Ovary

Mucinous tumors

Mucinous cystadenoma / adenofibroma

Author: Gulisa Turashvili, M.D., Ph.D.

Editorial Board Member: C. Blake Gilks, M.D.

Deputy Editor-in-Chief: Jennifer A. Bennett, M.D.

Topic Completed: 28 September 2021

Minor changes: 28 September 2021

Copyright: 2003-2022, PathologyOutlines.com, Inc.

PubMed Search: Mucinous cystadenoma[TI] OR mucinous adenofibroma[TI] ovary[TIAB] full text[SB]

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Table of Contents

Cite this page: Turashvili G. Mucinous cystadenoma / adenofibroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ovarytumormucinousbenign.html. Accessed January 21st, 2022.

Definition / general

Benign mucinous neoplasm composed of cysts and glands lined by gastrointestinal or Müllerian type mucinous epithelium lacking architectural complexity or cytologic atypia

Essential features

Includes cystadenoma and adenofibroma
Usually unilateral and composed of variable amounts of cysts and glands lined by bland gastrointestinal or Müllerian type mucinous epithelium and variably cellular stroma
May be associated with mature teratoma or Brenner tumor
Excellent prognosis, with rare recurrences associated with cystectomy or rupture

ICD coding

ICD-O:
- 8470/0 - mucinous cystadenoma, NOS
- 9015/0 - mucinous adenofibroma, NOS
ICD-11:
- 2F32.Y & XH6H73 - other specified benign neoplasm of ovary and mucinous cystadenoma, NOS
- 2F32.Y & XH59X8 - other specified benign neoplasm of ovary and mucinous adenofibroma, NOS

Epidemiology

Accounts for 80% of primary ovarian mucinous neoplasms
Mucinous cystadenoma > adenofibroma (Int J Gynecol Pathol 2005;24:4, Cancer 1985;55:1958)
Median age 50 years (range 13 - 79) (Cancer 1985;55:1958)

Sites

Usually ovary
Less commonly, retroperitoneum (Int J Surg Case Rep 2012;3:486)

Pathophysiology

May arise from mature teratoma (possible germ cell origin) or Brenner tumor (Arch Pathol Lab Med 2008;132:1753)
KRAS mutations in 68% of cases (Cancer 1997;79:1581)

Etiology

Unknown

Clinical features

Abdominal distention with or without palpable mass
Abdominal or pelvic pain
Other symptoms related to abdominal / pelvic mass
Rarely, estrogenic or androgenic manifestations secondary to stromal luteinization (Int J Gynecol Pathol 2005;24:4)

Diagnosis

Microscopic examination

Laboratory

Rarely, elevated CA-125 (Cancer 1985;55:1958)

Radiology description

Ultrasonography:
- Usually large multilocular cystic adnexal mass with numerous thin septations
- Various degrees of echogenicity in different locules
- Low level internal echogenicity due to increased mucin content
Magnetic resonance imaging:
- Usually large multilocular cyst containing fluid of various viscosity resulting in variable signal intensities on both T1 and T2 sequences (stained glass appearance)
Reference: Radiographics 2000;20:1445, Radiographics 2019;39:982

Radiology images

Images hosted on other servers:

Palpable lower abdominal mass

Right pelvic pain

Prognostic factors

Excellent prognosis
Recurrences may occur after cystectomy or rupture and spillage (J Obstet Gynaecol Res 2006;32:615, Am J Obstet Gynecol 2010;202:142.e1)

Case reports

13 year old girl with recurrent ovarian mucinous cystadenoma after cystectomy (Int J Surg Case Rep 2021;83:106006)
22 year old woman with metachronous ipsilateral recurrent ovarian mucinous cystadenoma in initial pregnancy and mature teratoma in subsequent pregnancy (Cureus 2019;11:e3818)
40 year old woman with an ovarian mixed Brenner tumor and mucinous cystadenoma (J Clin Imaging Sci 2020;10:22)
71 year old woman with postmenopausal hyperandrogenism associated with ovarian mucinous cystadenoma (BMJ Case Rep 2021;14:e237505)

Treatment

Oophorectomy or cystectomy

Gross description

Usually unilateral (95%)
Smooth or bosselated surface
Cystadenoma:
- Uni or multilocular cyst with variably sized smooth walled locules
- Filled with dense, viscous, sticky, gelatinous material
- No solid areas or papillary excrescences
- Mean size 10 cm, rarely > 30 cm
Adenofibroma:
- Usually smaller
- Predominantly white and solid with variable amounts of small cysts (Int J Gynecol Pathol 2005;24:4, Surg Pathol Clin 2019;12:565)

Gross images

AFIP images

Mucinous cystadenoma

Associated with dermoid cyst

Frozen section description

Benign cystic neoplasm lined by a single layer of bland mucinous epithelium (cystadenoma) or solid and cystic neoplasm composed of small glands or cysts lined by a single layer of bland mucinous epithelium set in a fibromatous stroma (adenofibroma)

Frozen section images

Contributed by Gulisa Turashvili, M.D., Ph.D.

