Pictorial review of bilateral adnexal lesions.

Bilateral adnexal lesions involve structures such as the ovaries, fallopian tubes, and surrounding tissues, arising from diverse etiologies, including inflammatory, infectious, neoplastic, and functional causes. Their variable presentation poses a diagnostic challenge in clinical practice, necessitating a multidisciplinary approach for accurate assessment and management. The American College of Radiology (ACR) introduced the Ovarian-Adnexal Reporting and Data System (O-RADS) as a standardized lexicon and risk stratification tool for evaluating adnexal lesions via ultrasound (US) and magnetic resonance imaging (MRI). While MRI is the most accurate modality for assessing indeterminate adnexal masses, bilateral lesions frequently present diagnostic dilemmas, particularly when they exhibit divergent O-RADS classifications or arise from different etiologies. The O-RADS system does not provide specific guidelines for bilateral lesions, requiring independent classification of each lesion, with management dictated by the highest assigned category. Certain pathologies demonstrate a propensity for bilateral involvement, underscoring the importance of recognizing their imaging characteristics and differential diagnoses. Integrating this knowledge into diagnostic reports enhances clinical decision-making and optimizes patient outcomes.