The retroperitoneum is an abdominal landmark confined by the posterior parietal peritoneum and the posterior abdominal wall. The main compartments of the retroperitoneum are the perirenal (perinephric) space, the anterior pararenal space, the posterior pararenal space and the great vessel compartment. The spaces are divided by the anterior renal fascia (Gerota), posterior renal fascia (Zuckerkandl) and lateral conal fascia. The retroperitoneal space in the abdomen is continuous with the extraperitoneal space in the pelvis, thereby providing a route for the extension of pathological processes [1-3].

Fig 1: Retroperitoneum anatomy illustration. Illustration by Miruna Mecea, inspired by William E. Brant, Clyde A. Helms. Fundamentals of Diagnostic Radiology 4th Edition; 2012, with anatomical references from Netter FH. Netter’s Atlas of Human Anatomy. 5th ed. Philadelphia: Elsevier; 2018.

Table 1: Retroperitoneum anatomy table. Table created based on [1-4].

Certain studies on the multilaminate nature of the perirenal fascia describe potential planes through the layers of the fascias, including the retromesenteric, retrorenal, lateral conal and combined fascial planes [4]. For the sake of consistency, the cases presented in this poster will be described in accordance with the conventional classification of the retroperitoneal spaces.