What is Medullary Sponge Kidney?
Medullary sponge kidney, also known as Cacchi-Ricci disease, is a birth defect where changes occur in the tubules, or tiny tubes, inside a fetus’ kidneys.
In a normal kidney, urine flows through these tubules as the kidney is being formed during a fetus’ growth. In medullary sponge kidney, tiny, fluid-filled sacs called cysts form in the tubules within the medulla—the inner part of the kidney—creating a spongelike appearance. The cysts keep urine from flowing freely through the tubules.
Symptoms of medullary sponge kidney do not usually appear until the teenage years or the 20s. Medullary sponge kidney can affect one or both kidneys.
What causes Medullary Sponge Kidney?
Scientists do not fully understand the cause of medullary sponge kidney or why cysts form in the tubules during fetal development. Even though medullary sponge kidney is present at birth, most cases do not appear to be inherited.
How common is Medullary Sponge Kidney?
Medullary sponge kidney affects about one person per 5,000 people in the United States. Researchers have reported that 12 to 20 percent of people who develop calcium-based kidney stones have medullary sponge kidney.1
Who is more likely to develop Medullary Sponge Kidney?
Medullary sponge kidney affects all races and geographic regions. Among people who are more likely to develop calcium-based kidney stones, women are more likely than men to have medullary sponge kidney.2
Medical and Family History
Taking a medical and family history can help diagnose medullary sponge kidney. A health care provider will suspect medullary sponge kidney when a person has repeated UTIs or kidney stones.
Physical Exam
No physical signs are usually present in a patient with medullary sponge kidney, except for blood in the urine. Health care providers usually confirm a diagnosis of medullary sponge kidney with imaging studies.
Intravenous Pyelogram
In an intravenous pyelogram, a health care provider injects a special dye, called contrast medium, into a vein in the patient’s arm. The contrast medium travels through the body to the kidneys. The kidneys excrete the contrast medium into urine, which makes the urine visible on an x-ray. An x-ray technician performs this procedure at a health care provider’s office, an outpatient center, or a hospital. An intravenous pyelogram can show any blockage in the urinary tract, and the cysts show up as clusters of light.
Computerized Tomography Scans
Computerized tomography scans use a combination of x-rays and computer technology to create images. For a CT scan, a health care provider may give the patient a solution to drink and an injection of contrast medium. CT scans require the patient to lie on a table that slides into a tunnel-shaped device where the x-rays are taken. An x-ray technician performs the procedure in an outpatient center or a hospital. CT scans can show expanded or stretched tubules.
Ultrasound
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. Ultrasound can show kidney stones and calcium deposits within the kidney.
Curing an Existing Urinary Tract Infection
To treat a UTI, the health care provider may prescribe a medication called an antibiotic that kills bacteria. The choice of medication and length of treatment depend on the person’s medical history and the type of bacteria causing the infection.
Clinical Trials
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.
What are clinical trials, and are they right for you?
Clinical trials are part of clinical research and at the heart of all medical advances. Clinical trials look at new ways to prevent, detect, or treat disease. Researchers also use clinical trials to look at other aspects of care, such as improving the quality of life for people with chronic illnesses. Find out if clinical trials are right for you NIH external link.