Chronic Tophaceous Gout Presenting as Bilateral Knee Masses in an Adult Patient: A Case Report

Gout is a common disorder of uric acid metabolism that leads to the precipitation of monosodium urate crystals. It most commonly affects the first metatarsophalangeal joint but can also affect other joints such as knees, elbows, wrists, and ankles. Chronic gout can present as recurrent episodes of monoarticular or polyarticular inflammatory arthritis, tophaceous soft tissue deposits of monosodium urate crystals, uric acid renal calculi, and/or chronic nephropathy.

We report the case of a 67-year-old Caucasian male patient with bilateral tophaceous gout to his knees involving the soft tissue and ulcerating skin breakdown to his left knee after an acute traumatic injury. Plain radiographs of the bilateral knees revealed large soft tissue masses anterior to the patella. Magnetic resonance imaging of the left knee was also performed which demonstrated heterogeneous masses consistent with tophi and peripheral enhancement with central necrosis. A diagnostic biopsy was performed to rule out malignancy the results confirmed gouty tophi. We report this case to note the atypical presentation of this disease.

Chronic tophaceous gout presenting with ulcerating skin breakdown overlying a fungating tophaceous mass is uncommon considering the current availability of effective pharmaceutical treatments for hyperuricemia. Surgical intervention for tophaceous gout is seldom required and is traditionally reserved for atypical cases that present with deformities, severe pain, and joint destruction. Although ulcerative tophi are rare, they can have significant morbidity and greatly impact patients' quality of life. Surgical intervention was indicated in our patient to excise the mass and avoid infective complications.