Microsoft Co-Founder Paul Allen Has Cancer

SEATTLE (TheStreet) -- Microsoft's(MSFT Quote) co-founder Paul Allen has been diagnosed with non-Hodgkin's lymphoma and is undergoing treatment.

Allen's sister, Jody Allen, who is CEO of his investment firm Vulcan, said the 56-year-old received the diagnosis early this month, the Associated Press reports. According to a memo to Vulcan employees, Paul Allen has diffuse large B-cell lymphoma, a relatively common form of lymphoma.

"Paul is feeling OK and remains upbeat," Jody Allen said. "He continues to work and he has no plans to change his role at Vulcan."

Allen co-founded Microsoft with Bill Gates in 1975. He resigned as an executive in 1983. He was diagnosed with Hodgkin's disease in 1983 but his cancer was successfully treated, according to Reuters.

Allen's net worth at last count totaled about $11.5 billion, AP reports, making him one of the richest people in the world.

Allen also is chairman of cable company Charter Communications.

-- Reported by Joseph Woelfel in New York .

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