Calcified uterine fibroid. Coloured frontal X-ray of a woman's pelvis, showing a calcified fibroid (yellow, upper centre) growing in the uterus. A fibroid is a benign (non-cancerous) tumour originating from muscular tissue. Most do not require treatment, but calcified fibroids can be particularly painful. Fibroids can also cause bleeding and other disorders. Large fibroids may need to be surgically removed.