FIGO - Uterine Fibroids Classification
FIGO (International Federation of Gynecology and Obstetrics) classification system for uterine fibroids by anatomical location.
About the FIGO Classification
The FIGO (International Federation of Gynecology and Obstetrics) classification for uterine fibroids is the most widely used system worldwide to describe fibroid location in relation to the endometrium and myometrium, enabling standardized communication, guiding management, and predicting clinical impact.
It is based on numbers 0 to 8 (and combinations such as 2–5), dividing fibroids into submucosal, intramural, subserosal, and fibroids of special location.
Reference: Munro MG, Critchley HO, Broder MS, Fraser IS, for the FIGO Working Group on Menstrual Disorders. FIGO classification system (PALM-COEIN) for causes of abnormal uterine bleeding in nongravid women of reproductive age. International Journal of Gynaecology and Obstetrics. 2011;113(1):3-13. doi:10.1016/j.ijgo.2010.11.011.
FIGO Classification - All Fibroid Types
Color Legend
These three (FIGO 0, 1 and 2) are the ones that actually distort the uterine cavity
FIGO Categories
FIGO 0
Pedunculated intracavitary fibroid.
No intramyometrial component.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid located entirely within the endometrial cavity, without intramyometrial component, connected to the myometrium by a thin pedicle.
FIGO 1
Less than 50% of the volume is within the myometrium.
Most protrudes into the cavity.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid that projects predominantly into the endometrial cavity, with less than 50% of the nodule located within the myometrium, which may cause cavity distortion.
FIGO 2
≥ 50% of the fibroid is intramyometrial, but still projects into the cavity.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid with 50% or more of the nodule located within the myometrium, with partial projection into the endometrial cavity, producing indentation or asymmetry of the cavity.
FIGO 3
Contacts the endometrium, but does not distort the cavity.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid entirely located within the myometrium, in contact with the endometrium, but without protrusion into the cavity.
FIGO 4
Entirely intramural, with no contact with endometrium or serosa.
These are "pure" intramural fibroids.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid with 100% of the nodule located within the myometrium, without contact with the endometrium or serosa.
FIGO 5
≥ 50% intramyometrial, but with subserosal projection.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid with 50% or more of the nodule located within the myometrium, with subserosal projection, causing bulging of the uterine surface.
FIGO 6
< 50% intramyometrial and predominantly subserosal.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid with less than 50% of the nodule located within the myometrium, predominantly as subserosal projection, attached to the uterus by a broad base.
FIGO 7
Pedunculated subserosal, entirely outside the serosa.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid entirely external to the uterine contour, without intramyometrial component, attached to the serosa by a pedicle.
FIGO 8
Fibroids in atypical locations, outside the typical corporal topography of the uterus.
📋Recommended US report description:
Myometrial nodular formation compatible with fibroid located in the cervix, with well-defined contours and typical morphology, without relation to the uterine body. Myometrial nodular formation compatible with fibroid located in the broad ligament topography, with recognizable plane of separation from the uterus and morphology compatible with broad ligament fibroid. Myometrial nodular formation compatible with fibroid located outside the uterine contour, with appearance suggestive of adherence to adjacent pelvic structures, maintaining typical fibroid morphology. Detailed description of apparently involved pelvic structures may be added according to individual ultrasonographic assessment of each case.
FIGO 2-5
Fibroid that completely traverses the myometrium, with submucosal (2) and subserosal (5) components.
Occupies two anatomical interfaces simultaneously, which may cause more intense symptoms and greater surgical complexity.
📋Recommended US report description:
Myomatous nodule that completely traverses the myometrium, with simultaneous submucosal and subserosal components. Endometrial cavity distortion and uterine surface bulging are observed. Detailed description depends on the case.