A 36-year-old woman was referred for the management of generalized tonic–clonic seizure. On admission, episodes of convulsions occurred that shortly turned into status epilepticus, requiring immediate resuscitation and initiation of mechanical ventilation. Although imaging studies of the brain were unremarkable, serum biochemical analyses disclosed high blood urea nitrogen 55.71 mmol/l (normal range 2.5–8.0 mmol/l) and creatinine 689.52 μmol/l (normal range 50–110 μmol/l). Nevertheless, she barely responded to intravenous infusion of sodium valproate, lorazepam and phenytoin. Considering the neurological presentations of uremia, hemodialysis was started promptly. After the first two sessions, the epileptic seizures resolved completely. Further workup incriminated a giant retroperitoneal cystic lymphangioma responsible for the post-renal component of uremia (Fig. 1). A complete tumor resection achieved rapid resolution of obstructive uropathy. The patient was event-free at a 2-year follow-up.

Fig. 1
figure 1

A coronal reformatted image of contrast-enhanced CT scan showing a large fluid-containing tumor with cystic components occupying the entire abdomen with compression of surrounding structures

Full size image

Retroperitoneal cystic lymphangiomas is a rare benign tumor of the lymphatic system, characterized by proliferating lymphatic vessels, slowly growing cysts, and filling with chylous or serous material. It usually presents a diagnostic dilemma, as various types of cystic tumors share similar clinical manifestations. Occasionally, the cystic expansion is large enough to impose on surrounding structures, causing critical compression or obstruction of adjacent retroperitoneal organs. Generally, a total excision is the preferred treatment.