E2093. The Renal Sinus: A Small Space with a Large Differential
  1. Jeffrey Guccione; University of Texas Health Sciences Center at Houston
  2. Christine Menias; Mayo Clinic
  3. Ayman Gaballah; University of Missouri
  4. Dhakshinamoorthy Ganeshan; MD Anderson Cancer Center
  5. Khaled Elsayes; MD Anderson Cancer Center
The renal sinus is a relatively large space at the medial border of the kidney. Although frequently overlooked, it can be involved in a wide range of neoplastic and non-neoplastic processes. The anatomical make up and landmarks are important for understanding these diseases. Particularly since the various contents of the renal sinus are small in number and knowing these, in addition to the adjacent structures, allows for the formulation of a thorough differential diagnosis. Various imaging modalities can be used to evaluate the renal sinus, although each has its own benefits, and specific protocols can be used to maximize diagnosis based on the differential.

Educational Goals / Teaching Points
The anatomical make up and landmarks of the renal sinus are important for understanding pathology. A thorough differential diagnosis can be developed based upon the renal sinus contents and adjacent structures. To maximize diagnosis, optimal imaging protocols and techniques should be included based on this differential. Diagnosis can often be made based on recognition of imaging features and understanding the differential possibilities.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The renal sinus is at the deep medial recess of the kidney and is an extension of the perinephric space. Disease processes can arise directly from within or extend into this space. Therefore, as a result of being more common, renal lesions are the most frequent abnormalities found disrupting the renal sinus. However, many other abnormalities can present with sinus involvement, with intrinsic disease arising from one of the various constituents. Fat is the most abundant component, although there are several others from which disease can arise. Knowing these helps in formulating differential and selecting appropriate follow-up imaging and protocols for complete evaluation. Then, based on disease specific imaging findings, the differential can usually be narrowed, and an accurate diagnosis made.

The renal sinus is frequently overlooked but often involved in numerous disease processes, both intrinsic and extrinsic. By knowing the anatomical boundaries and constituents, the primary abnormality can be identified, and a differential diagnosis formulated. This differential can then frequently be narrowed, and a diagnosis made, based on specific imaging features.