EP24.16: Malignant transformation of a typical endometrioma through the years: a case report

Endometriosis is a common benign disease, but there is molecular and biological evidence suggesting its association with ovarian endometrioid and clear cell cancers. Considering the risks and benefits of surgery, it is important to identify patients at high risk for malignant transformation. Risk factors are tumour size, postmenopausal status and age ≥45 years. Solid tissue or papillary projections as well as vascularization are associated with atypical endometriomas, more frequently at risk of transformation. We present the case of a 58-years old patient with a history of endometriosis who previously had LPS enucleation of right ovarian endometrioma in 2011. She underwent regular ultrasound examinations: in 2013 a transabdominal exam described a right ovarian cyst of 28 mm. In 2017 a transvaginal exam defined the same cyst as unilocular of 24mm with regular margins, ground glass content, non-vascularised. In 2020 the unilocular, regular, non-vascularised cyst of 27mm showed anechoic content. Ultimately, she presented with pelvic pain in January 2024. The ultrasound described a right multilocular solid mass of 101mm, with multiple solid components (largest with cockade-like aspect), anechoic content and moderate vascularization. Final pathology was endometrioid cancer. We believe this to be the malignant transformation of a typical endometrioma, confirming that in menopause they should be monitored even if they are small. Further analysis should be conducted on the hypothesis that a change in echogenicity could be a sign a of malignant transformation before it occurs. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.