 After two months of quietly dealing with his symptoms , Cullen 's wife finally called team trainers and asked them to check into his illness . The team took an x @-@ ray and found a large black shadow in his chest . He underwent a CAT scan which revealed Cullen had a baseball @-@ sized tumor ; he was diagnosed as having Non @-@ Hodgkin lymphoma . The diagnosis ended his season , and he immediately began chemotherapy treatments that quickly reduced his cancer . The tumor was gone by September 1997 , but a <unk> test prior to training camp revealed that Cullen still had cancer cells in his body . He missed the entire 1997 – 98 NHL season as he continued to battle the disease , while his teammates wore a uniform patch with his # 12 in support throughout the year . 
