Non-invasive bladder cancer is effectively treated with intravesical BCG therapy. The administration of the BCG vaccine is to destroy the neoplastic lesion or prevent further recurrences. The activity of the vaccine involves boosting the immune system through the stimulation of the inflammation in the bladder. Adverse reactions after this immunotherapy are rare.

The aim of the study was to present complications in the form of spinal tuberculosis and serious neurological symptoms that occurred during intravesical BCG immunotherapy for carcinoma of the bladder. The manuscript also describes a method for neurosurgical spinal cord decompression of the thoracic spine.

In the first patient, aged 66, after intravesical BCG therapy for bladder carcinoma, back pain and spastic paralysis of the lower limbs were observed. The MRI and CT revealed destruction of the intervertebral disc and vertebral endplates Th11–Th12. Mycobacterium tuberculosis complex bacilli were cultured from the material obtained by puncture aspiration. In the second patient, aged 35 years, during intravesical BCG immunotherapy for carcinoma of the bladder, girdle thoracic spine pain was observed. The MRI and CT of the spine showed visible lesions characteristic of tuberculosis. Immobilization in a plaster corset and implementation of antituberculous treatment resulted in quick relief of the pain and healing of the tuberculosis focus in the spine.

The cases described in the work are the first documented reports in the Polish literature of spinal tuberculosis which occurred as a complication of intravesical administration of bacilli Calmette–Guérin. The diagnosis was based on the finding of BCG vaccine bacillus with molecular methods or PCR. Full antimycobacterial treatment was implemented.