Ovarian Masses and O-RADS

A Systematic Approach to Evaluating and Characterizing Adnexal Masses With Ultrasound

Ana Mitchell, MD; Austin Kwong, MD; Simran Sekhon, MD; John P McGahan, MD, FACR


Appl Radiol. 2021;50(3):24-31. 

In This Article

Peritoneal Inclusion Cysts

One mimic of a surface epithelial neoplasm is a benign entity called a peritoneal inclusion cyst, which may be mistaken for a complex cystic ovarian mass. Peritoneal inclusion cysts represent fluid "trapped" within the peritoneal adhesions in patients with previous history of abdominal or pelvic surgery, Crohn disease, or prior pelvic inflammatory process. These "cysts" are not spherical, but they may be oblong with more acute angulations at their margins, as the fluid is interposed between different surfaces within the pelvis (Figure 4). History is helpful in such cases. There should be no mural nodularity. They need only be evaluated with ultrasound or, if detected with CT, they require no further evaluation.