To identify and describe the various imaging features of pathologic processes involving the renal sinus.

The renal sinus is a central spacious cavity located at the medial aspect of the kidney that communicates with the perinephric space. The renal sinus is surrounded by the kidney parenchyma laterally. It is mainly occupied by adipose tissue and contains themajor branches of the renal artery and vein along with the major and minor calices of the collecting system, lymphatic channels, nerve fibers of the autonomic nervous system, and varying quantities of fibrous tissue. [1-3] Therefore, a broad spectrum of pathologic lesions can occur...

Tumors of the renal sinus Various types of benign and malignant lesions can be found involving the renal sinus. Observation of renal sinus fat is important in detecting a small tumor and determining the tumor stage. Malignant tumors arising from the renal pelvis constitute only 5% of urinary tract neoplasms. [5] Transitional cell carcinomas (TCC) account for 95% of all uroepithelial tumours of the renal pelvis (the remaining 5% being made up of squamous cell carcinoma (SCC) (the majority) and adenocarcinoma (rare). TCC have one...

A broad pathologic spectrum of conditions can occur in the renal sinus. Familiarity with the imaging features and differential diagnoses of different renal sinus pathology will facilitate prompt, accurate diagnosis and treatment.

1.Rha SE et al: Therenal sinus:pathologic spectrum and multimodality imaging approach. Radiographics.1:117-31. Review, 2004. 2. Tamboli P et al: Benign tumors and tumor-like lesions of the adult kidney. II. Benign mesenchymal and mixed neoplasms, and tumor-like lesions. Adv Anat Pathol 2000;7(1):47–66. 3. Amis ES Jr. Cysts of the renal sinus. In: Pollack HM, McClennan BL, eds. Clinical urography. 2nd ed. Philadelphia, Pa: Saunders, 2000; 1404– 1412. 4. Jeffrey RB Jr. Clinical impact of multidetector CT. In: Fishman EK, Jeffrey RB Jr, eds. Multidetector CT: principles,...