Ousted Yahoo! chief executive Scott Thompson told board members before his resignation that he has cancer, the Wall Street Journal reported Monday.
Thompson, who quit amid a controversy over inaccurate academic credentials, said the diagnosis played a role in his decision to step down, but that he did not want to publicly disclose his thyroid cancer, the newspaper said.
He resigned amid a probe into why he had inaccurately stated he had a computer science degree.
The newspaper said Thompson, 54, reached an agreement to resign with some severance pay.
Five current board members, including director Roy Bostock and Patti Hart, will step down immediately and not end their terms at this year's annual shareholders meeting as originally planned, according to Yahoo!.
Thompson left a job as head of online payments firm PayPal, a key unit of Internet auction powerhouse eBay, to take the Yahoo! helm.
Under Thompson, Yahoo! dumped products along with workers in a quest to put the company back on course.
Yahoo! said in April that it would slash some 2,000 jobs in a purge aimed at becoming a "smaller, nimbler, more profitable" company.
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