Retroperitoneal fibrosis in Marfan's syndrome.

To our knowledge, an association between Marfan's syndrome and retroperitoneal fibrosis (RPF) has never been described. We describe two cases who presented acutely with aortic disease and were later found to have changes of undiagnosed retroperitoneal fibrosis causing hydronephrosis on computed tomography (CT). An association is readily understandable based on the current hypotheses for the aortic disease in Marfan's syndrome and the etiology of RPF. We suggest why this has not been noted previously. CT has an established role in the diagnosis and follow up of RPF as well as in the assessment of the aortic complications of Marfan's syndrome. Awareness of the possibility of RPF and it's demonstration on CT may allow early diagnosis and help prevent significant renal impairment.