Tuberculosis miliar con diseminación hematógena posterior a instilaciones de BCG intravesical: reporte de un caso

Miliary tuberculosis after intravesical immunotherapy with bacillus Calmette-Guerin (BCG) is rare. A few systemic complications associated with intravesical BCG instillations have been reported in the literature. In this case report, we present a patient with low-grade urothelial bladder cancer who presented clinical manifestations compatible with tuberculosis 4 hours after the last instillation of BCG as immunotherapy treatment for his bladder cancer. Consequently, a systematic approach was performed, finding micronodular infiltrates of random distribution in thoracic images suggestive of a Miliary pattern. The patient started anti-tuberculous treatment at the decision of an interdisciplinary board. Among the tests carried out, it was found that the endoscopic flexible fiberoptic bronchoscopy did not present alterations, the stains for AFB (acid-fast bacilli) in bronchoalveolar lavage were negative, as was the Gnexpert for Tuberculosis and culture. However, due to the symptoms and relevant risk factors, it was decided to perform wedge resection by thoracoscopy of the middle lobe, revealing a necrotizing granulomatous process whose histological appearance favored infectious etiology. The patient was diagnosed with miliary tuberculosis because of the symptoms presented, compatible radiology, biopsy findings, and clinical improvement, considering the antituberculosis treatment established. This article describes a case of miliary tuberculosis hematogenous spread in a patient who had previously received intravesical BCG instillations for the treatment of urothelial bladder cancer. Prompt treatment saves lives by avoiding a fatal outcome in these patients.