A 58-year-old man was admitted to our Tuberculosis (TB) Department with fever, moderate cough, night sweats, weight loss of 10 kg, and loss of appetite. The patient had been receiving intravesical Bacillus Calmette-Guérin (BCG) instillations for 9 months as immunotherapy for bladder cancer. The high-grade superficial (pT1) urothelial cancer was diagnosed almost 1 year before admission. The only adverse effect of BCG treatment was intermittent myalgia. The patient had no contact with any person with TB, did not smoke, and his HIV status was negative. Chest X-ray was not performed prior to treatment initiation. Chest X-ray on admission revealed multiple, tiny, uniform nodules diffusely and evenly distributed in the lungs (Figure 1A and 1B). Miliary TB was suggested as a differential diagnosis. Computed tomography (CT) of the chest confirmed numerous nodules, measuring 1–2 mm, evenly disseminated throughout the lungs (Figure 1C–1E). Sputum smear was negative for acid-fast bacilli (AFB), but Mycobacterium tuberculosis complex DNA was confirmed using the GeneXpert MTB/RIF test (Cepheid, Sunnyvale, California, United States). The strain was deemed rifampicin-sensitive, as no mutation was found in the rpoB gene. Due to increased alanine transaminase (ALT) level (171 IU/l, reference range 5–41 IU/l), a less hepatotoxic regimen was chosen. Anti-TB treatment (ATT) with isoniazid, ethambutol, and streptomycin was initiated. After a gradual decrease in ALT (77 IU/l), rifampicin was introduced and streptomycin was withdrawn. After 25 days, M. bovis was cultured in the sputum, and identified with the Mycobacteria growth indicator tube. Drug susceptibility testing showed sensitivity to all first-line drugs except pyrazinamide. After 14 days, urine culture was positive for M. bovis and blood culture was negative for AFB. ATT tolerance was poor, with a loss of appetite and a transient increase in liver enzyme levels. The patient condition gradually improved, with resolution of fever and night sweats. Subsequent sputum specimens and bronchial washings were smear- and culture-negative for AFB. After completion of intensive ATT phase, the patient was discharged with close follow-up. Isoniazid and rifampicin combination was used during the maintenance phase.

Figure 1. A – chest X-ray, posterior-anterior view, multiple, small, evenly distributed nodules visible in both lungs; B – chest X-ray, lateral view; C – computed tomography (CT) of the chest showing small nodules measuring 1–2 mm equally scattered in the upper lobes; D – chest CT showing small nodules distributed at the level of the middle lobe; E – chest CT showing tiny nodules at the level of the basal segments

Intravesical BCG therapy is an effective and widely used treatment for superficial bladder carcinoma. Although treatment with BCG is well tolerated by over 95% of patients, systemic dissemination, such as BCGitis, has occasionally been described. The most common minor side effect is cystitis (26%).1 Pulmonary involvement is very rare (0.3%–0.7%).2 Miliary TB refers to widespread dissemination of TB via hematogenous spread, which occurs in 2%–6% of primary TB cases.3 BCG acts against nonmuscle-invasive bladder cancer mainly by stimulating nonspecific immune response and a torrent of Th-1 cytokines including interferon γ.4 Adverse effects, known as BCGitis, are associated with fever and interstitial or micronodular patterns on chest X-ray or CT.1 This complication has been overwhelmingly reported in men. This may be explained by higher incidence of bladder cancer in men and more common traumatic catheterization, which may provide entry for systemic BCG spread.5 Although complications of BCG therapy are rare, they should be considered when treating patients with bladder cancer.