PALM-COEIN subclassification system for leiomyomas

FIGO leiomyoma subclassification system. System 2 classification system including the FIGO leiomyoma subclassification system. The system that includes the tertiary classification of leiomyomas categorizes the submucous group according to the original Wamsteker et al system^[1] and adds categorizations for intramural, subserosal, and transmural lesions. Intracavitary lesions are attached to the endometrium by a narrow stalk (≤10% or the mean of three diameters of the leiomyoma) and are classified as Type 0, whereas Types 1 and 2 require a portion of the lesion to be intramural: with Type 1 being less than 50% of the mean diameter and Type 2 at least 50%. Type 3 lesions are totally intramural but also about the endometrium. Type 3 are formally distinguished from Type 2 with hysteroscopy using the lowest possible intrauterine pressure necessary to allow visualization. Type 4 lesions are intramural leiomyomas that are entirely within the myometrium, with no extension to the endometrial surface or to the serosa. Subserous (Types 5, 6, and 7) leiomyomas represent the mirror image of the submucous leiomyomas: with Type 5 being at least 50% intramural, Type 6 being less than 50% intramural, and Type 7 being attached to the serosa by a stalk that is also ≤10% or the mean of three diameters of the leiomyoma. Classification of lesions that are transmural are categorized by their relationship to both the endometrial and the serosal surfaces. The endometrial relationship is noted first, with the serosal relationship second (eg, Type 2-5). An additional category, Type 8, is reserved for leiomyomas that do not relate to the myometrium at all, and would include cervical lesions (demonstrated), those that exist in the round or broad ligaments without direct attachment to the uterus, and other so-called "parasitic" lesions.