Tophaceous Gout of the Ankle Presenting as a Soft Tissue Mass: A Case Report of an Uncommon Presentation of a Common Disease
2 Zonguldak Karaelmas Üniversitesi Tıp Fakültesi Patoloji Anabilim Dalı, Zonguldak, Türkiye
3 Zonguldak Karaelmas Üniversitesi, Tıp Fakültesi Patoloji Anabilim Dalı, Zonguldak
4 Hacettepe Üniversitesi Tıp Fakültesi Patoloji Anabilim Dalı, Ankara
Gout is a metabolic disorder in which there is either an increase in production or a decrease in excretion of uric acid leading to hyperuricemia. Hyperuricemia results in the deposition of monosodium urate crystals in joints and visceral organs and continued deposition eventually results in chronic tophaceous gout. We report a case of gouty tophi in a 45-year-old man who developed nodules on both lateral aspects of the malleoli with a history of arthropathy. In laboratory investigation, blood chemistry showed marked hyperuricemia (8.40 mg/dl). Macroscopically, the lesions were circumscribed whitish-gray masses. Histologically, both lesions contained areas of amorphous brown crystal deposits and they were surrounded by a foreign body type granulomatous infiltrate. The crystals revealed specific birefringence, a diagnostic characteristic of the monosodium urate crystals, with a polarizing filter. Gout deposits in skin (tophi) are uncommon. The aim of this report is to emphasize the importance of considering this disease entity in the differential diagnosis of a soft tissue lesion in a patient with chronic arthritis.
Keywords : Gout, tophi, urate crystals