SRS250 - Radiological diagnosis of appendiceal mucocele—clinical correlation over 4-years

Abstract Objectives Appendiceal mucoceles are often incidental findings on CT scans. We aim to investigate the accuracy of CT diagnosis of appendiceal mucoceles in relation to intra-operative and histopathological findings. Methods This retrospective study included all patients with CT features suggestive of appendiceal mucoceles between January 2020 and June 2024. Data collection was taken from the department of radiology database and included: radiological features of extravasation, lymphadenopathy or metastases, endoscopic findings, referrals to peritoneal referral centres and patient-specific post-operative outcomes. Results 82 patients were included for analysis (48% males; mean age 66). 14 CT scans suggested concurrent appendicitis of whom eight underwent inpatient appendicectomy and two of these revealed low-grade mucinous neoplasms (LAMN) and appendiceal adenocarcinoma. Endoscopy was performed in 45 patients (55%), with the majority showing clear appendiceal orifices and benign disease; however, three cases had synchronous malignancy or incomplete procedures. Surgical intervention was undertaken in 50 patients, 32 did not undergo surgery due to frailty, significant co-morbidities or were monitored under surveillance. Of the 10 patients referred to tertiary centres, only 3 were found to have radiological extravasation or metastases and all underwent cytoreductive surgery. Post-operative complications occurred in eleven patients (22%), with 2 deaths (4%)—both following cytoreductive surgery. Conclusions Radiological features corelate variably with operative and histopathological findings, highlighting the necessity of multidisciplinary evaluation in suspected appendiceal mucoceles. The recent development of a peritoneal referral centre in Wales can only improve the management of these challenging cases.