A Rare Case Seen in a Patient with Intravesical Bacillus Calmette-Guerin (BCG) Intolerance: Autoimmune Myopathy

Aim: We present a case of autoimmune myopathy observed in a patient who developed intolerance to intravesical Bacillus Calmette-Guerin (BCG), which is used in the treatment of non-muscle invasive bladder cancer. Case: Intravesical BCG, which is used for the treatment of non-muscle invasive bladder cancer, probably effects by increasing autoimmunity in the bladder. This increased autoimmunity sometimes causes local or systemic reactions. In this case report, we would like to present a 61-year-old male patient who developed intolerance while taking the first dose of maintenance BCG, and then on-going treatment was stopped. The patient had convulsive painful cramps and muscle twitches in the left quadriceps femoris region one month later BCG intolerance. When the patient’s anamnesis, electromyography (EMG) results, elevated Creatine Kinase value and other laboratory data were evaluated together, BCG triggered autoimmune myopathy was considered. Therefore, steroid treatment was started and the patient recovered seven weeks later. This is a rare case of autoimmune myopathy in a patient who received intravesical BCG therapy for a bladder tumor. Conclusion: The case of BCG-associated autoimmune myopathy is extremely rare. When this situation is suspected, it is beneficial to start steroid treatment without delay.