What Are Kidney Cysts in Children?

Multiracial siblings on playground smiling at camera

Kidney cysts are round, fluid-filled pouches that develop in the kidneys. In most cases, cysts are small and asymptomatic, and no treatment is needed. Simple kidney cysts are usually discovered during an ultrasound for a different condition.

However, these types of cysts are uncommon in children, so a cyst could be an indication of something more serious. Even if a cyst is not causing symptoms, it is important to evaluate and monitor kidney cysts in children.

Types of Kidney Cysts

Simple Kidney Cysts

Simple kidney cysts are small, usually less than 1 inch in diameter, and they don’t usually cause any symptoms. They are common in older people, but rare in children. Their cause is unknown, and they usually don’t need any treatment. Occasionally, a simple cyst can be large enough to affect function. For example, if a cyst is located close to the ureter opening, it could obstruct urine from flowing from the kidney to the bladder. This can cause a urinary tract infection (UTI) or kidney stones. In rare cases, a simple cyst can also become infected or burst.

Complex Kidney Cysts

Complex kidney cysts are cysts that have more than one fluid pocket. Instead of one fluid-filled pouch, complex cysts have multiple pouches of fluid, like a bunch of grapes. Like simple cysts, these are usually asymptomatic and don’t need treatment. However, a complex cyst indicates a higher risk of cancer than a simple cyst.

This type of cyst should be monitored to make sure it’s not growing larger over time. Like simple cysts, it’s possible — but unlikely — for complex cysts to become infected or burst.

Multicystic Dysplastic Kidney

Multicystic dysplastic kidney is a condition where one kidney didn’t form correctly during fetal development. Although it can be genetic, it usually occurs randomly. In multicystic dysplastic kidney, or MCDK, one kidney is formed of cysts and scar tissue instead of functioning structures. However, typically the other kidney is normal, so this condition causes no symptoms and requires no treatment. Usually, the non-functioning kidney will regress and disappear over time. The other kidney will perform all renal functions for the body.

Polycystic Kidney Disease

Polycystic kidney disease, or PKD, is a serious genetic disease that causes cysts to form in the kidneys. There are two types: autosomal dominant PKD and autosomal recessive PKD.

Autosomal recessive PKD is very rare, occurring about 1 in every 200,000 births. However, this type is more likely to cause symptoms during childhood. It causes multiple cysts to form in both kidneys and in the liver, and it’s usually diagnosed by fetal ultrasound, before the baby is born. It causes progressive kidney failure as both kidneys’ functioning tissue is gradually replaced by cysts. Symptoms could include high blood pressure, swollen belly, recurring UTIs, and back or side pain.

Autosomal dominant PKD causes large kidneys with multiple cysts. Cysts can also occur in the liver. Although this condition is also genetic, symptoms don’t usually develop until the person is between 30 and 50 years old. It’s rare to diagnose this condition in children, since it’s usually asymptomatic until later in life.

Diagnosis and Testing

Kidney cysts can be detected from imaging tests such as:

Asymptomatic kidney cysts are often found during a scan for another unrelated condition.

Treatment of Cystic Kidneys

Kidney cysts that are not causing symptoms do not require any treatment. If the location or size of the cyst causes it to block the ureters or otherwise affect kidney function, then it can be punctured and drained to reduce the size. This procedure, called sclerotherapy, can be done with local anesthesia and does not usually require an overnight hospital stay. In rare cases, a large kidney cyst may need to be surgically removed.

If a cyst becomes infected, it is usually treated with antibiotics. An infected cyst that does not respond to antibiotics may need to be removed or drained.

Your child’s pediatric nephrologist and/or urologist will work together to decide whether to remove a kidney cyst. Complex cysts or large simple cysts may need to be monitored to make sure they are not growing over time.

Children with polycystic kidney disease may need kidney dialysis or a kidney transplant in childhood.

If your child has a cystic disorder of the kidneys, talk to your pediatric nephrologist to create a long-term treatment plan.

Patient Stories

  • “Quite honestly, it was the luckiest day of our lives.”

    Stephanie and Dan
    Read More
  • We are, and will always be thankful for all of the medical interventions during the last 10 days of my pregnancy and Max’s 77-day NICU stay at Cooperman Barnabas Medical Center!

    Max
    Read More
  • "The progress Nikos has made is just incredible."

