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The kidneys are two reddish-brown, bean-shaped organs located just above the waist. One kidney is just to the left, and the other just to the right of the backbone. Both are partially protected by the lower ribcage.
The kidney's main function is to filter the blood and rid the body of excess water, salt, and waste products. The filtered waste products are concentrated into urine. Urine leaves the kidneys through long slender tubes called ureters that connect to the bladder. Urine flows down the ureters into the bladder, where it is stored until urination. |
Cancer is a group of many different diseases that have some important things in common. Cancer affects cells, the body's basic unit of life. To understand different types of cancer, such as bladder cancer, it is helpful to know about normal cells and what happens when they become cancerous.
The body is made up of many types of cells. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process helps keep the body healthy. Sometimes cells keep dividing when new cells are not needed. These cells form a mass of extra tissue, called a growth or tumor. Tumors can be benign or malignant.
- Benign tumors are not cancer. They often can be removed and in most cases, they do not come back. Cells in benign tumors do not spread to other parts of the body. Most important, benign tumors are rarely a threat to life.
- Malignant tumors are cancer. Cells in malignant tumors are abnormal and divide without control or order. These cancer cells can invade and destroy the tissues around them. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system. This process is the way cancer spreads from the original (primary) tumor to form new tumors in other parts of the body.
Several types of cancer can develop in the kidney. Renal cell cancer is the most common type of kidney cancer, and occurs more often in men than in women. Renal is the Latin word for kidney.
Like all cancers, renal cell cancer begins small and grows larger over time. Although renal cell cancer usually grows as a single mass within the kidney, a kidney may contain more than one tumor, or tumors may be found in both kidneys at the same time. Some renal cell cancers are noticed only after they have become quite large, but most are found before they metastasize (spread) to other organs through the bloodstream or lymph vessels.
Transitional cell cancer, which affects the lining of the renal pelvis, is a less common form of kidney cancer. It is similar to cancer that occurs in the lining of the bladder and is often treated like bladder cancer.
Stage I:
Cancer is in the kidney only and the size of the tumor is less than or equal to 7.0 cm in diameter. The estimated five-year survival of patients with this stage is over 90 percent.
Stage II:
Cancer is in the kidney only and the size of the tumor is greater than 7.0 cm in diameter. The estimated five-year survival of patients with this stage is over 75 percent.
Stage III:
The tumor in the kidney may be any size and has extended beyond the kidney capsule but not beyond the Gerota's fascia (layer of tissue that encapsulates the kidney and surround fat and adrenal gland). Additionally, cancer may have spread to the main blood vessel that carries blood away from the kidney (the renal vein), to the blood vessel that carries blood from the lower part of the body to the heart (inferior vena cava), or to the adjacent adrenal gland. The estimated five-year survival of patients with this stage is about 50 percent, depending on involved sites.
Stage IV:
Tumor in the kidney extends beyond Gerota's fascia and/or cancer has spread to more than one lymph node near the kidney. Evidence that cancer has spread to other organs in the body, such as the lungs, liver, brain, bones, intestines or pancreas, also indicates Stage IV disease. The estimated five-year survival of patients with this stage is less than 10 percent.
Due to the deep location of the kidneys, there may not be any symptoms until the tumor has grown quite large. The most common symptom is blood in the urine (hematuria). Other symptoms of kidney cancer may include:
- A lump or mass in the kidney area
- Recurrent fever
- Rapid weight loss
- Lingering dull ache or pain in the side, abdomen or lower back
- Feeling fatigued or in poor health
Small and early stage renal cell carcinomas are commonly diagnosed incidentally by routine ultrasound and CT scans done for other unrelated symptoms and health problems. Larger renal cell carcinomas usually present with symptoms. There are several tests used to detect and stage kidney cancer:
- Imaging studies #
These are ultrasound, intravenous pyelogram (IVP), CT scan and MRI scan. CT of the kidneys involve injecting a dye into the blood streams during the scanning. Kidney cancer will enhance (or light up brilliantly) while other pathology like renal cyst will not enhance. This is the best imaging modality. These CT scan is used to stage the disease as well. In patients with poorly functioning kidney or has allergies to contrast (dye), MRI is done instead.
- Fine Needle Aspiration (FNA) #
This is seldom done as modern imaging is very accurate in predicting the malignant nature of kidney tumours. Only in very unusual occasion where accurate diagnosis is in doubt that a FNA is done.
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