Imaging in gynecological disease: clinical and ultrasound characteristics of benign retroperitoneal pelvic nerve sheath tumours

To describe the clinical and sonographic characteristics of benign, retroperitoneal, pelvic peripheral nerve sheath tumours (PNST). A retrospective, single, gynecologic oncology centre study conducted between 1/1/2018 and 31/8/2022. All ultrasound images, clips, and final specimens of benign PNSTs were reviewed to describe: (1) the ultrasound appearance of the tumours using standardised terminology, (2) the origin of the tumours in relation to nerves and pelvic anatomy, and (3) the correlation between ultrasound features and histotopograms. Five women (mean 53yr) with solitary benign, retroperitoneal, pelvic PNSTs were identified: four schwannomas and one neurofibroma. Four patients had surgical excision; one patient was managed conservatively with a trucut biopsy. All five PNSTs measured 31-50mm, were solid, moderately vascular tumours, with non-uniform echogenicity, well-circumscribed by hyperechogenic epineurium, and had no acoustic shadowing (figure 1). Some contained small, irregular, anechoic spaces (n = 3), and hyperechoic areas (n = 4), consistent with degenerative changes. Benign PNSTs were solid, non-uniform, vascular tumours without acoustic shadowing. No imaging characteristics differentiated between schwannomas and neurofibromas. In fact, they overlap with malignant tumours. Ultrasound-guided biopsies can help to confirm benignity in these tumours, which may then be monitored with ultrasound. 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.