Giant hydronephrosis of about one-quarter of the body weight

We report on a giant hydronephrosis with a contents of ca. 19 liters that had developed at the site of a ureteropelvic junction obstruction. Therapy consisted of percutaneous nephrostomy and reduction of the hydronephrosis by successive drainage over 18 days, followed by nephrectomy. Diagnostic workup and possible pitfalls of the differential diagnosis are addressed. Even without prior trauma, hydronephrosis should be considered as one of the possible causes of massive abdominal swelling.