[Long-term follow-up of peripelvic renal multicystic lymphangiectasia].

Renal peripelvic multicystic lymphangiectasia is a benign disease characterized by multiple cysts arising from the lymphatic vessels of the renal sinus. Cysts, almost always bilateral, surround the profiles of the calices; the biggest cysts can compress pelvis or iuxtapielic ureter and it is difficult to differentiate RPML from hydronephrosis at the Ultrasound. Cysts are asymptomatic, the profiles of calices appear irregular with thin membrane separating each other, the cortical of the kidney is preserved: these are principle elements to distinguish RPML to hydronephrosis at the Ultrasound. Usually it is necessary to confirm the diagnosis at IVP and CT scan evaluation. From 1995 to March 2002, 10 cases of RPML with a long-term follow-up have been studied. IVP in 8 patients and CT scan in 2 have shown compression of the collecting system by multiple cysts. We followed the cases with periodic lab tests of kidney function, ultrasound, IVP, CT scan. In order to valuate the presence of "true obstruction", we tested in over-night urine EGF and MCP-1 as markers of urinary tract obstruction and subsequent renal damage. A valuable data regarding how to differentiate RPML from hydronephrosis at Ultrasound show that RPML does not modify renal function and cyst volume has not changed in the time. In long-term follow-up the prognosis of the RPML is not clear. Particolarly this renal sinus disease has not neoplastic degeneration and the effect of cysts on kidney function is unknown. RPML is an uncommon disease and it can be enclosed in the group of renal sinus pathologies. The absence of symptoms, the hystologic diagnosis, the unchanged dimensions of the cysts confirm the benign prognosis of RPML which does not need a close functional and morphologic monitoring in the long-term follow-up.