Presentation
Patient presenting for follow up of IUD placement.
Patient Data
There is a 5.5 cm anechoic lesion in the left ovary (there are a few artifactual low level echoes on some images). There are a few round structures at the border (compatible with a normal cumulus oophorus), but no wall thickening, nodularity, papillary projection or thickened septation. No flow on color Doppler imaging.
Case Discussion
This is an example of a normal ovarian follicular cyst. The cyst is on the larger size (5.5 cm), but the young/premenopausal status of the patient and the lack of any aggressive features is compatible with a dominant Graafian follicle that failed to rupture. These classically resolve in 1-2 menstrual cycles and persistent cysts raise other lesions into the differential diagnosis (such as serous cystadenoma), although other options on the differential would be much less common in this age than a physiologic cyst. Some follow up a follicular cyst between 5-7 cm with ultrasound in one year, to ensure that it resolves. MRI is usually performed if there are possible aggressive features or if the cyst is >7 cm.