Submucosal Fibroid

The submucosal fibroid (Latin sub — below, mucosa — mucous membrane) is a clinical anatomical variant of uterine leiomyoma, in which the mass grows centripetally (towards the uterine cavity), deforming its architecture.

Etiology and pathophysiology

According to the modern FIGO classification (PALM-COEIN), submucosal fibroids are divided into three types depending on their relationship with the myometrium:

• Type 0: The fibroid is completely within the uterine cavity (on a pedicle), not invading the myometrium.
• Type 1: Less than 50% of the fibroid’s volume is embedded into the uterine wall.
• Type 2: More than 50% of the fibroid’s volume is intramural (within the muscle thickness). The fibroid causes stretching of the uterine cavity, increasing the area of desquamation and local ischemia/ulceration of the overlaying endometrium.

Clinical significance

Submucosal localization is the most clinically aggressive. Even small fibroids (1–2 cm) cause profuse menorrhagia with clots, leading to severe therapy-resistant anemia. Cramp-like pains are characteristic (“birthing fibroid”).

Furthermore, submucosal fibroids act like intrauterine contraceptives: they cause chronic inflammation and mechanically obstruct implantation, serving as an absolute cause of uterine infertility. Treatment — hysteroscopic resection (removal via vaginal access).