Ovary
Endometrioid tumors
Endometrioid cystadenoma and adenofibroma
Author: Stephanie L. Skala, M.D.
Editorial Board Member: Gulisa Turashvili, M.D., Ph.D.
Deputy Editor-in-Chief: Jennifer A. Bennett, M.D.
Last author update: 3 August 2022
Last staff update: 24 December 2022
Copyright: 2003-2025, PathologyOutlines.com, Inc.
PubMed Search: Ovary endometrioid cystadenoma / adenofibroma
Table of Contents
Definition / general | Essential features | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Radiology description | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Virtual slides | Cytology description | Positive stains | Negative stains | Sample pathology report | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Skala SL. Endometrioid cystadenoma and adenofibroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ovarytumorendometadenofibroma.html. Accessed January 12th, 2025.
Definition / general
- Benign tumors with endometrioid type glands, sometimes associated with endometriosis
Essential features
- Benign biphasic tumor with endometrioid type glands and fibromatous stroma
- Sometimes associated with endometriosis
- Squamous or mucinous metaplasia or dystrophic stromal calcifications can be seen
ICD coding
- ICD-O:
- ICD-11:
- 2F32.Y & XH1CX5 - other specified benign neoplasm of ovary & endometrioid adenofibroma, NOS
Epidemiology
- Uncommon tumors, most often seen in postmenopausal women (Int J Gynecol Pathol 2000;19:276)
Sites
- Ovary
Pathophysiology
- In some cases, endometrioid cystadenomas may represent endometriotic cysts without obvious endometrial type stroma
Etiology
- Unknown
Clinical features
- Can be an incidental finding
- Symptoms may include abnormal vaginal bleeding, abdominal pain or pelvic mass (J Obstet Gynaecol 2011;31:352)
Diagnosis
- Detected on pelvic imaging (ultrasound, CT, MRI)
- Cystectomy / oophorectomy
Radiology description
- Low T2 weighted signal intensity of solid components (Radiographics 2021;41:289)
Prognostic factors
- These tumors are benign
Case reports
- 46 year old woman with pelvic pain, postmenopausal bleeding and 6.3 cm complex solid and cystic right adnexal mass (J Obstet Gynaecol 2011;31:352)
- 60 year old woman with vaginal bleeding and 14 cm pelvic mass (Diagn Cytopathol 2004;31:38)
- 64 year old woman with solid pelvic tumor (J Obstet Gynaecol Res 1998;24:161)
Treatment
- Not applicable; these tumors are benign
Gross description
- Cystadenoma: usually unilocular cyst
- Adenofibroma: firm, white nodule with honeycomb appearance to cut surface, sometimes in the wall of an endometriotic cyst (J Obstet Gynaecol 2011;31:352)
Gross images
AFIP images
With endometriosis
Microscopic (histologic) description
- Cystadenoma:
- Cyst lined by benign endometrioid epithelium without endometrial stroma
- Endometriosis may be present
- Adenofibroma:
- Widely spaced benign endometrioid glands associated with fibromatous stroma
- Endometriosis may be present
- Areas of mucinous or serous differentiation can be seen (Histopathology 2021;78:445)
Microscopic (histologic) images
Contributed by Stephanie L. Skala, M.D.
Variably dilated endometrioid glands
Endometrioid glands, some ciliated
Predominantly cystic neoplasm
Attenuated cyst lining
Virtual slides
Images hosted on other servers:
Cystic ovarian tumor
Cytology description
- Bland endometrioid cells (epithelial cells with moderate amounts of cytoplasm and bland, eccentrically placed nuclei) and fragments of ovarian type stroma (Diagn Cytopathol 2004 Jul;31:38)
Positive stains
- PAX8, estrogen receptor, progesterone receptor
- Nuclear beta catenin may be seen rarely; beta catenin alterations are better described in endometrioid borderline tumors (Int J Gynecol Pathol 2022 Feb 11 [Epub ahead of print], J Pathol 2006;208:708)
Negative stains
Sample pathology report
- Ovary, right, oophorectomy:
- Right ovary with endometrioid adenofibroma arising in a background of endometriosis
Differential diagnosis
- Endometriosis:
- Has associated endometrial type stroma with or without hemosiderin laden macrophages
- Serous cystadenoma / adenofibroma:
- Glands show only tubal type differentiation
- WT1, ER diffusely positive
- Membranous beta catenin staining
- Seromucinous cystadenoma:
- Glands show admixture of Müllerian epithelia with bland cytological features
- Ciliated, endocervical type, mucinous, endometrioid (which may have squamous or mucinous differentiation)
- Also associated with endometriosis
- Some authors believe that a subset of seromucinous cystadenomas represent benign endometrioid neoplasms with foci of mucinous or serous differentiation (Histopathology 2021;78:445)
- Glands show admixture of Müllerian epithelia with bland cytological features
Additional references
Board review style question #1
The image above shows a representative section of a 6 cm, solid and cystic ovarian mass. What is the diagnosis?
- Endometrioid adenofibroma
- Endometrioid borderline tumor
- Endometrioid carcinoma
- Endometriosis
- Fibroma
Board review style answer #1
Board review style question #2
What feature distinguishes endometrioid cystadenoma / adenofibroma from endometriosis?
- Absence of endometrial type stroma
- Epithelial lining
- Location
- Mucinous differentiation
- Size
Board review style answer #2
A. Absence of endometrial type stroma
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Reference: Endometrioid cystadenoma / adenofibroma
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Reference: Endometrioid cystadenoma / adenofibroma
