Ovary
Mucinous tumors
Mucinous borderline tumor / atypical proliferative mucinous tumor


Topic Completed: 1 July 2012

Minor changes: 6 April 2020

Copyright: 2003-2020, PathologyOutlines.com, Inc.

PubMed Search: Ovarian mucinous borderline tumor

Page views in 2019: 13,881
Page views in 2020 to date: 13,028
Cite this page: Ehdaivand S. Mucinous borderline tumor / atypical proliferative mucinous tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/ovarytumorborderlinemucinous.html. Accessed September 29th, 2020.
Definition / general
  • Also called atypical proliferative mucinous tumor of ovary or mucinous ovarian tumor of low malignant potential
  • 85% are intestinal type; 15% are seromucinous (endocervical) type
  • 5% of intestinal type are bilateral; 30 - 40% of seromucinous type are bilateral (Cancer 1988;61:340)
  • Pure borderline tumors and borderline tumors with intraepithelial carcinoma or microinvasion are almost always Stage I and clinically benign, but must sample tumor extensively to rule out more extensive invasion (Am J Surg Pathol 2002;26:139)
  • High stage borderline tumors with abdominal cavity mucin may represent ovarian metastases rather than primary borderline tumors - must examine appendix to correctly interpret
Clinical features
Intestinal type:
  • 85% of borderline mucinous cases
  • Older patients, not associated with endometriosis
  • Excellent prognosis
  • Intestinal type are further divided:
    • With atypia only
    • With intraepithelial carcinoma
    • With microinvasion

Seromucinous (endocervical) type:
  • 15% of borderline mucinous tumors
  • Tumors usually mixed but clinically resemble serous tumors due to papillary architecture, serous type differentiation, frequent bilaterality, smaller size, indolent clinical behavior (only rare deaths, Am J Surg Pathol 2002;26:1529)
  • Mean 39 years (younger patients), range 25 - 64 years
  • Associated with endometriosis in 41% of cases, endosalpingiosis in 32%
  • Malignancy is based on cytology, not number of cell layers
  • Almost always stage I, excellent prognosis with no evidence of disease at followup, even with intraepithelial carcinoma, microinvasion or extraovarian involvement (implants and lymph node involvement) (Am J Surg Pathol 2004;28:1311)
Prognostic factors
  • 10 year survival: stage I - 95% (better than previously thought; prior series may have included metastases from intestine and pancreas); noninvasive malignant - 90% (Am J Surg Pathol 2000;24:1447)
Gross images

AFIP images

Intestinal type

Mucinous cystic tumor



Images hosted on other servers:

Intestinal type

Seromucinous borderline tumor

Microscopic (histologic) description
  • Intestinal type:
    • With atypia only:
      • Resemble dysplastic intestinal epithelium with goblet cells, neuroendocrine cells and occasional Paneth cells
      • Neoplastic cells have hyperchromasia, crowding, increased mitosis, and stratification forming papillae with thin fibrous cores
      • Lumens contain mucin
    • With intraepithelial carcinoma:
      • Resemble high grade dysplasia of intestines with severe cytologic atypia without stroma invasion
      • Papillae without stroma and cribriforming is often present
    • With microinvasion:
      • Invasive foci measuring less than 10 mm2 and < 3 mm in greatest dimension
      • Foci of stromal invasion with desmoplastic response or small clusters of cells, occasionally cribriform with eosinophilic cytoplasm with minimal / absent stromal reaction (Hum Pathol 1996;27:521)
      • Desmoplastic stroma has pale nuclear staining, fibrous reaction or edema in stroma
      • Areas of mucin extravasation with inflammatory response are not diagnostic of invasion; this includes a brisk inflammatory reaction with histocytes and large areas of necrosis

  • Seromucinous (endocervical) type:
    • Proliferation of branching papillary structures resembling borderline serous tumors
    • Papillae composed of fibrovascular cores of variable size covered by variable epithelium including mucinous or eosinophilic cells
    • Mucinous cells have basal nuclei
    • Some papillary tips lack fibrovascular cores
    • Small detached clusters of cells may be observed over the papillary tufts
    • Hobnail cells also present
    • Rare intraepithelial carcinoma or stromal microinvasion but no stromal invasion
    • Associated with invasive or noninvasive desmoplastic implants

  • Classification:
    1. Borderline with atypia: grade 1 nuclei and papillae with cords
    2. Borderline with intraepithelial carcinoma: grade 2/3 nuclei, 4+ layers or cribriform or stroma-free papillary growth pattern
    3. Borderline with microinvasion: invasive glands usually accompanied by desmoplastic reaction
Microscopic (histologic) images

AFIP images

Mucinous cystic tumor with intraepithelial carcinoma



Intestinal type

Mucinous cystic tumor



Seromucinous (endocervical) type

Mucinous cystic tumor

Mixed epithelial types

Omental implant

Molecular / cytogenetics description
Back to top
Image 01 Image 02