Classification of Uterine Adenomyosis

Purpose of Review The purpose of the present study is to review the existing literature regarding the classifications of uterine adenomyosis and to assess the clinical significance of each classification. Recent Findings Adenomyosis is a benign gynecological disease characterized by the presence of ectopic endometrial tissue (glands and stroma) within the myometrium surrounded by hyperplastic and hypertrophic smooth musculature within the uterus. There are several classifications of uterine adenomyosis. The disease is mainly classified in focal adenomyosis, diffuse adenomyosis, and adenomyomas. The histopathologic classification recognizes 4 criteria: the distance of the foci from the endometrium, the depth of the penetration, the pattern of the disease, and the configuration of the lesion. The sonographic classification includes as criteria the abnormalities in (a) the uterine serosa, (b) the definition of the lesion, (c) the symmetry of the uterine walls, (d) the shape, (e) the contour, (f) the shadowing of the lesion, (g) the echogenicity, (h) the vascularity of adenomyosis, and the (i) regularity of the endometrial rim. The MRI classification uses as criteria (a) the presence of disease in the inner uterine layer, (b) the presence of disease in the outer uterine layer, and (c) the solidarity of the lesions. Finally, the clinical, treatment-based classification uses as criteria the extent of the presence of the disease throughout the myometrium, the configuration of the lesion (focal or diffuse), and the consistency of the lesion (cystic/solid, and gland- or muscle-predominant). Summary There are numerous proposed classifications of uterine adenomyosis, mainly based on histopathological and imaging findings. The current emerging challenge is the integration of the pathogenesis, the clinical phenotype, the imaging features, and the histology of the disease, in a common classification that will allow an accurate treatment decision and further satisfactory prognosis of the adenomyotic lesion in all the affected patients.