[Multilocular cyst of the kidney. Characteristics of the imaging appearance].

Investigations in a patient with a multilocular cyst of kidney included urography, ultrasonography and computed tomography. Urography images showed a mass occupying the lower half of the left kidney with a lacunar image of pelvis, the association of these two elements suggesting a possible cancer of kidney. Ultrasound and computed tomography imaging demonstrated the fluid nature of the mass with absent partitioning. Findings were compared with data from the pathologic specimen which showed a main unilocular cyst with multiple satellite smaller cysts and a thick intrapyelic formation composed of microcystic aggregates. Pre-operative diagnosis of multilocular cyst was assisted by the use of modern imaging techniques: ultrasound and CT scan, which demonstrated a partitioned renal cystic lesion. Diagnosis is still difficult in atypical forms, however, and the relative frequency of an intrapyelic cyst protrusion is emphasized.