Shannen Doherty has been diagnosed with breast cancer.

Shannen Doherty has been diagnosed with breast cancer.

The former Beverly Hills: 90210 star is now likely to undergo chemotherapy and a mastectomy, according to court documents.

The 44-year-old US actress’ news was revealed following a lawsuit regarding her medical insurance, and Doherty later confirmed the diagnosis to PEOPLE magazine.

“Yes, I have breast cancer, and I am currently undergoing treatment,” she told PEOPLE.

“I am continuing to eat right, exercise and stay very positive about my life. I am thankful to my family, friends and doctors for their support and, of course, my fans who have stood by me.”

Doherty claims in her lawsuit that her accounting management firm failed to pay for her Screen Actors Guild medical insurance without her knowledge.

According to court documents obtained by E!, she alleges firm Tanner Mainstain kept a portion of her earnings normally used to pay her medical insurance. It then allegedly ignored an invoice for payment of the insurance premium, causing the Guild to cancel her insurance.

In March 2015, Doherty visited a doctor and learned of her diagnosis.

Doctors told her she had “invasive breast cancer metastatic to at least one lymph node,” and that her cancer likely spread last year while she was uninsured, according to E!.

Court documents reveal she is now likely to undergo a mastectomy and chemotherapy.

A spokesperson for the firm being sued has denied Doherty’s allegations, telling TMZ any claim that it “somehow contributed to her cancer is patently false.”

Doherty cut all ties with the management firm in February last year, according to court documents.

Doherty appeared as Brenda Walsh in Beverly Hills, 90210 for four years from 1990, a role that earned her a Young Artist Award nomination for Best Young Actress Starring in a Television Series.

She also played Prue Halliwell in Charmed from 1998 until 2001, after which she mainly focused on made-for-TV movies.

Doherty, who is married to photographer Kurt Iswarienko, is also an avid animal rights and environmental activist.

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