Unilocular cyst

Bland mucinous epithelium

Microscopic (histologic) description

Mucinous cystadenoma:
- Uni or multilocular cystic neoplasm composed of multiple cysts and glands lined by a single layer of bland mucinous epithelium
Mucinous adenofibroma:
- Solid and cystic neoplasm composed of small cysts or glands lined by a single layer of bland mucinous epithelium
- Stroma is fibromatous and variably cellular with or without luteinization
- Focal extravasated mucin or mucin granulomas with numerous histiocytes may be present secondary to cyst / gland rupture
General features:
- Simple nonstratified mucinous epithelium resembling Müllerian, intestinal or gastric foveolar type epithelium
- > 80% are intestinal type containing goblet cells
- Epithelium may be undulating but usually no epithelial stratification or tufting
- Columnar, cuboidal to flat nonciliated cells
- Variable amounts of mucinous cytoplasm
- Small basally located nuclei lacking cytological atypia
- Absent or minimal mitotic activity and apoptotic bodies
- Spiculated calcifications (62.5%) (Arch Pathol Lab Med 2008;132:1753)
Rare features:
- Tubular crypt-like outpouchings or papillary infoldings at the periphery of cysts
- Focal mild cytologic atypia and mitoses
- Goblet cells with or without neuroendocrine cells or Paneth cells
- Periglandular stromal condensation and luteinization (more common in pregnancy) (40%) (Arch Pathol Lab Med 2008;132:1753)
- Sex cord-like differentiation
- Necrosis (12.5%) (Arch Pathol Lab Med 2008;132:1753)
- Pseudoxanthoma cells (47.5%) (Arch Pathol Lab Med 2008;132:1753)
- Muciphages (42.5%) (Arch Pathol Lab Med 2008;132:1753)
- Pseudomyxoma ovarii (stromal dissecting mucin) and giant cell reaction (10%) (Arch Pathol Lab Med 2008;132:1753)
May be associated with:

Microscopic (histologic) images

Contributed by Gulisa Turashvili, M.D., Ph.D. and AFIP images

Unilocular cyst

Bland mucinous epithelium

Mucinous adenofibroma

Mucinous cystic tumor

Virtual slides

Images hosted on other servers:

Mucinous cystic neoplasm

Mucinous cystadenoma associated with Brenner tumor

Mucinous cystadenoma with functioning stroma

Mucinous cystadenoma, intestinal type

PAX8

CK7

CK20

Cytology description

Usually negative cytology or reactive mesothelial cells

Positive stains

CK7 (Am J Clin Pathol 2002;117:944)
PAX8: variable, may be focal
CK20: variable (Am J Clin Pathol 2002;117:944)
CDX2: variable

Negative stains

Molecular / cytogenetics description

KRAS mutations in 68% of cases (Cancer 1997;79:1581)

Sample pathology report

Right fallopian tube and ovary, salpingo-oophorectomy:
- Ovary: mucinous cystadenoma
- Fallopian tube: benign

Differential diagnosis

Mucinous tumor with focal atypia / proliferation (Hum Pathol 2004;35:949, Hum Pathol 2004;35:918, Am J Surg Pathol 1991;15:227):
- Focal (< 10%) architectural complexity, including papillae and tufting or nuclear pseudostratification and crowding
Mucinous borderline tumor:
- Architectural complexity with variable degrees of epithelial stratification, tufting and villous or slender filiform papillae in at least 10% of tumor
Metastatic low grade appendiceal mucinous neoplasm:
- Mucin on ovarian and extraovarian surfaces (pseudomyxoma peritonei)
- Bilateral ovarian involvement
- Detachment of mucinous epithelium from stroma (cleft-like space)
- Hypermucinous (highly differentiated, tall, mucin rich) cells
- Positive for CK20, CDX2 and SATB2; negative for PAX8, usually negative for CK7
Metastatic adenocarcinoma:
- Variable differentiation with high grade nuclear atypia and mitotic activity (gastrointestinal and pancreatico-hepatobiliary tract)
- Nuclear pseudostratification, apical mitoses and apoptotic bodies (human papillomavirus associated endocervical adenocarcinoma)
- Often bilateral, multinodular, with surface involvement, at least focal infiltrative growth and lack of correlation between architecture and cytology (Anticancer Res 2018;38:5465)

Board review style question #1

Which immunohistochemical markers are useful for differentiating this primary ovarian tumor from a low grade appendiceal mucinous neoplasm involving the ovary?

CK7, CK20, CDX2, SATB2 and PAX8
CK7, CK20, CDX2, WT1 and SATB2
CK7, CK20, PAX8, ER and SATB2
CK7, CK20, SATB2, ER and PR
CK7, CK20, SATB2, WT1 and PAX8

Board review style answer #1

A. CK7, CK20, CDX2, SATB2 and PAX8. Low grade appendiceal mucinous neoplasm is usually positive for CK20, CDX2 and SATB2 and negative for CK7 and PAX8.

Comment Here

Reference: Mucinous cystadenoma / adenofibroma

Board review style question #2

Which of the following is true for ovarian mucinous cystadenoma?

Always positive for PAX8
May be associated with mature teratoma or Brenner tumor
Most common in postmenopausal women
Usually bilateral ovarian involvement
Usually positive for ER and PR

Board review style answer #2

B. May be associated with mature teratoma or Brenner tumor

Comment Here

Reference: Mucinous cystadenoma / adenofibroma