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

Infection with (TB) is one of the Background Mycobacterium tuberculosis major causes of mortality in developing countries. TB is primarily a lung disease, but can affect almost every organ of the body. Skeletal TB involves the bones or joints. 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). The patient was a 74-year-old man with medical history of TCC Case Report: of the bladder who had come to hospital due to severe weakness and sprains of lower extremities. Other symptoms noted by the patient included anorexia, weight loss (of 5 kg), and night sweats, but he did not complain of fever, coughs or respiratory symptoms. The lab data were as follows: WBC, 16/9*10 ; ESR, 88 mm/hr; CRP, 78mg/dl. Radiology findings revealed degenerative process in the L2-L3 lumbar vertebrae and disk. PCR and sample tissue culture results showed the presence of Mycobacterium tuberculosis. In the lesions of the lumbar vertebrae, even if there is another Conclusion: underlying disease, spinal TB should also be considered as a possibility. Furthermore, in patients with any type of cancer, any other organ conflict is not considered as metastasis, and tissue sampling should be provided because a change in the type of disease can influence prognosis.

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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 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 extrapulmonary 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).

Case report Patient information
The patient was a 74-year-old man from Yasouj city (Southwest of Iran) with a medical history of chronic kidney disease, TCC of the bladder, who was on BCG (Bacille Calmette-Guérin) chemotherapy, and deep vein thrombosis, who had come to hospital due to severe weakness and sprains of lower extremities. The patient noted that the weakness and numbness of the lower extremities were progressive and became worse at night. During this period, the patient had not undergone any further diagnosis, and controlled his pain with acetaminophen. Other symptoms that the patient noted was anorexia, weight loss of 5 kg, and night sweats, but he did not complain of fever, cough and respiratory symptoms.

Clinical findings
During the clinical examination, tenderness of the lumbar spine was accompanied by a decrease in the range of motion (ROM) from 2 / 5 of right lower extremities and 3 / 5 of right lower extremities, in addition to positive reverse SLR (Straight Leg Raise) test.

Diagnostic assessment
The patient's test results are presented in Table 1.
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).
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.

Follow-up and outcomes
Currently, after 4 months, the patient receives anti-TB drugs under the supervision of the Yasouj Health Center, and has not noted any evidences of weakness or night sweating. ROM of both lower extremities is 4/5. After completion of treatment, the patient will undergo a follow-up period under the supervision of the Neurosurgery Department.

Discussion
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 12 . 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.

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.

Competing interests
No competing interests were disclosed.

Grant information
The author(s) declared that no grants were involved in supporting this work.

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Competing Interests: No competing interests were disclosed.
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