Padding one’s resume is not terribly uncommon, but former Yahoo! CEO Scott Thompson learned the hard way that it’s never a good idea — after just four months on the job, he’s stepped down from his position after it came to light that he didn’t have the degree he claimed to have.

Thompson’s Yahoo bio claims he holds a bachelor’s degree in both accounting and computer science from Stonehill College, while his degree is actually only in accounting.

That may not seem like such a big deal, but since he had to personally (and legally) swear the bio that appeared in Yahoo’s annual report was truthful, a bit of a scandal erupted when activist shareholder group Third Point discovered last week that Thompson, 54, hadn’t been completely honest about his credentials.

In a statement released on Sunday, Yahoo! confirmed Thompson “has left the company” and will be replaced by Yahoo media chief Ross Levinsohn as interim CEO. Before resigning over the weekend, Thompson also disclosed to Yahoo’s board of directors and several colleagues that he’s been diagnosed with thyroid cancer, something sources say played a role in his decision to step down.

[CNN]