Retroperitoneal fibrosis of unknown origin.

the renal pelvis and calyces obtaining special views, could sider the possibility of Erdheim–Chester disease. Another distinctive feature is prominent extension of the fibrotic visualize the stent as an echogenic double-line structure in the renal calyx (Figure 1C) which could have been easily process within the renal pelvis and throughout the renal capsula, while mid-line structures including aorta, inferior mistaken for a calcified vessel. vena cava and common iliac vessels are spared. Of note, the Comment. With the widespread use of ultrasonography, lateral margins of the infiltration are poorly defined by practising nephrologists must be aware of the fact that CT-scan or MRI. A smoldering but unremitting course is ultrasound could miss ureteral stents if not looked for observed in most patients. Follow-up may extend over dec-diligently. Plain radiograph remains the best method to ades. No specific treatment is yet available, and most patients visualize the ureteral stent, whenever their presence or posi-are treated conservatively. tion is in question. In conclusion, in the patient reported by Rajemiarimoelisoa et al. we propose to extend investigations Division of Nephrology G. Pandurangan towards (i) checking for cutaneous or eyelid deposits, (ii) per-St Louis University School of Medicine B. Bastani forming X-ray of long bones, (iii) reviewing pathological St Louis tissue obtained at pericardotomy for xanthomatous infiltra-MO tion and (iv) performing cerebral and thoracic magnetic USA resonance imaging. This may allow the definitive assessment 1. McKiernan JM, Katz AE, Goluboff ET. A long-forgotten ureteral of our Erdheim–Chester hypothesis. Paris Double-J ureteral stents for temporary and permanent urinary France drainage: experience with 87 patients. Chester–Erdheim disease: a neoplastic disorder. 'Images in Nephrology' an intriguing case of retroperitoneal fibrosis of unknown origin [1]. The image provided and the pathological description reminded us of similar cases with The short evaluation of the injured patients with acute Erdheim–Chester disease, and we would like to submit this renal failure who required dialysis and transferred to our possibility to the authors. The findings of perirenal and renal centre during the Marmara earthquake infiltration, combined with major bilateral pyelocaliceal dilatation, and fibrous tissue including histiocytes suggest considering this rare condition. Sir, On 17 August 1999, an earthquake struck a densely populated Although Erdheim–Chester disease may initially present as a localized process, it is a systemic condition. Apart from region in northwestern Turkey. Four major cities and a number of towns and villages were destroyed. Approximately retroperitoneal infiltration, other suggestive findings include …