THE PERINEPHRIC SPACE AND RENAL FASCIA - REVIEW OF NORMAL ANATOMY, PATHOLOGY, AND PATHWAYS OF DISEASE SPREAD

The perinephric space is a cone-shaped retroperitoneal compartment con taining the kidney, adrenal gland, perinephric fat, fibrous bridging s epta, and a rich network of perirenal vessel and lymphatics. Perinephr ic space pathology may originate from within or outside the confines o f the perirenal fascia. Most intrinsic perinephric space disease arise s from the kidney or adrenal gland, and secondarily involves the perin ephric space. Disease originating outside the cone of renal fascia may spread to the perinephric space via lymphatics (i.e., metastatic spre ad) or by directly transgressing perirenal fascial planes (e.g., invas ive tumor or infections). Additionally, infiltrating soft tissue or ra pidly accumulating retroperitoneal fluid may travel into or out of the perinephric space via perinephric bridging septa and renal fascia. In this article, we review the normal anatomy of the perinephric space a nd renal fascia, emphasizing the significance of retroperitoneal inter fascial planes and perinephric bridging septa as a potential conduit f or retroperitoneal disease spread. This review of normal anatomy and p athways of disease spread serves as background for a discussion of a v ariety of specific pathologic conditions that may involve the perineph ric space and retroperitoneal fascia, including pancreatitis, retroper itoneal hematoma, urinoma, metastatic disease, and perirenal varices.