Abstract
Intravesical bacillus Calmette-Guérin (BCG) is used for urothelial carcinoma. Systemic side effects are rare and commonly include organ involvement but rarely include bone marrow. We describe a patient who had received intravesical BCG and presented shortly afterwards with constitutional symptoms. Initial work-up revealed pancytopenia and immune haemolysis. He was presumptively diagnosed with systemic BCG infection and secondary warm autoimmune haemolytic anaemia. Isoniazid, rifampin and ethambutol was started. The bone marrow biopsy revealed granulomas. Within 6 weeks of treatment, the patient's clinic and laboratory results were dramatically improved. A high level of suspicion is crucial for diagnosis and treatment. LEARNING POINTS: Systemic bacillus Calmette-Guérin (BCG) infection following intravesical BCG instillation is a rare but serious consequence. A high level of suspicion and scrutiny of history is of paramount importance for diagnosis.Autoimmune haemolytic anaemia secondary to systemic BCG infection is even rarer.Autoimmune haemolytic anaemia resolution was in parallel with improvement in systemic BCG infection.