    Nikos
    Read More

Patient Stories

  • Watch Testimonial
  • Watch Testimonial
  • Watch Testimonial
Cooperman Barnabas Medical Center
94 Old Short Hills Road
Livingston, NJ 07039
(973) 322-5000
View
Monmouth Medical Center
300 Second Avenue
Long Branch, NJ 07740
(732) 222-5200
View
The Unterberg Children's Hospital at Monmouth Medical Center
300 2nd Avenue
Long Branch, NJ 07740
(732) 923-7250
View
Medical Specialty Services at Bayonne
16 East 29th Street
Bayonne, NJ 07002
(973) 926-7280
View
The Family Health Center (FHC) at Newark Beth Israel Medical Center
166 Lyons Avenue
Newark, NJ 07112
(973) 926-7300
View
Clara Maass Medical Center
1 Clara Maass Drive
Belleville, NJ 07109
(973) 450-2000
View
Community Medical Center
99 Highway 37 West
Toms River, NJ 08755
(732) 557-8000
View
Newark Beth Israel Medical Center
201 Lyons Avenue at Osborne Terrace
Newark, NJ 07112
(973) 926-7000
View
Children's Hospital of New Jersey at Newark Beth Israel Medical Center
201 Lyons Avenue at Osborne Terrace
Newark, NJ 07112
(973) 926-7000
View
Barnabas Health Ambulatory Care Center
200 South Orange Avenue
Livingston, NJ 07039
(973) 322-7000
View
The Pediatric Specialty Center at Cooperman Barnabas - West Orange
375 Mount Pleasant Avenue
Suite 105
West Orange, NJ 07052
(973) 322-6900
View
Jersey City Medical Center
355 Grand Street
Jersey City, NJ 07302
(201) 915-2000
View
Jersey City Medical Center's Ambulatory Care Center
395 Grand Street
Jersey City, NJ 07304
(201) 915-2410
View
The Jersey City Family Health Center
418 Summit Ave
Jersey City, NJ 07306
(201) 499-1969
View
Jersey City Medical Center at Greenville
1825 John F. Kennedy Boulevard
1st Floor
Jersey City, NJ 07305
(201) 395-7600
View
The Bristol-Myers Squibb Children's Hospital at RWJUH
200 Somerset Street
New Brunswick, NJ 08901
(732) 828-3000
View
Children's Specialized Hospital Outpatient Center – Bayonne
815 Broadway
Bayonne, NJ 07002
(201) 823-6010
View
Children's Specialized Hospital Outpatient Center – Egg Harbor Township
6106 Black Horse Pike
Egg Harbor Township, NJ 08234
(609) 645-7779
View
Children's Specialized Hospital Outpatient Center – Hamilton
3575 Quakerbridge Road
Hamilton Township, NJ 08619
(609) 631-2800
View
Children's Specialized Hospital Long Term Care Center – Mountainside
150 New Providence Road
Mountainside, NJ 07092
(908) 233-3720
View
Children's Specialized Hospital Outpatient Center – Newark
182 Lyons Avenue
Newark, NJ 07112
(973) 391-2960
View
Children's Specialized Hospital Outpatient Center – Toms River Lakehurst Road
368 Lakehurst Road
Toms River, NJ 08755
(732) 281-3900
View
Children's Specialized Hospital Outpatient Center – New Brunswick Plum Street
10 Plum Street
6th Floor
New Brunswick, NJ 08901
(732) 258-7100
View
Children's Specialized Hospital
200 Somerset Street
New Brunswick, NJ 08901
(888) 244-5373
View
RWJ University Hospital Hamilton
1 Hamilton Health Place
Hamilton, NJ 08690
(609) 586-7900
View
Robert Wood Johnson University Hospital
1 Robert Wood Johnson Place
New Brunswick, NJ 08901
(732) 828-3000
View
Children's Specialized Hospital Outpatient Center – East Brunswick
629 Cranbury Road
East Brunswick, NJ 08816
(732) 258-7040
View
Children's Specialized Outpatient Center at Toms River Stevens Road
94 Stevens Road
Toms River, NJ 08755
(732) 914-1100
View
Children's Specialized Hospital Outpatient Center at Jersey City
1825 John F. Kennedy Boulevard
Jersey City, NJ 07305
(201) 408-6100
View

Pediatrics Treatment & Care

offered at these locations in your neighborhood

View All Locations