Kidney cysts

Kidney cysts are round, fluid-filled blisters that form in one or both kidneys.

Kidney cysts can be of two types, depending on the form and number:

  1. Simple cysts
  2. Complicated cysts


Simple cysts

Simple cysts are benign (non-carcinogenic).

The kidney cysts are oval or spherical formations that contain an aqueous fluid. They are benign and often asymptomatic.
The most common symptoms of kidney cysts are increased blood pressure, back pain, left-sided or right-sided flank pain, urinary tract infections, etc. If numerous cysts occur in both kidneys, it is called multiple bilateral kidney cysts.

In general, these structures form in the cortical area of the kidney, i.e. on the outer wall or in the parenchyma, only rarely are they medullary (located inside).
This may include parapelvic cysts that form in the renal sinus, which is the area closest to the renal pelvis.

Simple kidney cysts are called hyperdense cysts when there is blood on the walls.

Most people over the age of 50 suffer from it, but often don’t know they have these cysts.

Complicated cysts

Complicated cysts are malignant (carcinogenic) and require immediate treatment.
People over the age of 50 have a higher risk of developing this disease.

Complicated cysts are characterized by an irregular wall. They may have septa (partition walls within the cyst) and calcifications (calcium deposits) and may be permeated by vessels.

Complicated kidney cysts and tumors
The urologist can use the method according to Bosniak to classify the risk of the kidney cyst turning into a tumor.
This method uses molecular biology, the imaging of cysts in CT using contrast medium, ultrasound or magnetic resonance imaging.
The classification according to Bosniak type I, II, III and IV assigns complex kidney cysts respectively 0%, 15.6%, 65.3% and 91.7% probability of being associated with kidney cancer.
Usually, complex cysts of the classification Bosniak type IV indicate kidney cancer.

Classification of kidney cysts according to Bosniak

  • Type I or benign cyst: Describes a benign simple cyst without partitions or solid proportions. It has thin and well-defined walls that have no limescale (calcification).
    It has the density of water and does not absorb contrast liquid.
  • Type II or probably benign: Describes a benign cyst that may include several thin partitions with calcium deposit. The cyst has well-circumscribed lesions that cannot be visualized with the help of contrast agent. These lesions are smaller than 3 cm and indicate abnormal structural changes. The cyst wall may have calcifications.
  • Type III can be benign or malignant: Describes cysts crisscrossed by thin partitions.
    Cyst wall and septa may have thickening or dense and nodular calcifications. However, the cyst does not absorb contrast fluid, since there are no soft tissues inside it.
  • Type IV or malignant cyst: Shows lesions in the form of solid tissue portions. The walls of the cyst and septa are thickened. Contrast agent is absorbed.

Classification by affected area

Exophytic kidney cyst

This is a cystic formation that develops inside the organ and penetrates to the outside as a result of the accumulation of fluid.
They can occur with 2 types of cysts: the first type is a simple, fluid-filled kidney cyst with a thin wall and even edges. The cyst contains only clear or pale yellow fluid. It does not pose a future risk to kidney cancer and patients can breathe a sigh of relief.
The second type is a complicated kidney cyst, which is the opposite of the previously mentioned, since it has an irregular wall and shape.

medullary cysts

These are small cysts that are located in the renal medulla, i.e. inside the organ.
They occur in both kidneys at the same time, and can lead to renal insufficiency in the long term.
The therapy consists of dialysis.

Polycystic kidney

Bilateral kidney cysts are located in both kidneys and mainly affect people over the age of 50.

After a few years of growth inside the kidneys, the cysts occupy all the available space and colonize it. This is a dangerous condition that affects the kidney’s ability to eliminate waste products from the body.
The accumulation of these waste products becomes extremely toxic to the body. This acts like a poison and humans may need dialysis or a kidney transplant.

Infantile form of polycystic kidney
Hundreds of cysts form everywhere in the kidney of children or newborns.

Adult form of polycystic kidney
As with infantile kidney disease, hundreds of cysts form groups and populate the inside of the kidney.
Most often, this form is caused by
If the polycystic kidney is dysplastic, it means that the cysts have replaced part of the kidney structure, but the growth of these cysts does not constitute a tumor.

Symptoms of kidney cysts

Usually, simple cases are asymptomatic and are not noticed.

Possible symptoms of simple kidney cysts include:

  • frequent urinary tract infection;
  • pain in the right or left flank, depending on which kidney is affected;
  • Fever;
  • Ague;
  • blood in the urine;
  • hypertension or hypertension;
  • Backache.

Most often, these symptoms are perceived when the cyst becomes larger.

Voluminous cysts can press on other abdominal organs and impair their functions.

Sometimes these cysts break open and cause mild to severe symptoms.
Symptoms of ruptured kidney cysts include:

  • blood in the urine (hematuria);
  • abdominal and back pain;
  • pain in the abdomen and flanks;
  • Sepsis;
  • Hemorrhage.

In severe cases, ruptured kidney cysts can hinder blood flow to some areas of the kidney, causing damage.

Diagnosis of kidney cysts

When ultrasound of a cyst, one can find an anechoic area filled with fluid and therefore does not send an echo to the transducer of the ultrasound probe.
Even low-echo areas are characterized by an accumulation of liquid, while echo-rich areas are solid and appear as a white spot in the image of the ultrasound.
In general, echo-rich images represent a tumor, but not always.
Even a low-echo area can indicate a malignant structure.

The doctor may order a CT scan or magnetic resonance imaging for further investigation.
If the doctor suspects a malignant cyst, a biopsy is performed to study the cell composition.

Therapy for kidney cysts

Asymptomatic simple kidney cysts (the only symptom is pain) do not require therapy.

When to operate?
However, complicated kidney cysts have an increased risk of turning into a tumor, which is why immediate treatment is required.
For therapy, the following methods are used:

Sclerotherapy and aspiration
Usually, this form of therapy is used in patients with varicose veins or hemorrhoids, but research has shown that it also works for kidney cysts.
In this procedure, the cyst is pierced with a long sterile needle and the fluid is drained to reduce it.
Then the cyst is filled with an alcohol-containing solution (usually ethanol), which hardens the tissues.
This is done under local anesthesia and can be used well for small cysts.
For infected cysts, the appropriate treatment is percutaneous drainage and therapy with antibiotics.

Laparoscopic decoration of the cyst
Small incisions are made into the cyst, and then filled with gas. This operation destroys the cyst and prevents recurrences. This procedure is used only if the suction method has not given positive results.

Natural remedies and nutrition for kidney cysts

Kidneys have the task of removing waste products from the body. Therefore, a diet without too much protein, fats, sodium and phosphorus is recommended.

Salt is harmful, especially if you suffer from renal insufficiency.
Many people think that sodium is only found in spices and salted foods (French fries, etc.), however, desserts and carbonated drinks also contain a lot of it.
You should avoid cookies and cakes, drinks such as Coca Cola, Sprite, etc. are also harmful.
A diet with plenty of fresh and dried fruits, vegetables, legumes, nuts, almonds, chia seeds and other plant products is very good for keeping the kidneys healthy.

Read more: