Ovary
Other nonneoplastic lesions
Ectopic decidual reaction
Last author update: 1 February 2017
Last staff update: 21 November 2022 (update in progress)
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PubMed Search: Ectopic decidual reaction
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Pathophysiology | Diagnosis | Radiology description | Case reports | Treatment | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosis | Additional referencesCite this page: Busca A, Parra-Herran C. Ectopic decidual reaction. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ovarynontumorectopicdecidual.html. Accessed June 5th, 2023.
Definition / general
- Presence of ectopic decidualized uterine stromal cells in the ovary
Terminology
- Ectopic decidua or ovarian deciduosis
Epidemiology
- Associated with pregnancy
- In a study of 307 consecutives caesarean sections, macroscopic deciduosis was found in 31 (10.1%) of cases (Eur J Obstet Gynecol Reprod Biol 2016;197:54)
Sites
- Ectopic decidua has been described in the cervix, ovary and fallopian tube; also peritoneal surface, appendix, bladder, small and large intestine, mesentery, lymph nodes
Pathophysiology
- High levels of estrogen and progesterone during pregnancy induce mesenchymal fibroblast differentiation into decidual cells (Eur J Obstet Gynecol Reprod Biol 2016;197:54, Pathol Res Pract 1993;189:352, Korean J Obstet Gynecol 2011;54:373)
Diagnosis
- Often an incidental finding in surgical specimens or discrete nodule / mass discovered during caesarean section
Radiology description
- When the ovarian deciduosis is mass forming, it may be difficult to differentiate from a neoplastic process (Case Rep Obstet Gynecol 2015;2015:217367)
Case reports
- 31 year old woman with decidualized ovarian mass mimicking malignancy (Case Rep Obstet Gynecol 2015;2015:217367)
- 32 year old woman with ovarian deciduosis in pregnancy (Korean J Obstet Gynecol 2011;54:373)
Treatment
- Benign entity, no further treatment necessary; usually regresses 4 - 6 weeks postpartum
- If mass forming and imaging shows worrisome features for malignancy, the lesion is excised to establish the correct diagnosis
Gross images
Images hosted on other servers:
Ectopic decidual reaction
Microscopic (histologic) description
- Large polygonal cells with abundant eosinophilic cytoplasm, bland nuclei and visible nucleoli
Microscopic (histologic) images
Contributed by Aurelia Busca, M.D., Ph.D.
Deciduosis of ovarian stroma
Areas of deciduosis
Ovarian surface adhesions with deciduosis
Images hosted on other servers:
Left decidualized ovarian mass
Positive stains
Negative stains
- Cytokeratin
- Mesothelial markers (WT1, calretinin)
Differential diagnosis
- Endometriosis, which can also undergo decidualization during pregnancy
- The main difference is that the ectopic decidua has no glands (Gynecol Obstet Invest 2008;66:241)
- Epithelial ovarian neoplasm when mass forming
- Peritoneal mesothelioma or peritoneal carcinomatosis when there is additional involvement of peritoneal surface
Additional references
