Acquired Cystic Kidney Disease

Overview

Cystic kidney disease causes cysts (sacs of fluid) to form in or around the kidneys. There are many types of cystic kidney disease. Some are the result of abnormal genes; others develop in the womb or as a result of kidney failure. Both adults and infants can have cystic kidney disease. Treatment usually includes medication, dialysis or kidney transplant surgery.

Symptoms

Acquired cystic kidney disease differs from other forms of kidney diseases with cyst development in that it is fairly asymptomatic. The patient rarely feels much from the presence of the cysts in their kidneys. The kidney tends to remain the same size rather than expand due to the fluid filled sacs. Thus unlike polycystic kidney disease where the gradually expanding kidneys can be uncomfortable for the patient, an individual with the acquired cystic kidney disease can be oblivious to the structures developing inside them.

The presence of the cysts may become apparent should a cyst burst. This can cause the patient to feel pain or possibly develop a fever. Further investigation would then potentially reveal the cause. Signs of the disease can also include blood in the urine, a lump in the stomach, reduced appetite, pain at the side of the body, anemia and weight loss.

Another potential complication is that a cyst may become cancerous and cause renal cell carcinoma. This occurs in about 7% of cases, and the cancer is located in the tubules of the kidney. These are the structures that help to filter the blood from the kidney and create the urine that we excrete from our bodies.

The longer a person has dialysis, the higher the risk is of them developing renal cell cancer as a result of acquired cystic kidney disease as this disease becomes more likely with the length of time that a person experiences end stage renal disease.

Causes

The initial kidney failure, also known as end stage renal disease, that triggers the development of acquired cystic kidney disease can be caused by a number of different triggers such as diabetes, lupus, heart problems and urinary tract conditions. These diseases can result in permanent damage to the kidneys. Genetic diseases can also be implicated in the deterioration of the kidneys; however, acquired kidney disease is not by itself a hereditary disease.

Many researchers hypothesize that nephron loss of any etiology results in compensatory tubular cell hyperplasia in the intact nephrons. This response usually starts by activation of proto-oncogenes and release of various growth factors, which in turn accumulate in patients with chronic kidney insufficiency. Over a prolonged period of time, these factors then lead to tubular hyperplasia and subsequent cyst formation.

Regardless of such hypotheses, the causes of the cysts in acquired cystic kidney disease are not yet fully understood. The cysts only develop in the kidneys and nowhere else in the patient so are considered to occur as a result of activity in this area but this has not been proved. It has been suggested that they are a result of the build-up of waste products that the kidneys, with male hormones also playing a role. The lack of knowledge in the field means that the disease cannot currently be cured.

How is acquired cystic kidney disease treated?

If acquired cystic kidney disease is not causing complications, a person does not need treatment. A health care provider will treat infections with antibiotics—medications that kill bacteria.

What is acquired cystic kidney disease?

Acquired cystic kidney disease happens when a person's kidneys develop fluid-filled sacs, called cysts, over time. Acquired cystic kidney disease is not the same as polycystic kidney disease (PKD), another disease that causes the kidneys to develop multiple cysts.

How is acquired cystic kidney disease diagnosed?

A health care provider may diagnose a person with acquired cystic kidney disease based on

1.medical history

2.imaging tests

Medical History

Taking a medical history may help a health care provider diagnose acquired cystic kidney disease. A health care provider may suspect acquired cystic kidney disease if a person who has been on dialysis for several years develops symptoms such as fever, back pain, or blood in the urine.

Imaging Tests

To confirm the diagnosis, the health care provider may order one or more imaging tests. A radiologist—a doctor who specializes in medical imaging—interprets the images from these tests, and the patient does not need anesthesia.

1.Ultrasound uses a device, called a transducer, that bounces safe, painless sound waves off organs to create an image of their structure. A specially trained technician performs the procedure in a health care provider's office, an outpatient center, or a hospital. The images can show cysts in the kidneys as well as the kidneys' size and shape.

2.Computerized tomography (CT) scans use a combination of x-rays and computer technology to create images. For a CT scan, a nurse or technician may give the patient a solution to drink and an injection of a special dye, called contrast medium. CT scans require the patient to lie on a table that slides into a tunnel-shaped device where an x-ray technician takes the x-rays. An x-ray technician performs the procedure in an outpatient center or a hospital. CT scans can show cysts and tumors in the kidneys.

3.Magnetic resonance imaging (MRI) is a test that takes pictures of the body's internal organs and soft tissues without using x-rays. A specially trained technician performs the procedure in an outpatient center or a hospital. Although the patient does not need anesthesia, a health care provider may give people with a fear of confined spaces light sedation, taken by mouth. An MRI may include the injection of contrast medium. With most MRI machines, the patient will lie on a table that slides into a tunnel-shaped device that may be open-ended or closed at one end. Some machines allow the patient to lie in a more open space. During an MRI, the patient, although usually awake, must remain perfectly still while the technician takes the images, which usually takes only a few minutes. The technician will take a sequence of images from different angles to create a detailed picture of the kidneys. During the test, the patient will hear loud mechanical knocking and humming noises from the machine.

Sometimes a health care provider may discover acquired cystic kidney disease during an imaging exam for another condition. Images of the kidneys may help the health care provider distinguish acquired cystic kidney disease from PKD.

What causes cystic kidneys?

Kidney cysts occur when the tube of a nephron begins to get bigger and fill with fluid. Researchers don't know what causes this to occur, but they do know that simple cysts aren't inherited. It is believed that injury or microscopic blockages in the tubules may lead to the development of some simple kidney cysts.

How do you get acquired cystic kidney disease?

The chance of developing acquired cystic kidney disease increases with the number of years a person is on dialysis. However, the cysts are caused by CKD or kidney failure, not dialysis treatments. Acquired cystic kidney disease happens when a person's kidneys develop fluid-filled sacs called cysts.

What problems can kidney cysts cause?

However, in some cases simple kidney cysts can grow large enough and cause a dull pain in a person's back, side or upper abdomen. These cysts can also get infected, causing pain, fever and tenderness. They can burst, also causing pain. Simple kidney cysts rarely harm kidneys or impair their ability to function.

Should kidney cysts be removed?

If it has become large enough to cause pain, discomfort, or high blood pressure, it may need to be surgically removed. Some complex cysts may also be removed due to an increased risk of kidney cancer or because the patient is experiencing a decline in kidney function.