Ca Renal (ENARM)

The renal system is composed of 2 kidneys, 2 ureters, a bladder, and a urethra. These structures function to filter blood and excrete urine, which contains waste products of metabolism. Varying conditions such as infections, cysts, solid masses, ischemia, and mechanical obstruction can affect the renal system. Evaluation of diseases rely on imaging methods such as radiography, ultrasonography, CT, and MRI. Some of these are also used to guide tissue sampling (e.g., renal biopsy).

The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spine. As part of the urinary tract, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine. The kidneys also play a major role in homeostatic processes, including electrolyte concentration, blood pressure, and acid–base regulation. Grossly, they consist of an outer cortex and inner medulla. Microscopic functional units known as nephrons filter the blood through a structure called the glomerulus, and this filtrate is then modified and concentrated as it moves through a complex tubular system. The renal arteries supply the kidneys via a central opening, known as the renal hilum, on its medial side; large renal veins empty directly into the vena cava.

Renal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%–85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. The disease usually presents asymptomatically. When symptoms finally arise, the tumor has already grown significantly and/or spread to other tissues. The classic clinical triad of RCC is flank pain, hematuria, and a palpable abdominal renal mass, but this triad appears in only about 9% of cases. Affected individuals also commonly present with fever and/or anemia. Renal cell carcinoma is usually diagnosed via CT scan of the abdomen and pelvis. Localized cases of RCC are commonly treated and cured with surgery, and advanced cases are treated with a combination of immunotherapy and/or molecular targeted therapy. The long-term prognosis for locally advanced or metastatic RCC is often poor.