A native of Wigan, England, Paul played almost all his professional rugby league career with Warrington Wolves. He is married to Lyndsay and has four children, Ella (13), Georgia (11), Jack aged 7 and baby Harry who was born in October.
Commenting on the announcement, Munster head coach Tony McGahan said: "The news of Paul's illness has had a profound impact not only on the management and squad, but on everyone who have had any dealings whatsoever with the man.
"He's been an integral part of Munster Rugby, is tremendously well liked and respected and is far more than just a work colleague.
"His response to his illness has been nothing short of inspirational although not surprising perhaps given the strength of character he has displayed since we have come to know and work with him.
"We will do everything we can to support Paul and his family in this difficult period of their lives," he promised.