Fallopian tubes & broad ligament

Broad ligament

Developmental cysts

Topic Completed: 1 January 2017

Minor changes: 30 December 2020

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PubMed Search: paraovarian cyst

Aurelia Busca, M.D., Ph.D.
Carlos Parra-Herran, M.D.
Page views in 2020: 6,510
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Cite this page: Busca A Developmental cysts. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/fallopiantubesdevelopmentalcysts.html. Accessed October 23rd, 2021.
Definition / general
  • Benign paraovarian / paratubal cysts originating from remnants of the Müllerian (paramesonephric) and Wolffian (mesonephric) ducts or peritoneal mesothelial lining
Essential features
  • Benign adnexal cystic structures lined by unstratified epithelium, which can be flat, cuboidal (mesothelial and mesonephric cysts) or ciliated (paramesonephric cyst)
  • Underlying thin layer of smooth muscle (mesonephric and paramesonephric cysts)
  • Resection is curative
  • Also known as congenital cysts; terminology overlaps with paratubal / paraovarian cyst
  • Hydatids of Morgagni are variants of paramesonephric cysts, often multiple, pedunculated and connected to the fimbriae of the fallopian tubes
ICD coding
  • Q50.1
  • Approximately 10% of all adnexal masses
  • Most common are paramesonephric cysts
  • Adjacent to the adnexae, along broad ligament, between the fallopian tube and the ovary
  • Müllerian (paramesonephric) and Wolffian (mesonephric) ducts coexist during early development; remnants of these structures can become cystically dilated
  • Invaginations of the peritoneal lining give rise to mesothelial cysts
  • No specific etiological factors identified
Clinical features
Case reports
  • Excision by laparoscopy if large or symptomatic
  • Ovary and tube are spared in most cases
Gross images

Images hosted on other servers:
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Torsed paraovarian cyst before detorsion

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Torsed paraovarian cyst after detorsion

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Large paraovarian cyst

Microscopic (histologic) description
  • Paramesonephric cysts are lined by epithelium resembling fallopian tube mucosa, with single layer of ciliated columnar cells and thin smooth muscle wall
  • Mesonephric cysts contain a layer of cuboidal to columnar nonciliated epithelium and a thin smooth muscle wall
  • Mesothelial cysts are lined by single layer of flat or cuboidal cells with a thin wall with fibrous stroma; they lack ciliated cells seen in paramesonephric cysts
  • Distinction between these three types of cyst may be difficult, but has no clinical implications
Differential diagnosis
Additional references
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