Infection with Mycobacterium tuberculosis (TB) is one of the major causes of mortality in developing countries, affecting millions throughout the world ^{1, 2} . TB is primarily a lung disease but can affect almost every organ of the body. The term "extrapulmonary TB" is used to describe a clogged infection in places other than the lung. The most common places are extrapulmonary tuberculosis of the lymph nodes, urinary tract, pleura, bones and joints, meninges and central nervous system, peritonea and other abdominal organs ³ . In a study of 483 patients with pulmonary TB infection in Chile, only 2% of all the cases of tuberculosis infection were associated with skeletal tuberculosis ⁴ . In addition, in the United States, an estimated 10.8% of extra-pulmonary tuberculosis cases were considered skeletal tuberculosis in general, accounting for 2.3% of total tuberculosis statistics ⁵ . Spinal TB, also known as “Pott's disease,” accounts for about 50% of cases of skeletal tuberculosis, and is commonly found in children and adolescents ⁶ .

In this report, we will introduce a patient with a medical history of transitional cell carcinoma (TCC) of the bladder that presented with spinal tuberculosis (Pott's disease).

Skeletal TB refers to the involvement of the bones or joints ⁷ . Forms of skeletal TB include osteomyelitis, spondylitis, and arthritis. The literature on spinal TB shows a wide variation in reported rates of active concomitant pulmonary TB at the time of spinal TB diagnosis ^{8– 10} . In our case, however, pulmonary involvement was absent.

TB spondylitis or Pott’s disease most commonly affects the lower thoracic and upper lumbar vertebras, and less frequently cervical and upper thoracic vertebrae ^{10, 11} . The most common symptom is focal pain, which increases in severity over time, and is sometimes accompanied by muscle spasm. The muscle spasm can extend to other parts of the body. In some cases, it can cause difficulty in gait. ¹² .

The diagnosis of skeletal TB is often delayed and may be difficult. It is made based on culture of tissue ¹³ . But computerized tomography, magnetic resonance imaging, and myelography are all useful diagnostic tools ^{10, 14– 16} . Radiographic findings can be nonspecific; early features may include soft tissue swelling (especially of the anterior portions of the vertebral body) with bone demineralization and preservation of joint surfaces ¹¹ . In our case, because of the seriousness of decreased range of motion of lower extremities, and high clinical susceptibility to Mycobacterium infection, and given that radiological findings were similar to those for patients with TB spondylitis, the process of diagnosis was rapid.

Patients with metastatic TCC of bladder in the bone and liver have poor prognosis ¹⁷ . For this reason, it was important to rule out metastasis in the case of this patient.

Given that vertebrae osteomyelitis has been seen in patients receiving intravesical BCG for the treatment of TCC of the bladder ¹⁸ , the presence of Mycobacterium bovis was expected in the culture sample, but Mycobacterium tuberculosis was confirmed.

In the lesions of the lumbar vertebrae, even if there is another underlying disease, spinal TB should also be considered as a possibility.

Written informed consent was obtained from the patient for the publication of the patient’s clinical details and accompanying images.

All data underlying the results are available as part of the article and no additional source data are required.