Chronic back pain in untreated gout

A 41-year-old man with a 10-year history of untreated chronic tophaceous gout presented with acute flare of gouty arthritis. He has chronic low back pain which has become more severe for the past 1 year. Clinically he has tenderness at lower lumbar spine although there was no neurological deficit. Laboratory test revealed raised inflammatory markers (ESR 70mm/hour) and C-reactive protein 287.1 mg/L, reactive thrombocytosis and leucocytosis, renal impairment and elevated serum uric acid (780 μmol/L). He had microscopic hematuria and ultrasound showed right mild hydronephrosis without any calculi identified. Computerized Tomography Urogram (CTU) confirmed the findings of an obstructive right hydronephrosis and hydroureter due to a right ureteric calculus. Incidentally, CTU revealed a lobulated, heterogenous hyperdense soft tissue ossified mass measuring (4.6x7.3x8.1 cm) at lumbar vertebral bodies (L2-L4) with overhanging edge erosions of adjacent vertebra mainly involving the facet joints, pedicles and lamina (Figure 1).