Intra-osseous tophaceous gout of a bipartite patella mimicking aggressive bone tumour.

This is a very rare case of gouty tophus in the patella of a 31-year-old male, without any medical co-morbidities. The patient initially presented after an injury to left knee but came back months later due to persistence of pain. Surgical decision was made based on imaging findings in computed tomography and magnetic resonance imaging of an intraosseous lesion that has increased in size. The initial diagnosis is that of an aggressive bone tumour. The diagnosis of an intraosseous gout was made intra-operatively upon seeing the characteristics of the lesion, and upon confirmation of the biopsy results. Gout can usually be managed medically with urate lowering drugs and lifestyle change. However, when presented with a tophus that is increasing in size and causing mass effect on the involved bone, surgical management is indicated.