Ovary tumor
Endometrioid tumors
Endometrioid borderline tumor

Authors: Shahrzad Ehdaivand, M.D. (see Authors page)

Revised: 20 May 2016, last major update December 2012

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed search: Ovarian endometrioid borderline tumor
Definition / General
  • Rare (< 200 cases reported)
  • Mean age 55 years, range 28-86 years
  • 97% present with stage I disease
  • 36% associated with endometriosis
  • Typically no recurrent disease or metastasis on follow-up, even if intraepithelial carcinoma or microinvasion (Am J Surg Pathol 2003;27:1253, Am J Surg Pathol 2000;24:1465)
Micro Description
  • Composed of aggregates, glands or cysts of endometrioid-type epithelium that is atypical or cytologically malignant
  • May have architectural atypia including non-branching villous papillae, cribriform glands but lacks destructive stromal invasion, glandular confluence or stromal disappearance
  • Often has adenofibromatous pattern (47%) or squamous differentiation (47%)
  • May have foci of intraepithelial carcinoma (7%, high grade / grade 3 nuclei are large, pleomorphic with coarse chromatin or hypochromasia, large irregular nucleoli; also many mitotic figures; associated with villoglandular architecture or microinvasion)
  • Microinvasion if areas of invasion are 10 mm2 or less (7%)
Micro Images

Images hosted on PathOut server:

With intraepithelial carcinoma, grade 1

Atypical endometrioid glands separated by stroma



Images hosted on other servers:

Various images

Differential Diagnosis
  • Atypical endometriosis: will have endometrial stroma