A 17-year-old man experienced night pain in his right hallux. Radiographs revealed a lytic lesion in the proximal phalanx of the right hallux. Magnetic resonance imaging showed a low-signal intensity mass on T1-weighted sequences and isointense-high-signal intensity on T2-weighted sequences. We suspected a benign bone tumor such as osteoid osteoma or a bone cyst and consequently performed biopsy and surgical treatment. The lesion was filled with a whitish chalk-like substance, and pathologic examination revealed tophaceous gout.
It can be difficult to distinguish intraosseous tophaceous gout from other diseases, including bone tumors, using imaging; hence, pathological examination may be necessary for the diagnosis.