Cumulus oophorus

Dr Yair Glick and Dr Matt A. Morgan et al.

Cumulus oophorus refers to an appearance in the ovary in which multiple granulosa cells enlarge around a developing oocyte. These support cells ("cumulus cells") serve multiple functions in the maturation of the oocyte. They may occasionally be seen during a pelvic ultrasound, and should not be confused with a pathological finding.

60-65% of the time a cumulus oophorus is visualised 12-24 hours before ovulation 3.

It comprises a collection of the cells in a mature follicle that protrude into the cavity of the follicle. It is a sign of imminent ovulation, but its absence has little significance in predicting the maturity of the oocyte. 

On ultrasound, the cumulus oophorus appears as a cyst along the wall of the dominant follicle

Radiographic features

  • it may be seen as a small anechoic cyst (or group of cysts) around a dominant follicle

Differential diagnosis

  • septated ovarian cyst: the stage of the menstrual cycle may help differentiate​
Ultrasound - gynaecology
Share article

Article information

rID: 42514
System: Gynaecology
Synonyms or Alternate Spellings:
  • ovigerus
  • proligerus disc
  • discus proligerus
  • proligerus membrane
  • cumuli oophori

Support Radiopaedia and see fewer ads

Updating… Please wait.

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.