Ultrasound and Histopathologic Correlation of Ovarian Cystadenofibromas: Diagnostic Value of the "Shadow Sign"

Ovarian Masses: The Value of Acoustic Shadowing on Ultrasound Examination

Adnexal lesions are a common finding in women and pose a clinical challenge since ovarian cancer is a highly lethal disease. However, most adnexal masses are benign, benefiting from a more conservative approach. In preoperative assessment, transvaginal ultrasound plays a key role in evaluating morphologic features that correlate with the risk of malignancy. The acoustic shadow is the loss of echo behind sound-absorbing components, such as calcifications or fibrous tissues, which are predominantly found in benign lesions. However, recognizing the acoustic shadow is a difficult skill to master, and its usefulness may be underappreciated.

Ultrasound Characteristics of Cystadenofibromas: A Retrospective Multicenter Study

ABSTRACT

Cystadenofibromas (CAFs) are relatively rare benign ovarian tumors. This study was to describe the ultrasound (US) findings of CAFs. Preoperative US information of 86 CAFs was retrospectively collected. To better illustrate their characteristic, 173 cystadenomas (CADs), 103 borderline ovarian tumors (BOTs), and 129 cystadenocarcinomas (CACs) were recruited as match groups. Besides morphology evaluation, tumors were categorized by the Ovarian-Adnexal Reporting and Data System US system. Higher-risk stratification in CAFs was more often being seen than CADs (63% of CAFs classified as Ovarian-Adnexal Reporting and Data System 4 or 5 vs 35% in CADs). Cystadenofibromas more commonly appeared as unilocular or multilocular solid than CADs. Solid components presented in 59% of CAFs and papillary projections presented in 45%. More CAFs contained solid components and papillary projections than CADs (P < 0.0001). When compared with BOTs and CACs, less CAFs contained solid components (P < 0.017 and P < 0.0001). However, no significant difference was found in CAFs versus BOTs or CACs about the presence of papillary projections. Shadowing was identified in 58% of CAFs; however, in CADs, BOTs, and CACs, the proportion was 2%, 11%, and 11%, respectively. Presence of shadowing in CAFs was noticeably more than CADs, BOTs, and CACs (P < 0.017 or P < 0.0001). Similar to CADs, most CAFs were avascular (76%) and without ascites (99%), which were significantly different from BOTs and CACs. We concluded that the sonographic markers for CAFs that differ from malignant were presence of shadowing, avascular, and absence of ascites.

Algorithmic Approach to Sonography of Adnexal Masses: An Evolving Paradigm

BACKGROUND

Pelvic US remains the workhorse for detection and characterization of adnexal masses in most centers worldwide. While the differentiation of benign from malignant masses remains the foremost concern, it is imperative to narrow the differential diagnosis for management of benign masses as well as prognostication of malignant masses. The IOTA group as well as ACR have described a five category classification system for adnexal lesions based on morphological patterns. In addition, a six category risk stratification has been proposed, incorporating the probability of malignancy as well as management recommendations.

LEARNING OBJECTIVES

1) Understand pattern based approach to adnexal lesion classification and the possible entities fitting into each pattern with the help of illustrations. 2) Classify lesions into appropriate risk categories based on diagnostic algorithms provided at the end of each section.

Microcystic pattern and shadowing are independent predictors of ovarian borderline tumors and cystadenofibromas in ultrasound

OBJECTIVES

To determine the sonographic characteristics of borderline tumors (BoTs) and cystadenofibromas (CAFs).

METHODS

Preoperative sonograms from consecutive patients who had at least one primary epithelial tumor in the adnexa were retrospectively collected. All tumors were described using the International Ovarian Tumor Analysis terminology. Ultrasound variables were tested using multinomial logistic regression after univariate analysis.

RESULTS

A total of 650 patients were included in this study. Of these, 110 had a CAF, 128 had a BoT, 249 had a cystadenoma (CAD), and 163 had a cystadenocarcinoma (CAC). Nearly half of CAFs and more than half of BoTs and CACs appeared to be unilocular and multilocular solid on the ultrasound images, while CADs were predominantly uni- or multilocular (p < 0.001). Overall, shadowing was identified in 82/650 cases. Sixty-five of 110 (59.1%) CAFs exhibited an acoustic shadow, compared with only 4/249 (1.6%) in CADs, 7/128 (5.5%) in BoTs, and 6/163 (3.7%) in CACs (p < 0.001). Furthermore, 112/650 cases demonstrated microcystic pattern (MCP). Sixty-eight of 128 (53.1%) BoTs exhibited MCP, compared with only 5/249 (2.0%) in CADs, 19/163 (11.7%) in CACs, and 20/110 (18.2%) in CAFs (p < 0.001). Logistic regression analysis revealed that shadowing is an independent predictor of CAFs, while MCP is an independent predictor of BoTs.

CONCLUSIONS

Sonographic findings for CAFs and BoTs were complex and partly overlapped with those for CACs. However, proper recognition and utilization of shadowing or MCP may help to correctly discriminate CAFs and BoTs.

KEY POINTS

• Sonographic findings for borderline tumors and cystadenofibromas are complex and mimic malignancy. • Microcystic pattern and shadowing are independent predictors of borderline tumors and cystadenofibromas respectively.