Angiomyolipoma is a non cancerous tumor composed of fat cells, blood vessels, and smooth muscles. This tumor can develop in any part of body such as the pancreas or adrenal glands, but it is predominantly seen in kidneys. Renal angiomyolipoma is one of the common tumors of kidney, as at least 1 percent of all renal tumors comprises of aniomyolipoma. This tumor occurs mainly in middle aged individuals with a ration of 4 men for 11 women.
Most angiomyolipoma are sporadic in origin, but small numbers of patients with angiomyolipoma of kidney are associated with a rare genetic disease called tuberous sclerosis complex.Usually the tumor develops only in one kidney. The common sign and symptom include blood in urine, frequent renal infection, pain in abdomen. If the tumor enlarges in its size it can burst and cause profuse bleeding which may be life threatening.
The treatment of choice is complete surgical removal of the mass which may need partial nephrectomy or sometime total removal of kidney with the lesion. Recently certain medicines are also tried as a conservative option. Prognosis of the condition is good after the treatment since the growth is benign.
What Causes Angiomyolipoma Of Kidney?
The exact cause of angiomyolipoma of kidney is not known but it is believed to develop due as a hereditary trait or may be as a sporadic event.It is a benign tumor that is composed of blood vessels, smooth muscles, fat cells. Majority cases of angiomyolipoma of kidney are sporadic in origin and the rest may be associated with tuberous sclerosis complex, a genetic disorder with mutation of genes occurring on TSC1 and TSC2 gene.
The benign growth is usually seen more in females as compared to males because its formation occurs faster in presence of female hormones estrogen and progesterone. The average age of its development is between 35 to 50 years. Besides its association with tuberous sclerosis, some angiomyolipoma of kidney are also associated with other genetic syndromes such as von Hipple Lindua disease and Struge Weber syndrome. Due to the hormonal influence the tumor has tendency to grow larger in size during pregnancy.
Signs And Symptoms Of Renal Angiomyolipoma
Angiomyolipoma of kidney may occur in outer aspect of kidney or the inner area. Signs and symptoms may vary depending on the size of tumor. Sometimes the growth remains asymptomatic if the size is too small. However a growing tumor produces constellation of symptoms.
Usually tumor more than 4 cm will start producing unwanted symptoms. In majority of cases only one kidney is affected. However, if it is associated with tuberous sclerosis, both the kidney has multiple angiomyolipoma.
- Constant pain in flanks and abdomen. Pain may be dull or sharp.
- A palpable swelling in the lumbar area of spine. This is because of the enlargement of growing tumor.
- Red or brown colored urine due to passage of blood in urine.
- Frequent urinary tract infection.
- Raised blood pressure.
- Tumor grows in size during pregnancy.
A large growing tumor can sometime burst resulting in heavy bleeding which may lead to life threatening complications.
Treatment Of Kidney Angiomyolipoma
Angiomyolipoma of kidney are often exceptionally small in size and they are diagnosed only on radiological imaging techniques such as CT scan or sonogram done for some other reason. Such small and asymptomatic angiomyolipoma may need only wait and watch approach. The size of tumor is regularly monitored by the physician.
However, surgery is needed for a growing tumor. In such case the tumor is completely removed. During surgery a part of kidney may also have to be removed depending on the area of kidney invaded. The other method is tumor embolization. In this supply of blood is blocked causing eventual destruction of the tumor. Nowadays newer drugs are available that may help to treat the condition conservatively.