Teddi Mellencamp Arroyave has unfortunate news for fans regarding her battle with melanomas.

"The Real Housewives of Beverly Hills" alumna shared on Instagram on Tuesday that immunotherapy treatment "did not work on my melanomas." In the photo she posted, Mellencamp, 42, has pink scars across her upper back and right shoulder blade.

She added: "I had a wide excision removal on my most recent melanoma last week to see if it did and sadly it did not."

According to the American Cancer Society website, immunotherapy is a "treatment that uses a person's own immune system to fight cancer. Immunotherapy can boost or change how the immune system works so it can find and attack cancer cells."

Mellencamp and her doctors, she wrote, decided that "the best next course of action" is to have surgery next week "to remove a larger portion of (the) problematic area."

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"I don’t like going under and my anxiety is popping off but I have faith all will be ok and that the reason this is happening to me is because I am able to raise awareness," she wrote.

"After surgery, when god willing my margins are clear, we will continue to monitor my body closely every 3 months," Mellencamp added. "In the meantime, I am so looking forward to spending Christmas with my loved ones and hope this is a reminder to book your skin checks for the new year."

Mellencamp has been open about her skin cancer journey.

She shared her Stage 2 melanoma diagnosis last year and wrote on Instagram, "Moral of this story: if a doctor says, 'come in every 3 months' please go in every 3 months. I so badly wanted to blow this off."

"I continue to share this journey because I was a 90s teen, putting baby oil and iodine on my skin to tan it. Never wearing sunscreen or getting my moles checked until I was 40 years old," she added. "This has been such a wakeup call for me, and I hope to all of you, to love and protect the skin you’re in."

What is melanoma?

Melanoma only accounts for around 1% of skin cancers but is more likely than other types of skin cancer to grow and spread, making it more dangerous. It "causes a large majority of skin cancer deaths," according to the American Cancer Society.

It occurs when "melanocytes (the cells that give the skin its tan or brown color) start to grow out of control." For people with lighter skin tones, melanomas are more likely to start on the legs for women and on the chest and back for men. Other common sites are the neck and face.

According to the American Academy of Dermatology, "When skin cancer develops in people of color, it’s often in a late stage when diagnosed." For Black people, "skin cancer often develops on parts of the body that get less sun like the bottom of the foot, lower leg, and palms."

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