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.
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.
Wilms tumor, which is the most common type and can be bilateral. Wilms tumors can metastasize to the lungs and liver. The tumors typically develop in children age 3 to 4 years old.
Cystic partially differentiated nephroblastoma, an uncommon form of Wilms tumor comprising cysts.
Clear cell carcinoma, which can spread from the kidney to the lung, brain, bone or soft tissue.
Renal cell carcinoma, which is rare in children younger than age 15, but occurs more often in adolescents and young adults age 15 to 19. It can metastasize easily to the lungs, bones and liver.
Congenital mesoblastic nephroma, the most common kidney tumor of newborns and infants, particularly boys. It is highly curable and one type can be seen on fetal ultrasound.
Rhabdoid tumor of the kidney, which 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.
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.
Abdominal imaging with ultrasonography, radiography and computed tomography (CT) can help detect kidney tumors. A complete blood count, liver or renal function tests and urinalysis can aid in differential diagnosis.
Any child with a renal mass should be assessed for possible associated syndromes.
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:
Children with advanced disease may require high-dose chemotherapy with a stem cell or kidney transplant.