotic aneurysms are reported complications in less than 5% of patients. Symptoms may occur days to years after BCG instillation. Due to the protean manifestations, low rates of tissue and cerebrospinal fluid culture positivity, and lack of consensus diagnostic guidelines, diagnosis of disseminated Mycobacterium bovis is a clinical challenge.

Conclusions: We report a patient with widely disseminated Mycobacterium bovis infection pneumonitis as well as a presumed mycotic aneurysm and central nervous system involvement. Systemic symptoms following BCG instillation should prompt early evaluation for this lethal yet treatable condition. Increased awareness and high index of suspicion leading to early diagnosis would decrease morbidity and mortality associated with this disease.