Medical case: Spinal cord compression caused by tophus in thoracic vertebral canal

General information:

Male, 27 years old

Chief complaint:

Lower extremities weakness for 1 week, 1 week before hospitalization, lower extremities strength progressive weakness, activity limitation, inability to walk when hospitalization, no incontinence or retention.

Past medical history:

Gout for 4 years, denial of trauma and cancer history

Physical examination: 

Fatness, body weight of about 110 kg, body mass index (BMI) 32.14, consciousness, spine without scoliosis deformity, palpable multiple subcutaneous nodules in insteps, slightly red local skin, hardness, no significant tenderness, upper limbs muscle strength gradeⅤ, lower limbs muscle strength grade Ⅲ, superficial sensation weakness below the umbilical level, bilateral Babinski sign (+). 

Imaging examination:

Bipedal CT: multiple near round nodules in subcutaneous soft tissues of proximal 1st to 5th metatarsa prompt tophus.

Thoracic CT: space occupying lesions inside and outside the spinal canal at T9 - 10 level, extension through the intervertebral foramens, worse left side (Figure 1A); 

Thoracic MRI: oval space occupying lesions with equisignal T1 and equisignal T2 at T9 - 10 level of the spinal canal, uneven enhancement, unclear boundaries, spinal cord compression (Figure 1B, Figure 1C).

SPECT: tracer abnormal concentration areas at T9 -10 level, no obvious abnormal tracer concentration areas or defect areas in the rest of the bones (Figure 1D).

Figure 1 results of imaging

A: CT scan results showing the space occupying lesions extension through the intervertebral foramens, worse left side, secondary spinal canal stenosis.

B: MRI showing space occupying lesions with equisignal T1 and equisignal T2 at T9 - 10 level of the spinal canal

C: enhanced MRI showing uneven enhancement, unclear boundaries, spinal cord compression deformation

D: SPECT showing visible abnormal tracer concentration areas at T9 – 10 level

Laboratory examination:

Blood uric acid 754 μmol / L (normal, 140 - 414 μmol / L), white blood cell count 10.4 × 109 / L (normal, (4.0 ~ 10.0) × 109 / L), no abnormalities in results of red blood cell count, red blood cell sedimentation rate, blood urea nitrogen, serum creatinine, HLA-B27, rheumatoid factor, urinary protein, tuberculin test, and tumor markers.

Treatment:

Posterior thoracic spinal canal exploration and decompression surgery under general anesthesia

Resect all the spinal lamina at T9 level and 1/3 of the spinal lamina at T10 level. Epidural lesions, extending through the intervertebral foramens at T9 – 10 level, size of 3 cm x 2 cm x 2 cm, white, granular, smooth boundaries, are seen under the microscope (Figure 2A, Figure 2B). After the resection, the local thecal sac is bulging, and compression on the thoracic vertebral canal is resolved.

Postoperative diagnosis:

Granular sediments, mixed with a large number of foreign body giant cells, are consistent with the diagnosis of tophus (Figure 2C, Figure 2D). 2 weeks after surgery, the lower limbs muscle strength recovered to grade Ⅳ, and the blood uric acid is 740μmol / L; 4 weeks after surgery, the patient discharged. It is recommended for the patient to continue treating from metabolic specialists. 24 months after surgery, lower limbs function recovery is very good, and there is no recurrence.

Figure 2 results of pathological examination.

A: intraoperative exploration, the white arrow pointing to the tophus

B: Intraoperative excisions

C, D: postoperative pathological examination showing granular sediments, mixed with foreign body giant cells.

C: HE x 100, D: HE x 400