Renal Cell Carcinoma

Understanding the pathological characteristics of Renal Cell Carcinoma is essential to plan the imaging strategy

In can be bilateral in 5% of patients
Associated with von-Hippel-Lindau disease, Tuberosclerosis and Polycystic disease
Presents as mass lesions 3-15 cm in diameter
As they grow they distort renal outline and grow into renal pelvis and fungate through the walls of the collecting system into surrounding tissue
Tumor is highly vascular
Tumor becomes necrotic and cystic areas can be seen.
There is a tendency to invade renal vein and extend to inferior vena cava and heart.
There is a tendency to metastasize widely to lungs, bones and lymph nodes, liver, adrenals and brain and opposite kidney

Objective for imaging procedures

CT abdomen and pelvis with contrast is the procedure of choice when a renal neoplasm is suspected to evaluate the mass and stage the tumor.

Can delineates cysts from solids.
- Case with hypo dense Mass
- Case showing a mass with cystic and solid components
Can show tumor enhancement.
- Case showing heterogenous enhancing mass
- Case showing inhomogeneous contrast enhancement Image Image
May show calcifications
Can show involvement of renal vein
Can show involvement of peri-nephric fat
Can assist with fine needle aspiration biopsy
Can show metastases to liver, nodes and bones
- Case showing nodal metastasis
Better in showing tumor recurrence
- Case showing tumor recurrence

Chest x-ray is a routine initial procedure looking for metastasis. CT chest is superior in detecting occult metastatic lesions.

Role of other imaging procedures:

MRI: with contrast is a good alternative when iodinated contrast cannot be used because of renal failure or when vascular patency and involvement needs to be assessed.
Ultrasound: is a simple screening procedure to distinguish a cystic from a solid mass. Vascular status can also be assessed with Doppler.
- Most masses are hyper echoic; some may be hypo echoic and some may be isoechoic to the parenchyma
- Necrotic mass; may be seen as cystic with thick walls
- IVC involvement with thrombus may be seen
IVP and renal angiograms (Neovascularization Image ) are rarely done nowadays. MRI and CT provide all the necessary information about the status of renal vaculature and inferior vena cava.