Getty

Nicole Eggert says she underwent a major surgery this past weekend ... sharing a photo from after her mastectomy.

The actress shared a pic Wednesday in which she's wearing just a sports bra and a small pair of underwear ... no smile on her face. Instagram / @_nicole_eggert

She captioned the photo, "Had a mastectomy with reconstruction on Thursday. How was ur weekend?" -- so, she's putting on a pretty calm front despite the recent surgery.

Nicole revealed in early 2024 that she was going through cancer ... after which numerous celebrities sent money to support her during the difficult time. Play video content

She's provided updates on her cancer battle over the last couple years ... including letting fans know that she had a "full complete response" to chemotherapy last

See Full Page