Four-year-old Aleisha Hunter is a member of a very small survivor's club: At age 2, she was stricken with breast cancer.

Her mother noticed a pea-sized lump on the left side of her daughter's chest and took her to doctors, who at first didn't know what was wrong. Aleisha, who lives in Ontario, Canada, was eventually diagnosed with juvenile breast carcinoma, an extremely rare form of breast cancer. As the lump grew, it became painful, and Aleisha had trouble eating and sleeping.

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On Thursday, Aleisha smiled and snuggled with her mother, Melanie, and her teddy bear, Bear, as Matt Lauer discussed her unusual case with Dr. Nancy Down, a cancer surgeon at North York General Hospital.

"Aleisha was in a fair bit of pain, because the tumor was stretching the tissue, so it actually came as somewhat of a relief in a sense because the pain was gone after her surgery," Dr. York said.

When Aleisha was 3, she had a radical modified mastectomy, which means doctors at North York General Hospital removed her entire nipple, areola, breast tissue and the lymph nodes under her left arm. During Aleisha's hospital stay, her mom — and her teddy bear — stayed at her side.

Aleisha's mom, Melanie, who works in a long-term care facility, told TODAY earlier that she's talking about her daughter's rare cancer to raise awareness about breast cancer, and also because of all the ill children she met during Aleisha's many hospital stays -- she says she wants to remind parents to hug their children and tell them they love them.

"She's extremely brave, she's extremely strong, and she's happy -- she's a bubbly little 4-year-old," Melanie Hunter told TODAY.

Now Aleisha is cancer-free, and doctors say her prognosis is good. Aleisha will eventually need reconstructive surgery, but for now, her biggest priority is preschool.