Uterine fibroid. Coloured frontal hysterogram (X- ray) of a woman's uterus (womb, white, centre) showing a fibroid (blue mass) growing on the internal wall. 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. The cervical isthmus, the upper portion of the cervix (neck of the womb), also shows elongation. A hysterogram uses a radio-opaque contrast medium to show the uterus on an X-ray.