SAN DIEGO -- Tony Gwynn, the prolific-hitting Hall of Fame outfielder who spent his entire 20-year career with the Padres, has been diagnosed with cancer of a salivary gland.

Gwynn, a 15-time All-Star voted into the Hall in the first year he was eligible in 2007, has had three procedures since 1997 to remove non-cancerous tumors to the largest salivary gland, he told the San Diego Union-Tribune.

But the latest operation last month discovered a malignant growth, he said.

"They took out three lymph nodes and did all the tests and the results showed cancer in the parotid," Gwynn told the newspaper Friday.

The 50-year-old Gwynn faces radiation and chemotherapy treatments. He says doctors have told him they feel they caught the cancer early and "there was not much of it there."

"They say this is a slow-moving but aggressive form of cancer," Gwynn told the Union-Tribune from his Poway home. "I'm going to be aggressive and not slow-moving in treating this."

Gwynn said he faces up to two months of radiation treatments, which he will undergo five times a week. He said he will have chemotherapy treatments once a week.

"I go in Monday for a consultation and I hope to immediately begin the treatments," Gwynn told the newspaper.

Gwynn said he thought the cancer was most likely related to his use of chewing tobacco throughout his career.

"I haven't discussed that with the doctors yet, but I'm thinking it's related to dipping," said Gwynn, who said he had failed to drop the habit despite the previous mouth procedures.

Dr. Kevin Brumund, a neck and throat specialist at the UCSD Moores Cancer Center, told the newspaper there have been no studies linking parotid cancer and chewing tobacco, which is now banned in minor league baseball.

Gwynn is San Diego State's baseball coach, and the school confirmed Gwynn's condition to The Associated Press. Gwynn plans to return to his alma mater, which he has coached since 2003.

Gwynn's son, Tony Gwynn Jr., is a reserve outfielder for the Padres. This year was his second full big-league season.

Gwynn, who ranks 19th in MLB history as a career .338 hitter, is 18th in hits with 3,141.

Gwynn debuted in 1982 and appeared in his first of two World Series two years later during his first full season. The Padres fell to the Detroit Tigers in five games.

San Diego returned 14 years later but was swept by the New York Yankees. Gwynn retired three years later.

Gwynn told the Union-Tribune he had purposely held off going public about the procedures and was successful thanks to recurring back trouble.

"My back wasn't letting me to do anything and was keeping me away from the ballpark and the TV booth, so it was pretty easy not to say anything," Gwynn said. "Although the back is still an issue, it is getting better. Right now, the back feels good. I can stand up.

"But I had to be upfront with my team about the cancer."

Information from The Associated Press was used in this report.