The macro-microscopic study of colonized endometriotic scar tissue showed that, besides being typically characterized as ectopic endometriosis with cyclic morphological and functional features, it might change into a benign pseudonodular tumor with commonly progressive patterns due to invasion and reproduction aspects, causing the growth of the primary endometriotic lesions. These changes characterize ectopic endometriosis and endometriotic tissues colonized as tumors, so called abenign ectopic scar endometrioma. The morphopathology used the term benign ectopic endometrioma within this study, characterized by the presence of typical endometrial-like tissue (gland with inactive epithelium, circumscribed by an insignificant cuff of endometriotic stromal vascular network) andtransformations of the glandular, glandularstromal and / or mixed structure through the cystic glandular component. This present research determined the following morphological features: (1) presence of active and inactive evolutionary forms; (2) presence of elastosis within the stroma and tissues; (3) unformed endometriotic globoid formations located remotely from the primary source, resembling endometriotic or stromal-glandular stromal loops, defined as endometriotic satellites; (4) mimicry of the morphological features characterictic for pseudoxandoma, pseudomixoma or fibroelastoma.