Uterine fibroid. Coloured pelvic X-ray of a 65 year old woman's calcified fibroid (fibromyoma, red, centre) in her uterus (womb). A fibroid is a benign tumour of fibrous and muscular tissue. Many women have small fibroids, and although most do not require treatment they can cause bleeding, pain and other gynaecological disorders. It can be treated with drugs to reduce its size, but large growths may require surgical removal.