Non-cancerous Tumors of the Kidney

What are Non-cancerous Tumors of the Kidney?

Non-cancerous tumors of the kidney, also known as benign kidney tumors, are the result of abnormal growth of kidney cells that form tumors but do not spread to other parts of the body and are not usually life-threatening. The kidneys are a pair of bean-shaped organs that are part of the excretory system present on both sides of the spine behind the abdomen. Their main function is to filter blood by eliminating waste materials in the form of urine and to maintain the overall volume of body fluids.

Causes and Risk Factors of Non-cancerous Tumors of the Kidney

The specific cause for the development of non-cancerous tumors of the kidney is unclear; however, factors that increase the risk include:

• Smoking
• Genetic defects
• Exposure to radiation and chemicals
• Obesity
• Chronic kidney disease
• Alcohol consumption

Types of Non-cancerous Tumors of the Kidney

Some of the common types of non-cancerous tumors of the kidney include:

• Oncocytoma

These are asymptomatic tumors that are mostly present in the collecting duct of the kidney. They can grow to a large size and may develop throughout the body.

• Fibroma

Also known as medullary fibroma, this is a rare tumor that develops in the fibrous tissue of the kidney. It is more common in women.

• Papillary renal adenoma

This is the most common benign kidney tumor and is small, slow-growing, and usually asymptomatic.

• Angiomyolipoma

These noncancerous kidney tumors are also known as renal hamartomas. They are mainly due to an inherited genetic mutation that also affects the brain, eyes, and skin. These tumors are composed of blood vessels, fat, and smooth muscle. Occasionally they can cause hemorrhage and can be fatal.

• Lipoma 

This tumor develops in the fat cells within the renal capsule. It is most commonly seen in middle-aged women.

Symptoms of Non-cancerous Tumors of the Kidney

Some of the most common symptoms of non-cancerous tumors of the kidney include:

• Anemia 
• Loss of appetite
• Unexplained weight loss
• Tiredness
• Abdominal pain
• Lower back pain
• Swelling in the ankle and legs
• Hematuria (blood in urine)
• Recurrent fever

Diagnosis of Non-cancerous Tumors of the Kidney

Your doctor will review your medical history and symptoms and perform a physical examination. The following diagnostic tests may be ordered:

• Urinalysis: This test helps to determine the presence of blood, infection, and protein in the urine.
• Blood Test: This helps to detect a low red blood cell count in the blood.
• Biopsy: This is an image-guided procedure in which a thin needle is injected into the kidney and a small sample of tissue is taken from the tumor and observed under a microscope.
• Computed Tomography (CT) scan: This scan uses multiple x-rays to produce detailed cross-sectional images of the kidneys and abdomen.
• Ultrasound: This study uses high-frequency sound waves to produce images of the tissues and to detect the presence of any cyst or tumor.
• Magnetic Resonance Imaging (MRI) Scan: This study uses a large magnetic field and radio waves to produce images that help in detecting damage or abnormalities in soft tissues and measuring the size of the tumor.
• Cystoscopy: A long, thin instrument with a tiny lens and light source is inserted into the upper urinary tract or renal pelvis to diagnose a kidney tumor.

Treatment for Non-cancerous Tumors of the Kidney

Treatment for non-cancerous tumors of the kidney varies based on severity, kidney function, and patient age. Some common treatment methods include:

Conservative Methods

• Active Surveillance: In this method, your doctor will not provide treatment directly, but instead will analyze any tumor smaller than 4 cm at regular intervals and follow a “wait and watch” approach.
• Thermal Ablation: This involves the destruction of the tumor cells using heat or cold.
• Chemotherapy: A process whereby medication is given orally or intravenously to destroy the tumor.
• Radiation Therapy: High-energy external beams of radiation are directed into the body to destroy cancer cells.
• Immunotherapy: Also known as biologic therapy, this is a method that boosts your body's natural immunity to destroy the tumor.

If these more conservative methods fail to improve symptoms, the following surgeries may be recommended and are most effective in the early stages of cancer:

• Laparoscopic Nephrectomy: This is a minimally invasive surgical procedure that involves the removal of the kidney affected by the tumor.
• Radical Nephrectomy: This involves the removal of the whole kidney along with the surrounding fatty tissue, lymph nodes, and adrenal glands.
• Partial Nephrectomy: This is a minimally invasive surgical technique that involves the removal of the tumor or a portion of a kidney while the healthy tissue is left intact.