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Monday 15 March 2004


Definition : Presence of endometrial tissue outside of endometrium and myometrium, consisting of both endometrial glands and endometrial stroma.


- colorectal endomatriosis

- vesical endometriosis

- Nodule at site of previous Pfannenstiel incision , associated with cyclical pain.

- CD10 in endometriosis


- genital endometriosis

- pulmonary endometriosis
- subcutaneous endometriosis
- vesical endometriosis
- parietal endometriosis


At least 2 of the following 3 features :
- Endometrial type glands:

  • Müllerian type epithelium (can be atrophic to cycling endometrium)
  • Can show degenerative atypia (enlarged smudgy nuclei) or metaplasia

- Endometrial type stroma:

  • Often contains fine capillary network
  • May undergo smooth muscle metaplasia, fibrosis (longstanding), decidual change
  • May be myxoid (particularly in pregnancy)
  • Stroma may be only identifiable component (stromal endometriosis)
  • Evidence of chronic hemorrhage (hemosiderin laden or foamy macrophages)

- Other rare findings:

  • Necrotic pseudoxanthomatous nodules: central necrosis surrounded by histiocytes and outer fibrous zone
  • Liesegang rings: eosinophilic acellular rings within necrotic tissue (Histopathology 2020;76:76)
  • Burnt out endometriosis: this term has been proposed for changes suggestive of endometriosis, such as central necrosis with surrounding fibrosis and pseudoxanthoma cells but lacking confirmatory features as listed above

Atypical endometriosis

- this has been reported in 1.7 - 4.4% of endometriotic lesions
- is considered the precursor lesion for endometriosis associated carcinomas (clear cell or endometrioid); may be in continuity with these tumors
- Includes cytologic atypia in the epithelial lining of the glands or gland crowding lined by atypical epithelium resembling endometrial atypical hyperplasia (Histopathology 1997;30:249, Case Rep Oncol 2013;6:480)“”


- CD10 expression by endometrial stroma in endometriosis

Digital case

- JRC:6314 : pulmonary.

Predisposition loci

- 10q26


- endometriosis-associated malignancies (EAM)


- Survivin, MMP-2, MT1-MMP, and TIMP-2: their impact on survival, implantation, and proliferation of endometriotic tissues. Londero AP, Calcagno A, Grassi T, Marzinotto S, Orsaria M, Beltrami CA, Marchesoni D, Mariuzzi L. Virchows Arch. 2012 Sep 6. PMID: 23011643

- Matarese G, De Placido G, Nikas Y, Alviggi C. Pathogenesis of endometriosis: natural immunity dysfunction or autoimmune disease? Trends Mol Med. 2003 May;9(5):223-8. PMID: 12763528