Uterus

Nontumor

Adenomyosis / adenomyoma


Editorial Board Member: Ayse Ayhan, M.D., Ph.D.
Irem Onur, M.D.

Last author update: 1 October 2016
Last staff update: 20 February 2024

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PubMed Search: Uterine adenomyosis

Irem Onur, M.D.
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Cite this page: Onur I. Adenomyosis / adenomyoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/uterusadenomyosis.html. Accessed February 22nd, 2024.
Definition / general
  • A nonneoplastic lesion of myometrial tissue characterized by the presence of endometrial glands and stroma within myometrium (Best Pract Res Clin Obstet Gynaecol 2006;20:511)
  • Synonyms: myometrial endometriosis, superficial adenomyosis (1 - 2.5 mm in myometrium), stromal adenomyosis, incomplete adenomyosis, adenomyosis with sparse glands
  • Usually an incidental finding in hysterectomy specimens (Int J Gynecol Pathol 1996;15:217)
  • May be diffuse or focal
  • May be involved by hyperplasia and carcinoma
Terminology
  • Adenomyoma: A circumscribed nodular aggregate of benign endometrial glands surrounded by endometrial stroma, with leiomyomatous smooth muscle bordering the endometrial stromal component
ICD coding
  • ICD-10: N80.0 - endometriosis of uterus
Epidemiology
Sites
  • Frequently in posterior, less commonly in anterior uterine wall
  • Rarely in cornua or by cervical os
Pathophysiology
Etiology
  • Adenomyosis and endometriosis are usually regarded as closely related, but
    • Microscopic appearance, and probably their pathogenesis, are somewhat different
    • They may occur independently of each other
    • Adenomyosis mostly is made up of nonfunctional (basal) endometrium and is frequently connected with the mucosa (vs. endometriosis, composed of functional layers)
    • Adenomyosis may represents a unique form of endometrial diverticulosis
  • Hypothetical mechanisms include (Crum: Diagnostic Gynecologic and Obstetric Pathology, 2nd Edition, 2011)
    • Instillation of endometrium within the myometrium
    • In situ metaplasia of pluripotent stem cells retained in myometrium or
    • Improper partitioning of the endometrium from the myometrium
  • Of note, del(7) (q21.2q31.2), a deletion found in typical leiomyoma, has been found in three cases of adenomyosis, suggesting some pathobiologic overlap between leiomyomata and adenomyosis (Cancer Genet Cytogenet 1995;80:118)
  • Definitive distinction between these explanations requires further study
Clinical features
Diagnosis
  • By histopathologic examination of well oriented hysterectomies
  • Essentially should not be diagnosed in curettings or hysteroscopic material
Radiology description
Prognostic factors
  • Benign; excellent prognosis even if not removed
Case reports
Treatment
Gross description
Gross images

Contributed by Ayse Ayhan, M.D., Ph.D.
Pre and post-fixed uterus wall

Pre and post-fixed uterus wall

Cut surface of uterus

Cut surface of uterus



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Thickened and spongy myometrium

Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Ayse Ayhan, M.D., Ph.D.
Depth of penetration

Depth of penetration

Endomyometrial junction is irregular

Endomyometrial junction is irregular

Glandular tissue usually inactive

Glandular tissue usually inactive

Stroma poor and gland poor

Stroma poor and gland poor

Residual nonneoplastic endometrial glands

Residual nonneoplastic endometrial glands


Adenosarcoma arising in endometriosis

Adenosarcoma arising in endometriosis

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Various images

AE1 / AE3 and CD10

AE1 / AE3 and CD10



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Endometrial glands and stroma

Positive stains
Differential diagnosis
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