"Im showing you this picture because this is what melanoma looks like," Judge captioned a photo showing a small dark patch on her behind. "I don't want sympathy, I want you to save YOUR [expletive] and get your skin checked."
"This was just a small black flat freckle.... I had no idea! Ill be fine because my faith is strong and my [expletive] ain't bad either," she joked. "I've been a little sad, worried and [expletive] off. But we caught it early and that makes me happy. Happy birthday to me."
Judge's announcement came just days before she was supposed to celebrate her birthday Sept. 2 in Cabo San Lucas, Mexico. She confessed in the post that her trip was "not sounding like a good idea now."
Judge is mom to son Ryan with first husband Darren Vieth, and to son Spencer and daughters Sophia and Sidney with second husband Simon Barney.
She and husband Eddie Judge renewed their wedding vows in Aruba this month following their fourth anniversary in June.
"Celebrating love with all the hate that's going on," the star wrote Aug. 8. "May God bless your life because it's not always easy. But God has a plan.. a big plan."
Copyright 2017 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.