Endometriosis and adenomyosis

Diffuse adenomyosis, focal adenomyosis, ovarian endometrioma, superficial endometriosis and deep infiltrating adenomyosis are all defined by the presence of an endometrioid tissue in an ectopic location that is at distance from the endometrium. Although frequently associated, these lesions represent different clinico-pathological entities that the pathologist should recognized. Herein, we review the clinical and pathological features of these entities, as well as related current physiopathotogical understandings and differential diagnoses that could be raised by some morphological variants. The statistical association between endometriosis and several ovarian tumors, mainly endometrioid and clear cell carcinomas and seromucinous borderline tumors is well established and we present some molecular and morphological features that support this transformation potential. (C) 2021 Elsevier Masson SAS. All rights reserved.