Renal angiomyolipoma is a benign tumor that forms in the kidney. This lump is made up of blood vessels, immature smooth muscle fibers, and fat cells. Though anyone can get angiomyolipoma, it is more common in women over 50. A person can have multiple tumors, and these can develop in both kidneys. Here are the angiomyolipoma types, their symptoms, causes, and treatment options one should be aware of.

Types of angiomyolipoma

Angiomyolipoma is of three different types based on the tumor’s tissue type.

• Classic angiomyolipoma: In this variant, the tumor is composed of thick blood vessels, smooth muscles, and adipose tissue. Classic angiomyolipoma usually does not grow. Rarely, if they do enlarge, it is very slow. However, during pregnancy, these tumors may grow rapidly.
• Monophasic angiomyolipoma: This variant has tumors of a single component, either adipose tissue or smooth muscles.
• Epithelioid angiomyolipoma: This is a rare variant of angiomyolipoma where the tumors mostly comprise epithelioid cells. These line the kidney’s blood vessels. This variant has the potential to become cancerous.

Symptoms
Most people with renal angiomyolipoma do not exhibit any warning signs. If the tumor becomes large or if the blood vessels in it rupture, the condition can cause the following symptoms:

• Anemia: Large tumors can cause excessive bleeding, decreasing the production of healthy red blood cells, which makes the person anemic.
• High blood pressure: The tumor compresses the renal artery, and this leads to an increase in blood pressure.
• Discomfort or pain in the abdomen, back, and sides: The tumor can cause pain or discomfort in the abdomen, back, and sides. This is due to the bleeding around the kidney.
• Blood in the urine: A symptom of angiomyolipoma is the appearance of blood or blood cells in the urine, a condition called hematuria.
• Lump: Large tumors may be felt by touch.
• Nausea and vomiting: Nausea and vomiting in people with large angiomyolipoma or when the tumor ruptures
• Shock: People often experience shock due to severe hemorrhage from rupture. Some signs of it include confusion, dizziness, rapid heart rate, pale skin, and abnormal breathing.

The tumor is usually diagnosed when a person undergoes tests for another medical condition. In rare cases, it is discovered when a spontaneous and potentially life-threatening hemorrhage occurs.

Causes
Changes in certain genes can play a role in developing angiomyolipoma. When the tumor suppressor genes TSC1 or TSC2 mutate, it can affect tuberin production, which is a protein that helps control the growth and size of the cell. This results in rapid cell division and the formation of tumors. Renal angiomyolipoma is often related to conditions such as the ones mentioned below:

• Lymphangioleiomyomatosis: This lung disease results from changes in the TSC1 and TSC2 genes. Patients with this condition can also develop growths in the kidneys, leading to angiomyolipoma.
• Neurofibromatosis type 1: It is also called Von Recklinghausen disease; this is caused by an abnormal increase in cell growth, resulting in the formation of tumors all over the body, including kidneys.
• Tuberous sclerosis complex: This genetic disease causes noncancerous tumors to grow throughout the body. The renal angiomyolipoma associated with this disorder tends to be more aggressive and is likely to be large and bilateral.
• von Hippel-Lindau disease: This genetic disorder is also associated with the development of tumors in the brain, spinal cord, eyes, kidneys, pancreas, and adrenal glands. People with this condition have a higher risk of getting angiomyolipoma.

Treatment
If the tumor is small and does not cause any symptoms, the healthcare provider might decide not to give the patient immediate treatment. Instead, regular tests will be conducted to monitor any changes.

The healthcare provider may recommend treatment to prevent possible bleeding. Therapies for renal angiomyolipoma are aimed at either stopping the tumor’s growth or removing it. Surgery may be recommended in cases when there are symptoms, the mass is four centimeters or larger, the tumor is cancerous, those who are planning to conceive, and if there is limited access to emergency services in case of hemorrhage.

Some of the surgical methods to remove renal angiomyolipoma are as follows:

• Embolization: An incision is made in the inner thigh, and a catheter is used to insert tiny beads in the blood vessel serving the tumor. This blocks the blood flow causing the angiomyolipoma to shrink and minimize the risk of bleeding.
• Nephrectomy: In this procedure, the entire kidney containing the angiomyolipoma is removed. This surgical method is only done when the tumor is quite large.
• Radiofrequency ablation: The therapy uses radiofrequency waves to destroy angiomyolipoma.
• Nephron-sparing surgery or partial nephrectomy: A portion of the kidney that contains angiomyolipoma is removed in partial nephrectomy.

There is no way to prevent angiomyolipoma, as the tumor develops spontaneously. People who have certain medical conditions should get imaging tests done regularly to catch any tumor growth early and prevent bleeding, which can be life-threatening.