DISCUSSION
Intravesical instillation of BCG remains the most adequate therapy for superficial urothelial carcinoma of the bladder, ensuring cure rates of up to 80%. It is thought that BCG produce a local immune response which results in the production of proinflammatory cytokines and influx of leucocytes, ultimately result to lysis of tumor cells. Its side effects may include urinary frequency (71%), cystitis (67%), fever (25%) and hematuria (23%), that in most cases resolve spontaneously within 48h and can be managed symptomatically [4]. Other more serious side effects may be granulomatous hepatitis and pneumonitis occurring in 0.7% of the cases, sepsis in 0.4%, arthralgias in 0.5% and cytopenias in 0.1%. Less than 1% of the patients evolved with disseminated BCG infection [5]. The exact pathogenesis underlying the systemic infection occurring after instillation of intravesicular BCG is not fully understood. It is thought that local inflammatory process results in disruption of the uroepithelial bladder cells thereby allowing organisms to disseminate hematogenously or via the lymphatic system. It has also been reported that BCG can persist in the bladder and spread hours to months, and even years, following the completion of the therapy[6]. Until the date, was not possible to identified risk factors associated to disseminated BCG infection, including the time from TUR, the number of BCG instillations or associated immunosuppression [7]. Disseminated BCG should be suspected in every patient with previous intravesical BCG therapy that presents with fever and/or organ disfunction, with or without symptoms in the genitourinary tract. However, establishing the diagnosis is difficult: regardless of a history of BCG exposure, all other causes of fever must be excluded, although, clinical improvement after treatment initiation reinforces the diagnosis. Histologic examination of biopsies of different possible involved organ usually demonstrates granulomatous inflammation but only the microbiologic tests confirm the diagnosis [7]. Disseminated BCG infection should be treated with antituberculosis therapy. The most common regimen consisted of isoniazid, rifampin and ethambutol. Corticosteroid use is not consensual and is usually reserved for severe cases that evolve with respiratory failure [7].