Erdheim-Chester disease (ECD) is a rare histiocytic disorder; the incidence is unknown.The clinical course varies from an asymptomatic state to a fatal disease; kidneys and retroperitoneum are frequently involved but renal impairment, caused by both renal sinus and parenchyma direct invasion or ureteral obstruction, is rare.
A 60-year-old female, suffering from diabetes mellitus treated with metformin, was admitted for fever, abdominal pain, diarrhoea, acute renal failure (ARF). For 2 years she was suffering from ECD. She had performed interferon therapy with stability of her clinical status. Since the diagnosis she had bilateral hydronephrosis, but she had never suffered from impaired renal function. At admission, laboratory examinations showed: creatinine: 19 mg/dl, leukocytes 21.500/mmc, PLT: 54.000/mmc, Hb: 11 gr/dl, pH: 7.05, HCO3-: 9, serum lactates: 6 mEq/L. Other routine laboratory examinations were in the normal range. Renal ultrasound showed a bilateral hydronephrosis, more to right side.
A percutaneous nephrostomy was placed to right side; the patient received antibiotic and saline solution therapy with a progressive improvement of clinical status (remission of fever, recovery of diuresis, normalization of renal function and acid-base balance); blood and urine cultures were negative for bacterial growth. At the complete normalization of renal function (Creatinine: 1.16 mg/dl), we performed a CT scan with contrast which showed a slight hydronephrosis on the right (Fig. 1) and a marked hydronephrosis on the left side (Fig. 2).
We diagnosed an intestinal discomfort and lactic acidosis metformin associated with ARF secondary to dehydration. We remove percutaneous nephrostomy. In view of the extreme variability of prognosis and the therapeutic prescription decided upon on a case-by-case basis, we adopted a wait-and-see policy in the outpatient clinic. We counseled an ureteral stenting if deterioration both hydronephrosis or renal function.
