If there’s one way that 11-year-old Cristian Muñoz would describe himself, it would be an athlete. Cristian has always been drawn to playing sports: the rigor, the competition, the connection with friends. It was also through sports—football, to be exact—that Cristian experienced the first symptoms of Wilms’ tumor, a rare kidney cancer. 

According to the Contra Costa Herald, Cristian fell during a game when pain ripped through his stomach. It became so severe that Cristian’s mother, Maria, had to come pick him up from school. By that night, Cristian was in the emergency room; the pain just would not subside. Testing showed that Cristian was experiencing internal bleeding. 

Further testing and examination found that Cristian had a Wilms’ tumor—and frighteningly, the tumor had ruptured during the fall. Wilms’ tumors are already quite rare; they predominantly affect children under five years old, with the incidence significantly falling with age. So Cristian not only had a rare cancer, but was considered an ever rarer patient! 

Eventually, Cristian underwent surgery—as well as chemotherapy and radiation—to treat his tumor. Maria shares that this journey has been frightening and overwhelming at times, but she is so thankful for the support that her family has received. 

Cristian, meanwhile, does his best to keep his chin up and mind positive throughout his experience. He loves spending time with his three siblings, playing Xbox, and listening to music. Although he can’t play sports now, he aspires to get back on the field in the future. In the meantime, he hopes to inspire other children on their journey and let them know that they aren’t alone. 

What is Wilms’ Tumor?

Wilms’ tumor, which is also known as nephroblastoma, is a rare kidney cancer. However, it is also considered to be the most common form of kidney cancer in children. Typically, Wilms’ tumor only affects one kidney (although it may form in both). Without treatment, this cancer may metastasize (spread) to other areas of the body. 

While the exact cause of Wilms’ tumor is unknown, many believe that heredity plays a role. Other risk factors include being African-American, having a family history of Wilms’ tumors, or being born with aniridia, Beckwith-Wiedmann syndrome, WAGR syndrome, or hemihypertrophy. 

Symptoms of this cancer may, but do not always, include:

• An abdominal mass that can be seen or felt
• Blood in the urine (hematuria)
• Fever
• Fatigue
• Constipation
• Abdominal pain and swelling
• Nausea and vomiting
• Appetite loss
• Shortness of breath
• High blood pressure 
• Large and swollen veins across the abdomen 

The overall cure rate of Wilms’ tumor is 85%. Treatment options include proton therapy, radiation, surgery, and chemotherapy. Children will be cared for by multidisciplinary teams.