OP17.07: Uterine leiomyosarcoma: the tumour hidden in plain sight

Diagnostic performance of US, CT and MRI in the identification ULMS was assessed over a decade, analysing preoperative imaging in 13 cases. The research addresses the difficulty of differentiating ULMS from leiomyoma due to overlapping imaging characteristics, the limitations of hysteroscopic biopsies, and frequent misdiagnoses of the “multifibroid uterus”. US and CT, when meticulously analysed, can accurately diagnose ULMS, but relies upon the radiologists' familiarity with ULMS's typical imaging appearances on US and CT. We propose leveraging US and CT findings to direct clinicians towards structured diagnostic imaging pathways, incorporating MRI and Molecular Imaging. Highlighting the radiologist's pivotal role in tumour differentiation, we advocate for strategic imaging pathways to aid in surgical planning and mitigate the risk of disseminating the disease. A retrospective review was conducted on the medical imaging used for diagnosing ULMS in an Australian state from 2012-2022, identifying 13 cases through a state pathological database. Data collected included imaging modalities used, radiological suspicion, and surgical outcomes, with analysis of imaging usage rates, surgical approach, diagnostic accuracy, and decision-making correlations. Preoperative imaging largely relied on US (77% of cases), with CT used in 92% and MRI in one case. PET-CT was not utilised. Only 15% received a preoperative LMS diagnosis based on imaging. Incidental diagnoses post-total abdominal hysterectomy (TAH) occurred in 38%, highlighting preoperative detection challenges. Despite 53% having a preoperative malignancy diagnosis, no surgeries were documented as 'contained'. The audit reveals reliance on US and CT for ULMS assessment, recommending more integrated use of both standard and advanced imaging techniques in line with guidelines to enhance diagnostic accuracy and patient care. It emphasises the need for continuous education and strategy updates among healthcare professionals for accurate ULMS identification and differentiation from benign leiomyomas. Supporting information for OP01.05, OP01.06, OP02.05, OP03.01, OP04.03, OP04.04, OP04.09, OP05.04, OP05.08, OP08.01, OP08.02, OP08.06, OP08.08, OP10.04, OP10.05, OP10.07, OP10.08, OP11.01, OP11.04, OP12.05, OP13.08, OP14.01, OP14.06, OP15.09, OP16.01, OP17.03 can be found in the online version of these abstracts.