Kidney cysts


What is it about ?

A cyst is a cavity surrounded by a wall and filled with air or liquid (water, blood, mucus, etc.). When it is located in the kidney, it is called a renal cyst.

Solitary cyst

When the cyst is alone, it is called a “solitary cyst”. It frequently appears in the elderly. Often, it is discovered by chance. If the ultrasound shows it’s a benign cyst, it’s completely harmless. There is no need to follow up.

Polycystic kidneys

If the kidneys contain more than one cyst, it is called a polycystic kidney. This is an inherited condition that:

  • may already be present at birth (infant form);
  • does not appear until later (autosomal dominant polycystic kidney disease) (PKRAD).

This form is ten times more common than the infantile form. “Autosomal dominant” means that the children of those affected have a one in two chance of inheriting the disease.

Other symptoms

Polycystic kidneys are often accompanied by hypertension. Kidney function gradually deteriorates. As a result, less urine is formed and wastes are insufficiently removed from the blood. In the advanced stage of the disease, kidney dialysis will be necessary in some people.

Sometimes cysts appear in other places of the body. With kidney cysts, there is an increased risk of deformation of the blood vessels in the brain (aneurysms). These thin-walled blood vessels swell like a balloon under pressure and can burst suddenly.

What is its frequency?

About 1 in 2 people over the age of 50 have a solitary kidney cyst.

The infantile form of polycystic kidney disease affects 1 in 40,000 newborns.
The autosomal dominant form is found in 1 in 1,400 adults.

How to recognize it?

Solitary cyst

The solitary kidney cyst usually does not cause any symptoms. Sometimes there is a vague pain in the side. This is due to the pressure when the cyst gets bigger.

Polycystic kidneys
Infant form

The infantile form of the disease is usually discovered at birth, and the most severe cases can already be discovered at the end of pregnancy. Mild forms are only discovered during childhood or adolescence.

Autosomal dominant form

Most people with the autosomal dominant form have few symptoms at the onset of the disease. Often the diagnosis is made during a screening exam done because a family member has the condition.

Symptoms appear at different times depending on the person, on average around the age of 35. The two most common symptoms are abdominal pain, especially in the flanks, and blood in the urine. Some patients have a feeling of heaviness in the stomach. There may also be urinary tract infections and kidney stones.

How is the diagnosis made?

Solitary cyst

The solitary cyst is usually discovered by chance during an ultrasound of the belly.

Polycystic kidneys
Infant form

The infantile form is usually discovered when the baby is examined.

Autosomal dominant form

The autosomal dominant form is usually found during a screening test done because a family member has the condition. The most important examination is the ultrasound of the kidneys. The presence of a number of cysts at a certain age leads to the diagnosis.

It is recommended that this screening test be performed only after the age of 18. In children of those affected, blood pressure should be checked every three years.

What can the doctor do?

Solitary cyst

Benign solitary cyst does not require treatment or follow-up.

Polycystic kidneys

Unfortunately, there is no cure for polycystic kidneys. It is therefore essential that proper follow-up is carried out to keep the disease under control.

  • The doctor will closely monitor the progress.
  • Hypertension must be treated.
  • It is very important to maintain a healthy lifestyle.
  • In severe cases with rapid progression, tolvaptan, a medicine that slows the progression of the disease, can sometimes be given. Only certain patients can benefit from it.
  • When renal function is too impaired, the patient is put on dialysis.
  • In the terminal stage, the only solution is a kidney transplant.

To know more ?

    Source

    Foreign clinical practice guide ‘Renal cysts’ (2000), updated 23.01.2017 – ebpracticenet