Vascular Extension from an Infiltrating Renal Tumor
61-year-old male patient presented with chief complaintsof recurrent right renal colic and hematuria.
A 'stone protocol' non contrast CT scan of the abdomenand pelvis was performed, which revealed hyperdense bloodin the pelvicalyceal system (Image. A) and blood clots in thebladder (not shown). A contrast enhanced CT scan of theabdomen and pelvis (Image B) revealed an infiltrative lesioninvolving the pelvicalyceal system of the right kidney withthrombosis of the right renal vein. Coronal T1 weighted post contrast MRI (Image C) revealed an infiltrative massinvolving the right kidney with notable absence of caliectasis or hydronephrosis. Thrombus involving the right renal veinand the inferior vena cava was seen as a filling defect. Themicroscopic examination of the surgical specimen revealedclear cell type renal cell cancer, with tumor extending intothe right renal vein and its walls. On surgical exploration,tumor invasion of the renal capsule with extension into theperinephric fat but restricted to Gerota's fascia was seen.
Neoplasms account for a significant number ofinfiltrative renal lesions seen on imaging studies and include a variety of uncommon tumors such as renal medullary carcinoma. However, infiltrative growth is an atypical manifestation (6% of cases) of commonly encountered renal cell carcinoma . The more common subtypes of renal cell cancer -clear cell, papillary, and chromophobe cell-typically appear as well-defined mass and may form a capsule of connective tissue and compressed atrophic renal parenchyma with tumor proliferation. Occasionally, the tumor appears ill-defined and infiltrative; this appearance is more typical of the uncommon sarcomatoid subtype but may be seen with the other subtypes as well. Absence of caliectasis is usually a clue to the diagnosis of renal cell cancer over transitional cell cancer. However renal vein invasion can occur in both types of carcinoma.
Conflict of Interest
The author confirms that this article content has no conflict of interest.
 Pickhardt PJ, Lonergan GJ, Davis CJ Jr, Kashitani N, Wagner BJ. From the archives of the AFIP. Infiltrative renal lesions: radiologicpathologic correlation. Radiographics 2000; 20(1): 215-43.
* Address correspondence to this author at the Radiology Department, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX -75216, USA; Tel: 214 857 0185; Fax: 214 857 0173; E-mail: [email protected]
This material is adapated with permission from The Open Urology & Nephrology Journal