Children's Hospital Los Angeles said Lauren Hammersley taped a message to the window of the hospital room of her 2-year-old daughter, Hazel, reading, "Send Pizza. RM 4112," and a picture of the sign was posted Saturday to website Reddit, CNN reported Tuesday.
Reddit users decided to use the opportunity for one of the website's "Random Acts of Pizza," which aim to "restore faith in humanity, one slice at a time."
Hospital officials released a statement after more than 20 pre-paid pizzas arrived at the facility.
"You've made a little girl very happy but NO MORE PIZZA IS NEEDED," the hospital said. "The Hammersley family will be going to bed very full and very thankful for the compassion they received today."
Lauren Hammersley posted on her blog, "Our Little Hazelnut," that other children and families in the ward were able to enjoy the pizza.
"Several other children and nurses came into the room, with music playing, and had themselves a wonderful Pizza Party," she said.
Hazel was diagnosed in April with Stage 3 neuroblastoma, a cancer most common in infants and young children.
"We have been absolutely humbled and surprised by the outpouring of love and support from the online community and can only hope and pray that this brings awareness to neuroblastoma and the Childhood Cancer Community," Hammersley wrote on her blog.