Case Report: Suspicions of metastasis in a patient with transitional cell carcinoma were revealed to be spinal tuberculosis

Introduction

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 organs³. 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 tuberculosis⁴. 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 statistics⁵. Spinal TB, also known as “Pott's disease,” accounts for about 50% of cases of skeletal tuberculosis, and is commonly found in children and adolescents⁶.

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).

Case report

Diagnostic assessment

The patient’s test results are presented in Table 1.

Table 1. Laboratory results for the patient on admission.

		Normal range
White blood cell	16/8 *103 cells/mcl	5–10 *103 cells/mcl
Hemoglobin	9/5 gm/dl	14–16 gm/dl
Mean cell volume	77 F/L	75–92 F/L
Platelet	324 *103 cell/mcl	150–450 cell/mcl
Erythrocyte Sedimentation Rate	88 mm/hr	<20 mm/hr
C-reactive protein 3-Human immunodeficiency virus	78 mg/dl	<10 mg/dl
Creatinine	1.7 mg/dl	0.6–1.2 mg/dl
Anti-HIV 3 antibody	Negative	NA

In the CT scan, hypo-dense mass of size 140 × 44 × 44 mm in paravertebral space L2 was observed, with destruction of the right and left facet joint and spinous process of L2, and destruction of intervertebral disk of the L2 - L3 (Figure 1). In the MRI, an increase in the signal of the L2 and L3 vertebral bodies was observed, along with the destruction of the anterior plate and the reduction of the articular space. In the same area, a lesion was observed with a moderate signal on the anterior longitudinal ligament and posterior longitudinal ligament, and a complete loss of CSF (Figure 2).

Figure 1. CT scan of spine showed a hypo-dense mass of size 140 × 44 × 44 mm in paravertebral space L2, and destruction vertebral body of L2 and destruction of intervertebral disk of the L2 - L3.

Figure 2. MRI of the spine revealed an increase in the signal of the L2 and L3 vertebral bodies, along with the destruction of the anterior plate and the reduction of the articular space.

In the same area, complete loss of CSF can be seen.

For accurate diagnosis, the patient underwent ultrasound-guided biopsy, and the samples were sent to the lab for PCR, culture and histological examination. In the sampling report, PCR confirmed infection with Mycobacterium tuberculosis. Furthermore, the tissue culture was also found to be positive for Mycobacterium tuberculosis.

Discussion

Skeletal TB refers to the involvement of the bones or joints⁷. 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 tissue¹³. 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 surfaces¹¹. 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 prognosis¹⁷. 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 bladder¹⁸, the presence of Mycobacterium bovis was expected in the culture sample, but Mycobacterium tuberculosis was confirmed.

Conclusion

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

Consent

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

Data availability

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