Microsoft co-founder Paul Allen has been diagnosed with non-Hodgkin’s lymphoma, more than 25 years after he was treated for Hodgkin’s disease, a spokesman at his Seattle-based company Vulcan Inc. said.

In a memo to Vulcan employees, CEO Jody Allen said that the 56-year-old Paul Allen “received the diagnosis early this month and has begun chemotherapy.” On Monday evening, the memo was posted at CNET’s news site.

Jody Allen, who is Paul Allen’s sister, said in the memo, “Doctors say he has diffuse large B-cell lymphoma, a relatively common form of lymphoma. This is tough news for Paul and the family. But for those who know Paul’s story, you know he beat Hodgkin’s a little more than 25 years ago, and he is optimistic he can beat this, too.”

Paul Allen is feeling OK, is still working and “has no plans to change his role at Vulcan,” the memo said.

(article and photo source: CNN)