The mum-of-four took to Instagram to share a selfie - which included the cancerous 'freckle' on her bottom - with her 1.2million followers, and the candid snap quickly received over 31k likes and over 2k comments.
I work out ð hard for this Booty. I was planning on competing again in November at 50 years old, but I'm not sure that's happening ð© now. it looks like God has a different plan for me. Im showing you this picture because this is what melanoma looks like. I don't want sympathy, I want you to save YOUR ASS and get your skin checked . This was just a small black flat freckle.... I had no idea! Ill be fine because my faith is strong and my Ass ain't bad eitherð Thank you @cacoastalderm â¤ï¸. I've been a little sad , worried and pissed off. But we caught it early and that makes me happy ð Happy birthday to me. #saveyourass birthday party in Cabo not sounding like a good idea now ð¡ #awareness.#skincheck
Tamra is a self-confessed fitness fanatic and, at the age of 49, she was excited at the taking part in fitness competitions again.
However, the excitement was short lived after what she presumed was a harmless freckle turned out to be melanoma.
In the Instagram caption she said: 'It looks like God has a different plan for me. I'm showing you this picture because this is what melanoma looks like,' she wrote.
'I don't want sympathy, I want you to save YOUR ass and get your skin checked. 'This was just a small, black, flat freckle...I had no idea!'
While Tamra admitted that she is naturally 'a little sad, worried and pissed off', she is taking some comfort from the fact that her illness was caught early on.
The post was flooded with messages of support: 'Prayers for you. Lost my aunt at 54. Such an important message. People should have a yearly skin check,' wrote one fan.
'Melanoma spreads quickly and hits hard. Being proactive, as I see by all your biopsies, gives you the fighting chance in this disease,' replied another.
This isn't the first time Tamra has had to share such sad news. In January, Tamra shared a picture of herself after it was discovered she had basal cell skin cancer and one squamous cell skin cancer. She underwent surgery to remove the cancerous cells.
Tamra is not only a reality star she's also a devoted mum to four children: 31-year-old Ryan, 18-year-old Sidney, 16-year-old Spencer, and 11-year-old Sophia.