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 of 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
- it may be seen as a small anechoic cyst (or group of cysts) around a dominant follicle
- septated ovarian cyst: stage of the menstrual cycle may help differentiate
History and etymology
The word "cumulus oophorus" literally means "heap of eggs".
- 1. Tanghe S, Van Soom A, Nauwynck H et-al. Minireview: Functions of the cumulus oophorus during oocyte maturation, ovulation, and fertilization. Mol. Reprod. Dev. 2002;61 (3): 414-24. doi:10.1002/mrd.10102 - Pubmed citation
- 2. Laing FC, Allison SJ. US of the ovary and adnexa: to worry or not to worry?. Radiographics. 2012;32 (6): 1621-39. doi:10.1148/rg.326125512 - Pubmed citation
- 3. Timor-Tritsch IE, Rottem S. Transvaginal sonography. Elsevier Science Ltd. ISBN:0444015779. Read it at Google Books - Find it at Amazon
- 4. Cacciatore B, Liukkonen S, Koskimies AI et-al. Ultrasonic detection of a cumulus oophorus in patients undergoing in vitro fertilization. J In Vitro Fert Embryo Transf. 1986;2 (4): 224-8. Pubmed citation
Ultrasound - gynaecology
- ultrasound (introduction)
- acute pelvic pain
- chronic pelvic pain
- Mullerian duct anomalies
- ovarian follicle
- ovarian torsion
- pelvic inflammatory disease
- ovarian cysts and masses
- ovarian cyst
- corpus luteum
- haemorrhagic ovarian cyst
- ruptured ovarian cyst
- ovarian epithelial tumours
- granulosa cell tumours of the ovary
- paraovarian cyst
- polycystic ovaries
- ovarian hyperstimulation syndrome
- post-hysterectomy ovary
- fallopian tube