Rebecca Hockaday noticed the spot on her breast toward the end of summer.

โ€œI thought, okay, a freckle on my chest. Iโ€™ve been out in the sun, no big deal,โ€ the Georgia mother of two remembered thinking.

But then a few more popped up, appearing as if the first one had spread. Several months later, Hockaday made an appointment with her dermatologist.

โ€œHonestly, I thought they were sun spots. I thought they were going to say, ‘just your skin aging,’โ€ she told TODAY. โ€œNever in a million years did I think, okay, this is going to be cancer.โ€

A biopsy revealed that Hockaday, who was 35 at the time, had inflammatory breast cancer, a rare and aggressive form of the disease. The cancer had already spread to her lymph nodes by the time it was diagnosed, she said.

Inflammatory breast cancer, or IBC, doesnโ€™t present itself like common forms of the disease, which is usually detected through a lump in the breast or a mammogram, said Dr. Jean Wright of the Johns Hopkins Breast Cancer Program.

โ€œHalf the time thereโ€™s no lump or anything like that. Itโ€™s just the kind of skin changes, and so it can relatively easily be mistaken for an infection, mastitis or something like that,โ€ she said.

Redness or swelling of the breast are the usual hallmark for IBC. Sometimes, the skin may appear somewhat dimpled like an orange peel.

IBC makes up less than 2 percent of all breast cancer, said Wright, an associate professor of radiation oncology at Johns Hopkins.

โ€œThe most characteristic thing is that it happens very quickly. Itโ€™s usually within one month you notice these significant changes in the skin of (the) breast,” she said.