Leiomyomas is one of the common diseases in women of child-bearing ages, which are usually originate from the uterus. The incidence of broad ligament hysteromyoma is < 1%, and the giant broad ligament hysteromyoma is rare in clinic. The diagnosis is often confused with ovarian tumors and retroperitoneal tumors due to the degeneration. The patient had a special history of rectal cancer, which made it more difficult to diagnosis. Surgery was considerable difficult due to the large size. The authors also found the external iliac vein formed vascular diverticulum due to compression, which is uncommon to see in the clinic.