Pelvic ultrasound: a powerful tool in managing the patient with an adnexal mass
In this retrospective observational cohort study, Alcázar et al used the International Ovarian Tumor Analysis (IOTA) descriptive classification system to report the clinical outcome in 99 asymptomatic postmenopausal women with purely solid ovarian lesions, without significant color flow and without ascites or carcinomatosis.6,7 In 42 women with a histologic diagnosis, the most common etiology was fibroma (62%) and fibrothecoma (12%). In 57 patients followed conservatively, all remained asymptomatic and there was no change in the size or appearance of the lesion with a median follow-up time of 36 months. Stage 1 primary ovarian cancer was reported in two patients, resulting in a 2% (95% confidence interval [CI] 0.1-7.5) risk of malignancy. The low risk of malignancy led these authors to conclude that conservative management may be an option.6 Wang and Johnson reported on 29 patients with homogeneous solid adnexal masses with well-circumscribed margins, attenuation, and minimal or no vascular flow. No evidence of malignancy was identified in either those who underwent surgery or were followed conservatively. In the group of postmenopausal patients followed with ultrasound, the masses either remained unchanged or decreased in size.8 Froyman et al reported on the risk of malignancy in 181 presumed fibromas/fibrothecomas regardless of patient age. In this group, there were 13 (7.2%) malignancies including 3 that were felt to be “certainly benign” and 7 that were considered “probably benign.” A subgroup of this study included 78 solid tumors thought to be ovarian fibromas with smooth contour, acoustic shadowing, and absent or minimal color flow; ovarian cancer was detected in 2 (2.6%). These authors concluded that the risk of malignancy was high enough that these masses should not be removed by laparoscopic morcellation.9 In addition to the risk of malignancy, solid ovarian masses such as thecoma or fibrothecoma may secrete estrogen that results in endometrial hyperplasia or androgens, resulting in virilization.10 They can also be seen in conjunction with other syndromes such as Meigs syndrome (ovarian fibroma, hydrothorax, ascites).10
An asymptomatic pelvic mass is not an uncommon finding in the postmenopausal patient. Transvaginal ultrasound is a powerful tool that can be used to reliably assess the risk of malignancy. In 2010, The Society of Radiologists in Ultrasound (SRU) published a consensus statement on the management of asymptomatic ovarian masses, recognizing that simple ovarian cysts (round/oval, anechoic, smooth thin wall, no solid components or septations, posterior acoustic enhancement, and no abnormal internal color flow) are unlikely to be malignant and can be followed up by ultrasound, even in postmenopausal women.11 Alcázar et al have extended the consideration of conservative management to purely solid ovarian lesions with no or minimal blood flow and absence of ascites or carcinomatosis, recognizing the “low” (2%) risk of malignancy.