"Stan has been diagnosed with an early base of tongue cancer and the prognosis is excellent," Dr. Richard Borrowdale of Loyola Medical Center, who is treating Stan.
"He will be treated with external beam radiation therapy."
The 71-year-old Mikita had 541 goals and 926 assists in a 21-season career, all with Chicago.
He won the Stanley Cup in 1961 and the Hart Trophy as the league's MVP in 1967 and 1968 with Chicago. Mikita is also the first player in NHL history to win the Art Ross, Hart and Lady Byng trophies in the same season in 1966-67.
The nine-time all-star had his No. 21 retired by the team in 1980.