The shading sign: is it exclusive of endometriomas?

Objectives: To investigate if the shading sign is an exclusive MRI feature of endometriomas or endometrioid tumors, and to analyze its different patterns. Methods: Three hundred and fourty six women with adnexal masses who underwent 1.5/3-T MRI were included in this retrospective, board-approved study. The shading sign was found in 56 patients, but five cases were excluded due to lack of imaging follow-up or histological correlation. The final sample included 51 women. The type of tumor and the pattern of shading were recorded for each case. Results: Thirty endometriomas and five endometrioid carcinomas were found. The remaining 16 cases corresponded to other benign and malignant tumors. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 93%, 59%, and 96%, respectively. Restricting the analysis to cystic lesions without solid or fat component, sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 96%, 94%, and 80%. Five shading patterns were identified: layering (15.7%), liquid–liquid level (11.8%), homogenous (45.1%), heterogeneous (11.8%), and focal/multifocal shading within a complex mass (19.6%). No significant correlation was found between these patterns and the type of tumor. Conclusions: The shading sign is not exclusive of endometriomas or endometrioid tumors. Homogenous shading was the most prevalent pattern in endometriomas and half of the cases with focal/multifocal shading within a complex mass were endometrioid carcinomas.

Primary lymphomas of the female genital tract: imaging findings

Primary lymphomas of the female genital tract are extremely rare, and a definitive diagnosis requires correlation of the clinical, radiological, and pathological findings. Unlike nonlymphomatous malignant tumors, the treatment of lymphoma is typically nonsurgical, thus raising the possibility of lymphoma in the differential diagnosis of a pelvic mass, a radiologist can significantly change the approach to the disease. Although some imaging findings may appear nonspecific, others may suggest the possibility of lymphoma, such as the presence of one or more solid, well-defined, homogeneous masses without necrosis despite a large size or the presence of diffuse infiltration leading to organomegaly with architectural preservation. Additionally, pelvic lymphadenopathy may be evident. In this pictorial essay, we discuss the radiological appearances of gynecological primary lymphomas, grouped by organ, in ultrasonography, computed tomography, and magnetic resonance imaging.