Aims Malignant polyps are examined to assess histological features which predict residual tumour in the unresected bowel and guide surgical decision‐making. One of the most important of these features is resection margin involvement, although the best definition of margin involvement is unknown. In this study we aimed to investigate three different definitions and determine their impact on clinical outcomes. Methods and results One hundred and sixty‐five malignant polyps removed endoscopically were identified and histological features correlated with either residual tumour in subsequent surgical resections or tumour recurrence following a period of clinical follow‐up. Involvement of the polyp margin by cancer was defined in three different ways and outcomes compared. Tumour recurrence was associated with tumour grade, mucinous histology and resection margin involvement. All three definitions of margin involvement separated polyps into clinically significant categories; however, a margin ≤ 1 mm identified 73% of polyps as ‘high‐risk’ compared with 59.1% when involvement was defined as tumour within the zone of coagulation artefact at the polyp base or 50% when tumour was present at the margin. All three ‘low‐risk’ groups had a locoregional recurrence rate < 6.5%. Conclusions Definitions of margin involvement for endoscopically removed malignant polyps in the colon and rectum vary between health‐care systems, but a 1‐mm clearance is widely used in Europe and North America. Our results suggest that a 1‐mm margin is unnecessary and should be replaced by a definition based on tumour at the margin or within coagulation artefact at the polyp base.

ObjectiveEndoscopic ultrasound-guided through-the-needle microbiopsy (EUS-TTNB) forceps is a recent development that facilitates sampling of the walls of pancreatic cystic lesions (PCL) for histological analysis. We aimed to assess the impact of EUS-TTNB and its influence on patient management in a tertiary pancreas centre. DesignA prospective database of consecutive patients who underwent EUS-TTNB from March 2020 to August 2022 at a tertiary referral centre was retrospectively analysed. ResultsThirty-four patients (22 women) were identified. Technical success was achieved in all cases. Adequate specimens for histological diagnosis were obtained in 25 (74%) cases. Overall, EUS-TTNB led to a change in management in 24 (71%) cases. Sixteen (47%) patients were downstaged, with 5 (15%) discharged from surveillance. Eight (24%) were upstaged, with 5 (15%) referred for surgical resection. In the 10 (29%) cases without change in management, 7 (21%) had confirmation of diagnosis with no change in surveillance, and 3 (9%) had insufficient biopsies on EUS-TTNB. Two (6%) patients developed post-procedural pancreatitis, and 1 (3%) developed peri-procedural intracystic bleeding with no subsequent clinical sequelae. ConclusionEUS-TTNB permits histological confirmation of the nature of PCL, which can alter management outcomes. Care should be taken in patient selection and appropriately consented due to the adverse event rate.

Introduction The recent development of through-the-needle microbiopsy (TTNB) forceps via endoscopic ultrasound (EUS) has facilitated sampling of pancreatic cyst walls for histological analysis. This novel method has added to the armamentarium of the currently available radiological, biochemical and cytological modalities in the diagnostic algorithm of patients with pancreatic cystic lesions (PCL). We aimed to describe the utility of EUS-TTNB in influencing management outcomes at a tertiary hepatopancreatobiliary unit. Methods A prospective database of consecutive patients who underwent EUS-TTNB from March 2020 to October 2020 was retrospectively analysed. Recorded variables included patient demographics, technical success, histological results, adverse events and management outcomes. Results Seven patients (4 male; 3 female) were identified. All patients were discussed in dedicated multidisciplinary team (MDT) meetings and a consensus on the nature of the lesion was not possible. Seven patients had PCLs and one patient had a retroperitoneal cystic lesion. Technical success was achieved in 100% of patients. Specimen adequacy for definitive histological diagnosis was achieved in 85.7% of patients (n=6), leading to a change in management. An adverse event was encountered in one patient* who developed an infection of the cystic lesion post EUS-TTNB. After extensive MDT discussion, EUS guided drainage was performed resulting in good clinical response. The table summarises the key characteristics and outcomes of the patients. Conclusions Our case series has demonstrated EUS-TTNB to be a valuable and safe tool in the diagnostic pathway of patients with cystic lesions and led to a change in management in the majority of patients. Further larger prospective studies are required.