<P> Speculation resumed , however , when Dean Morgan returned to the show for a second time in its fifth season . Cast member James Pickens , Jr. announced that both Heigl and T.R. Knight were set to depart from the show , but he later retracted his comment . During the course of the fifth season , Izzie was diagnosed with metastatic melanoma ( Stage IV ) which spread to her liver , skin and brain . Following the show 's one - hundredth episode wrap party , Heigl revealed she did not know if Izzie would survive , as no one on the production team would disclose her character 's fate to her . It was confirmed in June 2009 that Heigl would return as Izzie for the show 's sixth season . Heigl 's appearances in the season were sporadic , seeing Izzie depart and return twice . Although she was scheduled to appear in the final five episodes of the season , Heigl requested that she be released from her contract 18 months early , and made her final appearance on January 21 , 2010 . Heigl explained that she wanted to spend more time with her family , and did not think it would be respectful to Grey 's Anatomy viewers to have Izzie return and depart yet again . Michael Ausiello spoke further on Katherine Heigl 's perspective on Izzie 's departure . He said , `` ( Katherine ) thinks her Jan. 21 farewell - while not originally intended to be her last episode - oddly works as a bookend to Izzie 's story . `` Even though there 's a part of me that would like to go back and do the quick Izzie farewell , '' she says , `` I also think that my last scene - where Meredith says to Izzie , ' Do n't go , we 're your family , ' and Izzie 's response was , ' No you 're not , you 're just a bunch of people I worked with , and I can find that anywhere ' - was kind of tragic and appropriate all at the same time . When I was playing the scene I was really trying to convey that , for Izzie , that was a lie that she had to tell herself to have the courage to have to move on . '' </P>
<P> Speculation resumed , however , when Dean Morgan returned to the show for a second time in its fifth season . Cast member James Pickens , Jr. announced that both Heigl and T.R. Knight were set to depart from the show , but he later retracted his comment . During the course of the fifth season , Izzie was diagnosed with metastatic melanoma ( Stage IV ) which spread to her liver , skin and brain . Following the show 's one - hundredth episode wrap party , Heigl revealed she did not know if Izzie would survive , as no one on the production team would disclose her character 's fate to her . It was confirmed in June 2009 that Heigl would return as Izzie for the show 's sixth season . Heigl 's appearances in the season were sporadic , seeing Izzie depart and return twice . Although she was scheduled to appear in the final five episodes of the season , Heigl requested that she be released from her contract 18 months early , and made her final appearance on January 21 , 2010 . Heigl explained that she wanted to spend more time with her family , and did not think it would be respectful to Grey 's Anatomy viewers to have Izzie return and depart yet again . Michael Ausiello spoke further on Katherine Heigl 's perspective on Izzie 's departure . He said , `` ( Katherine ) thinks her Jan. 21 farewell - while not originally intended to be her last episode - oddly works as a bookend to Izzie 's story . `` Even though there 's a part of me that would like to go back and do the quick Izzie farewell , '' she says , `` I also think that my last scene - where Meredith says to Izzie , ' Do n't go , we 're your family , ' and Izzie 's response was , ' No you 're not , you 're just a bunch of people I worked with , and I can find that anywhere ' - was kind of tragic and appropriate all at the same time . When I was playing the scene I was really trying to convey that , for Izzie , that was a lie that she had to tell herself to have the courage to have to move on . '' </P>
when does izzy find out she has cancer
when does izzy find out she has cancer
During the course of the fifth season
During the course of the fifth season