By Ariane Sohrabi-Shiraz Celebrity Big Brother star Louis Walsh has opened up about battling a rare form of blood cancer, which around 350 in the UK are diagnosed with every year. The 71-year-old opened shared his diagnosis in a conversation with housemates Levi Roots and Ekin-Su Culculoglu on the ITV show. When asked how he dealt with the Covid lockdown, he replied: “I was sick, and I think nobody knew I was sick. I had cancer – a mild version, a rare one, in my blood. I didn’t even know I had it until I went to the hospital. They checked me and then they found it.” The former X Factor judge …