Perirenal fibrosis: make your diagnosis

A 72-year-old patient treated with BCG immunotherapy for relapse of urothelial cancer was admitted for diffuse oedema. His past history was characterized by recurrent pleuropericarditis treated by pericardotomy 16 years earlier and by retroperitoneal fibrosis (RPF) treated by steroids 15 years earlier. Serum creatinine rose progressively from 190 to 618 μmol/L and he was admitted in the nephrology department. Clinical examination showed diffuse oedema, dyspnoea and mild tibial tenderness. Haemoglobin was 99 g/L with normal platelet and leukocyte counts. Calcaemia, phosphoraemia, magnesaemia, haptoglobin and lactate deshydrogenase levels were within the normal range. Serum was negative for antinuclear and antineutrophil cytoplasm antibodies. Bilateral pyelic dilatation was diagnosed and treated by bilateral ureteral stenting. Echocardiography, cardiac magnetic resonance imaging (MRI) and right cardiac catheterization confirmed restrictive cardiopathy related to constrictive pericarditis with severe thickening of the lateral wall of the pericardium (not shown). An abdominal CT scan was performed and is shown in Figure 1.