According to a statement released by the team, Lindblom was diagnosed with Ewing sarcoma, a disease that forms in the bones or soft tissue.
Lindblom will undergo further testing and evaluation next week and will begin treatment immediately thereafter, the team said.
"The Flyers will do everything possible to support Oskar and assist him in securing the best care available," according to a statement from General Manager Chuck Fletcher.
According to cancer.gov, Ewing sarcoma is most common in adolescents and young adults through the mid-20s. Lindblom is 23 years old.
Lindblom has 11 goals and 7 assists in 30 games with the Flyers this season, tied for the team lead in goals with Travis Konecny. He missed their last game with what the team called an upper body injury.
He had 17 goals and 16 assists last season, his first full campaign in the NHL. For his career, he has 30 goals and 27 assists in 134 games, all with the Flyers, who drafted the Swedish native No. 138 overall in 2014.