Uterine fibroid. Coloured urogram (X-ray) of the pelvis of a patient with a large calcified uterine fibroid (red and orange). The bladder (white), at lower centre left, is being compressed by the fibroid. A fibroid is a fibrous benign tumour originating from muscular tissue. Most do not require treatment, but some can cause bleeding, pain and other disorders. Large fibroids may need to be surgically removed.