The Clinical Relevance of Distinguishing Between Simple and Complex Adnexal Cystic Structures by Ultrasound in Peri- and Postmenopause

<b>Background/Objectives</b>: We aimed to determine the reliability of simple ultrasound (US) markers and CA-125 measurements in diagnosing peri- and postmenopausal ovarian masses. <b>Methods</b>: The study was conducted in a retrospective setting. The preoperative imaging properties of peri- (PEM) and postmenopausal (POM) ovarian cysts were examined. Based on ultrasound findings, lesions were categorized as either (1) simple cysts, defined as unilocular, anechoic structures without solid components, or (2) complex cysts, characterized by any deviation from this morphology. Imaging characteristics, mass size, and demographic data were matched with histology and CA125 levels. <b>Results</b>: In total, 379 cystic structures (PEM: N = 195, average age: 45.6 years; range: 40-54 years, POM: N = 184, average age 61.2 years; range: 41-88 years) were analyzed. In the PEM group, there were 75 simple (Ø < 5 cm N = 32, Ø ≥ 5 cm N = 43) and 122 complex cysts (Ø < 5 cm N = 29, Ø ≥ 5 cm, N = 93), while in the POM group, 49 simple (Ø < 5 cm N = 9, Ø ≥ 5 cm N = 40) and 135 complex cysts (Ø < 5 cm N = 15, Ø ≥ 5 cm N = 120) were found. In the PEM group, malignancy was detected in complex cysts larger than 5 cm (N = 16, 17.58%). In the POM group, malignancy was present in 40 cases, and 3 of them proved to be smaller than 5 cm. The majority of cysts were functional (54.36%) in the PEM group. In the POM group, serous cysts were the most frequent (38.04%), followed by malignant (21.74%) and mucinous cysts (13.04%). CA125 was elevated in 66 of 217 cases (30.41%); only 23 were malignant (NPV: 0.95, PPV: 0.35). <b>Conclusions</b>: Functional cysts are frequently found among perimenopausal ovarian cysts, with malignancy occurring exclusively in complex cysts exceeding 5 cm in diameter. However, complex cysts of any size carry a significant risk of malignancy in menopause, thus, surgery is recommended. Simple cysts can be followed by serial scans in both groups. CA-125 does not give added value to the detection of malignancy in perimenopausal patients. However, in postmenopausal complex morphology cysts larger than 5 cm, it may give added value to the suspicion of malignancy.