A case of brown tumor mimicking fibrous dysplasia in a patient with chronic renal failure Kronik böbrek yetersizliği olan bir hastada fibröz displaziye benzeyen kahverengi (brown) tümör

Renal osteodistrofi, bobrek yetersizligi nedeniyle uzun sure diyalize giren hastalarda ve transplantasyon sonrasinda morbiditenin en onemli nedenlerinden biridir. Klinik ola- rak yuksek dongulu kemik hastaligi, dusuk dongulu kemik hastaligi, osteomalazi, osteoskleroz ve osteoporoz gorule- bilir. Renal yetersizlik nedeniyle diyaliz tedavisi gormekte olan 13 yasinda bir erkek cocugu, hafif travma sonrasi ge - lisen patolojik sol suprakondiler femur kirigi ile basvurdu. Radyolojik incelemelerde suprakondiler femurda, sol aseta- bulum tavani ve sag tibia proksimal ve distal bolgelerinde kistik kitleler goruldu. Lezyonlarin radyolojik goruntuleri ve sag tibia distalinden cikarilan lezyonun histopatolojik ozellikleri goz onune alinarak, ayirici tanida kahverengi (brown) tumor ve fibroz displazi dusunuldu. Hastanin ilk serum paratiroid hormon duzeyi hafif yuksek, kalsiyum du - zeyi normaldi. Takiplerinde serum paratiroid hormon duze- yi belirgin yukselme gosterdi. Boylece, hastaya kahverengi tumor tanisi kondu. Renal osteodystrophy is one of the major causes of mor- bidity in patients receiving long-term dialysis treatment for renal failure and after transplantation. Its clinical impli- cations include high-turnover bone disease, low-turnover bone disease, osteomalacia, osteosclerosis, and osteoporo- sis. A 13-year-old boy who had been on dialysis treatment for renal failure was admitted with a pathologic supracon- dylar femur fracture after a minor trauma. Radiological studies showed cystic lesions in the femoral supracondyle, left acetabular roof, and right proximal and distal tibia. Based on radiologic appearances of the lesions and on his- topathologic findings of the lesion excised from the right distal tibia, brown tumor and fibrous dysplasia were con - sidered in the differential diagnosis. Initially, serum para- thyroid hormone level was slightly increased and calcium level was normal, but during follow-up, serum parathyroid hormone level increased significantly, enabling the diag - nosis of brown tumor.