Pediatric kidney tumors

What are pediatric kidney tumors?

Kidney tumors are rare in children, with Wilms tumor (nephroblastoma), occurring most often. Most children with Wilms tumors can be cured, but with Wilms tumors and other rare kidney tumors, it is important to preserve as much of the child’s renal function as possible. Because these cancers are so rare, children who have them should be cared for by a multidisciplinary team of pediatric specialists.

What are the different types of pediatric kidney tumors?

• Wilms tumor - most common type and can be bilateral. Wilms tumors can metastasize to the lungs and liver. The tumors typically are diagnosed in children aged 2 to 4 years old.

• Cystic partially differentiated nephroblastoma - an uncommon form of Wilms tumor and is comprised of cysts.

• Clear cell carcinoma - can spread from the kidney to the lung, brain, bone or soft tissue.

• Renal cell carcinoma - this type of kidney tumor is rare in children younger than age 15 and occurs more often in adolescents and young adults aged 15 to 19. It can metastasize easily to the lungs, bones and liver.

• Congenital mesoblastic nephroma - the most common kidney tumor in newborns and infants, particularly boys. It is highly curable, and one type can be seen on fetal ultrasound.

• Rhabdoid tumor of the kidney - occurs primarily in infants and younger children. The aggressive tumor can metastasize to a child’s lung and brains and often is advanced when diagnosed.

• Anaplastic sarcoma of the kidney - a rare sarcoma that occurs in children or adolescents younger than age 15. It can spread to the lungs, liver and bones.

What are the signs and symptoms of pediatric kidney tumors?

Symptoms can vary, but many children have a swollen abdomen or large mass in the abdomen. Pain, blood in the urine and unexplained fever are other signs of kidney tumors.

How are pediatric kidney tumors diagnosed?

Any child with a renal mass should be assessed for possible associated syndromes.

• Ultrasound

• Computed tomography (CT)

• Lab work - A complete blood count, liver or renal function tests and urinalysis can aid in differential diagnosis.

What are the causes of pediatric kidney tumors?

As we learn more about genetic predisposition to kidney tumors, we can better predict and screen for risk of renal cancer among children and adolescents. Certain genetic syndromes predispose children to Wilms tumors and renal cell carcinoma, in particular.

Knowing that a child is at high risk for kidney tumors can help detect the cancer early and help preserve kidney function.

How are pediatric kidney tumors treated?

Treatment of Wilms tumors is complex, requiring involvement of a multidisciplinary team of pediatric subspecialists. Because kidney tumors are rare, children should be considered for enrollment in a clinical trial when possible.

Treatment may include:

• Nephrectomy (kidney removal)

• Radiation therapy

• Chemotherapy

• Biologic therapy as appropriate

Children with advanced disease may require high-dose chemotherapy, with a stem cell or kidney transplant.