Subserosal Fibroid Becoming Parasitic in Pregnancy: A Rare Case Report

Uterine leiomyomas, commonly known as fibroids, are the most frequently encountered pelvic tumors in women, and the vast majority are benign. They originate from the smooth muscle layer of the uterus, known as the myometrium. The International Federation of Gynecology and Obstetrics (FIGO) has developed a classification system that divides fibroids into eight distinct types based on their location within the uterus. Parasitic fibroids are a rare entity, comes under category 8. A parasitic leiomyoma is a rare form of extrauterine fibroid that appears as a benign smooth muscle mass located separately from the uterus. In some cases, a pedunculated subserosal fibroid can detach entirely from the uterus and reattach itself elsewhere in the abdominal cavity, developing a new blood supply from nearby vessels. This condition is sometimes linked to prior surgical procedures, particularly laparoscopic interventions involving morcellation of fibroids. The definitive treatment for a parasitic fibroid is complete surgical removal (myomectomy). However, due to its atypical location, diagnosing such fibroids can be challenging. Here, we present a rare case of a subserosal fibroid located at the uterine fundus, which was in the process of becoming parasitic. During surgery, it was discovered that the fibroid had started deriving its blood supply from the omentum.