A 19-year-old male patient was admitted to Subei People's Hospital of Jiangsu (Yangzhou, China) on 5th September 2011 with a 2 month history of recurrent fever and intermittent thoracic back pain. The recurrent fever did not occur at specific times and the temperature did not exceed 38.0 C. The patient also reported limited mobility, decreased appetite and weight loss, but did not experience chills or night sweats. There was no history of exposure to TB or of a chronic cough. The patient presented a normal general physical condition, with a body temperature of 37.3 C. A physical examination revealed slight tenderness over the mid-thoracic spine, lumbar spine and left sacroiliac joint. No paraspinal swelling or spasms were observed, while the sensation, muscle strength and muscle tone of the lower extremities were normal. Laboratory examinations showed a normal white blood cell count [6.6x109/l; normal range (NR), 3.5-9.5x109/l] and normal levels of hemoglobin (120 g/l; NR, 110-160 g/l), human leukocyte antigen-B27 (78; NR, 0-145) and rheumatoid factor (5.0 IU/ml; NR, 0-14 IU/ml). In addition, tests for autoantibodies, immunoglobulin, TB antibodies and tumor-associated antigens were negative. The erythrocyte sedimentation rate (ESR) was 75 mm/h, which was higher than the normal range (0-15 mm/h), and the C-reactive protein level was normal (10 mg/l; NR, 0-10 mg/l). Human immunodeficiency virus (HIV) and purified protein derivative (PPD) tests were negative.
Further imaging analysis showed normal abdominal ultrasound findings and X-rays of the chest, thorax, lumbosacral region and pelvis. CT reconstruction of the sacroiliac joint indicated multiple round hypodense lesions with a hyperdense center, as well as some cortical destruction and soft tissue swelling in the lumbar and sacral vertebrae, and the left ilium regions (Fig. 1). A contrast-enhanced CT scan of the chest, with Omnipaque  (1.5 ml/kg; GE Healthcare Life Sciences, Shanghai, China) as the contrast enhancement agent, demonstrated an irregular patchy hypodense signal in the left lung lobe with a patchy translucent shadow inside, which was enhanced heterogeneously (Fig. 2). A chest CT scan showed multiple round hypodense lesions with higher central density in the thoracic vertebrae, ribs and sternum (Fig. 3). Furthermore, a CT reconstruction of the thoracic spine indicated bone destruction with partial cortical perforation (Fig. 4). MRI scans revealed multiple round ring signal shadows with a continuous finishing border from Th12 to S4 in the anterior, central and posterior elements, but not in the end plate. In addition, sagittal T1-weighted and T2-weighted images revealed a hypodense signal in the internal of the lesions and a slightly hypodense signal in the peripheral region, which was accompanied by soft tissue swelling, with visible ring enhancement and soft tissue enhancement following intravenous administration of gadolinium (GE Healthcare Life Sciences) (Fig. 5).
Based on the symptoms and all the aforementioned examinations, lymphoma, metastatic disease or bone TB were suspected. Since the CT and MRI findings did not allow for a final diagnosis, a CT-guided biopsy from the lesions in the Th7 vertebral, left iliac and adjacent left lung using an 8-gauge needle (Yangzhou City Jiangzhou Medical Instrument Co., Ltd., Yangzhou, China) was performed to confirm the diagnosis. However, no evidence of granulomata, necrosis, lymphoma or other malignancies was observed. Subsequently, an open biopsy was performed in order to establish a pathological diagnosis, during which fish-shaped soft tissue adhesion with surrounding tissues under the lamina of Th7 and local sequestrum formation were observed. Part of the surrounding soft tissues and bone lesions were removed for pathological examination and culturing. Upon hematoxylin and eosin staining of the tissue and visualization under the Olympus BX43 microscope (Olympus Corporation, Tokyo, Japan), a large amount of necrosis, epithelioid cells, Langerhans giant cells and dead bone were observed (Fig. 6), which are characteristics of TB. The results of Acid-Fast Bacilli culturing (Sinobest Biotech Co., Ltd., Shanghai, China) were negative; however, a polymerase chain reaction performed by Shanghai Genechem Co., Ltd. (Shanghai, China) was positive for TB. Based on these observations, a diagnosis of multifocal skeletal TB was established.
The patient was discharged from the hospital on 27th September 2011. Postoperatively, the patient was administered a common quartet anti-TB chemotherapy regimen, including isoniazid (300 mg/day), rifampicin (600 mg/day), pyrazinamide (750 mg/day) and ethambutol (750 mg/day; all Shanghai Sine Pharmaceutical Co., Ltd., Shanghai, China) for 12 months. The patient's symptoms greatly improved after 1 month of anti-TB treatment and the ESR decreased to 65 mm/h. At the final follow-up on 11th March 2013, the patient was free of symptoms and the ESR had decreased to the normal value. MRI scans obtained following 20 months of anti-TB therapy showed that the range of the extensive abnormal signal intensity had become smaller, as compared with that before anti-TB treatment was initiated (Fig. 7).
Informed consent was obtained from the patient's family prior to the publication of the present case.
Contrast-enhanced chest computed tomography scans showing irregular patchy hypodense change in the left lung lobe with patchy translucent shadow inside.