Letter to the Editor: Tuberculosis of the Spine Masquerading as a Benign Neoplasm

Abstract

To the Editor:

Tuberculosis (TB) is a multisystem and multiorgan disease caused by Mycobacterium tuberculosis infection, and bone and joint system TB accounts for approximately 10% of extrapulmonary tuberculosis, of which 50% occurs in the spine.^1,2 Because of the lack of specific clinical manifestations of spinal TB, the results of laboratory and imaging examinations are difficult to distinguish from spinal tumors, and it is easy to be misdiagnosed. Herein, we report a case of TB of the spine masquerading as a benign neoplasm.

A 50-year-old female sought medical attention because of a one-year history of persistent back soreness. She had no history of TB and related exposures. Physical examination found percussion tenderness in the spinous processes of the T11–L2 vertebral body and paravertebral muscles. Peripheral blood leukocyte count 5.59 × 10⁹/L, neutrophil count 4.15 × 10⁹/L, high-sensitivity C-reactive protein 20.98 mg/L, erythrocyte sedimentation rate 71 mm/h. Magnetic resonance imaging (MRI) showed that the T11–12 vertebral body and some of its appendages were bone-damaged and unevenly signaled, showing mixed signal shadows dominated by long T1 and long T2 signals, and the corresponding soft tissues on the left side of the vertebral body and the left erector spinae muscle were swollen and multiple cystic, clumpy T1W1 hypointensity, and T2W1 showed mixed hyperintensity (Fig. 1).

FIG. 1.

Magnetic resonance imaging (MRI) showed that the T11–12 vertebral body and some of its appendages were bone-damaged and unevenly signaled, showing mixed signal shadows dominated by long T1 and long T2 signals, and the corresponding soft tissues on the left side of the vertebral body and the left erector spinae muscle were swollen and multiple cystic, clumpy T1W1 hypointensity, and T2W1 showed mixed hyperintensity.

Based on the patient's relevant data, it was considered to be bone destruction (T11, T12 vertebral body and intervertebral disc destruction). After consultation, the patient and her family requested surgical treatment. The patient then underwent thoracic discectomy with laminectomy (posterior T11/12 lesion resection + epidural discectomy + spinal decompression + T9–12 pedicle screw fixation). Histopathology of vertebral lesions showed granulomatous inflammation with necrosis, fibrous tissue hyperplasia, and dead bone, and morphology consistent with TB (Fig. 2). X-pert and Mycobacterium tuberculosis culture of bone tissue showed that Mycobacterium tuberculosis was detected and rifampicin resistance. The final diagnosis was spinal RR-TB (T11, T12 vertebral and intervertebral disc destruction). The patient recovered well post-operatively and received regular anti-TB therapy.

FIG. 2.

Histopathology of vertebral lesions showed granulomatous inflammation with necrosis, fibrous tissue hyperplasia, and dead bone, and morphology consistent with tuberculosis (TB).

Previous studies have reported that approximately 67% of spinal TB is related to pulmonary tuberculosis (PTB).³ If the patient has PTB or other extrapulmonary TB, it can be suggestive of the diagnosis. For spinal TB, the traditional gold standard for diagnosis is pathology and culture, but the detection rate is low. It has been proposed that Xpert MTB/RIF of bone tissue has high specificity and sensitivity for the diagnosis of bone TB.⁴ In this case, the X-pert and Mycobacterium tuberculosis culture of bone tissue were positive, which confirmed the pathologic diagnosis of RR-TB of the spine and pointed out the direction for subsequent treatment. Therefore, the definitive diagnosis of spinal TB alone is a difficult point in clinical work, especially to distinguish it from spinal tumors. How to make a non-invasive, efficient and accurate diagnosis in the early stage of the disease is the direction of further exploration in the future.