Relationship between magnetic resonance imaging‐based classification of adenomyosis and disease severity

Aims The purpose of this study is to first investigate the correlation between image features and histological findings and the clinical severity of adenomyosis; second, search for imaging features to assess the type and locoregional extension of the disease; and finally, discuss the notation of image‐based classification. Methods This paper combines a review of the literature on adenomyosis with a series of cases who underwent surgery at Nara Medical University Hospital. Results Currently, there has been a lack of clear, clinically relevant, and internationally acceptable definition and histological classification due to its diverse phenotype. A number of researchers have attempted to standardize the magnetic resonance imaging (MRI) features of adenomyosis. Some researchers have begun studies that relate the subtype classification using MRI to disease severity. There is evidence suggesting that diffuse adenomyosis and intrinsic adenomyosis are correlated with menstrual bleeding, while extrinsic adenomyosis and coexistence of deep infiltrating endometriosis (DIE) are related to pelvic pain. MRI‐based classifications that are simple for use in the clinical setting are beginning to be proposed. However, the reliability and validity of these classifications have not yet been verified. A simplified notation is required to discuss the association between the classification and severity of adenomyosis. We introduce case reports using the notation of four items necessary for classification of adenomyosis. Conclusion There is an urgent need to determine the definitions of terms used in subtype classification and to create and validate a globally unified notation that can predict the severity of adenomyosis symptoms.