Erdheim-Chester disease: case report and review of associated urological, radiological and histological features.

A 48-year-old man presented with progressive gait ataxia, slurring of speech and bilateral leg weakness 6 months in duration. Neurological evaluation included computerized tomography (CT) of the head, magnetic resonance imaging and myelography, all of which were negative for neuromuscular deficiency. Positron emission tomography showed increased uptake in the radii and femora bilaterally. Presumptive diagnosis was Paget’s disease, and the symptoms stabilized for several months. However, the patient subsequently presented with bilateral flank pain and an increased serum creatinine of 4.5 g./ml. (normal 0.6 to 1.2 mg./dl.). CT of the abdomen demonstrated bilateral hydronephrosis and perinephric fat infiltration (fig. 1, A). Indwelling ureteral stents were placed and a diagnosis of Erdheim-Chester disease was considered. Plain x-rays of the extremities revealed cortical and medullary sclerosis of the distal radii and femora-findings classic for Erdheim-Chester disease (fig. 1, B). Laparoscopic retroperitoneal biopsy of the perinephric tissue showed nonLangerhans type histiocytosis (fig. 2). The patient is currently being treated with oral 6-mercaptopurine. He continues to require an indwelling ureteral stent.