"I still tell people I went third overall in the sixth round," he said. "I've definitely come a long way."
Atkinson led Columbus in scoring the past two seasons, including NHL career highs of 35 goals, 27 assists and 62 points last season.
"To lock up a core player like that for the next seven years is obviously a big deal for our team," general manager Jarmo Kekalainen said.
Atkinson has six points (four goals, two assists) in 15 games this season, earning $3.5 million ending a three-year contract.
"The later you go, the unrestricted free agents, the more you risk he's probably going to walk into the free agency and you get nothing," Kekalainen said. "So, a player of this caliber, if we couldn't reach a deal, would probably be traded so that we wouldn't be wasting an asset.
"There's always, of course, another option you consider, that you sort of rent him to yourself if you're having a very successful season, you're gearing up for the [Stanley Cup] Playoffs and you know for sure that you're going to be there. But at the same time, we're a young team and we're building and it's important to retain the assets that we have and keep our core together."