[Pararenal pseudocyst. A rare sequela following blunt abdominal trauma (author's transl)]

On the basis of an organ preserving operative case, the patho-physiological postulation of the origin and the diagnostic difficulty of this rare clinical picture are discussed. Out of the only 30 cases known in the world literature, 26 nephrectomies had to be made. Decisive for the formation are the grave concomitant injuries which mask the local symptomatology of the ureter tear. The duration of the interval trauma - therapy influences decisively the chances of organ preservation (from many weeks to 37 years is unknown).