Gemma Rossi

Autoimmune pancreatitis (AIP) represents a benign inflammatory disease, with two subtypes and specific histological and serological features (IgG4 presence in the tissue) [1]. In contrast, intraductal papillary mucinous neoplasia (IPMN) represents a potential malignant cystic disease, with a range of benign, borderline (the presence of worrisome features or high risk stigmata) or malignant disease manifestations [2]. Sometimes these two entities can present themselves with unusual clinical manifestations and endoscopic ultrasound (EUS) represents the choice exam to high-accurate diagnosis in both diseases [3]. A 54-year-old man with a systemic hypereosinophilia conditioning renal and pulmonary manifestations presented in our referral hospital for pancreatic diseases to perform an EUS with the suspect of a degenerated IPMN, with multiple nodules projecting into the main pancreatic duct (MPD) already evaluated and biopsied in another center resulting in inflammatory infiltration (eosinophils, plasma cells and lymphocyte infiltration, negative for IgG4 immunohistochemistry) and studied at a previous magnetic resonance. EUS revealed a solid, hypoechoic, rigid, vascularized lesion located filling the MPD at the level of pancreatic body causing upstream ductal dilatation (up to 6 mm in the tail). The dilated MPD was also communicating with a branch-duct cyst, suggestive of a mixed-type IPMN ([Fig. 1]). This nodule was suggestive after the intravenous contrast injection for a solid-vascularized lesion, with an early enhancement in the arterial/early phase and a slow wash-out in the venous/late phase ([Video 1]). Other smaller cysts with solid material inside were evidenced along the pancreatic gland ([Fig. 2]). A fine needle aspiration with on-side cytologic evaluation (ROSE) of the solid lesion filling the MPD described in the pancreatic body was performed which revealed the presence of an IPMN with low grade dysplasia. The patient underwent surgical resection (distal splenopancreatectomy) and definitive histology described the intraductal nodule of the pancreatic body as a type-1 autoimmune IgG4 related pancreatitis with a rich eosinophilic infiltrate associated with a low-grade dysplasia branch duct IPMN. Plasma cells IgG4+ were numerous in the tissue but the serological dosage of IgG4 was negative ([Fig. 3], [Fig. 4]). The patient is now undergoing Rituximab infusions (two infusions performed) and no imaging has been performed yet. AIP could present atypical manifestations and can also mimic potentially malignant disease like IPMN. Although EUS represents the method of choice for pancreatic masses diagnosis, in this specific case the final histological evaluation of the surgical sample resulted in a unique and final way to reach the correct diagnosis. Finally, the study of the case in a referral center with an expert team in pancreatic diseases is fundamental to establish the correct management, diagnosis and therapy. Endoscopy_UCTN_Code_CCL_1AF_2AZ_3AB Article published online: 27 April 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Background: Bacterial migration from the oral cavity to the upper gastrointestinal tract has been proposed as a contributor to pancreatic ductal adenocarcinoma (PDAC) onset and prognosis. Whether PDAC is associated with alterations of the oral–duodenal microbiome continuum remains unclear. Methods: In this prospective study, we profiled matched saliva and duodenal brushings from 24 treatment‐naïve PDAC patients without ducts obstruction and 24 age‐ and sex‐matched healthy controls (HC). Microbial composition was assessed by 16S rRNA gene sequencing. α ‐Diversity was evaluated using Faith's phylogenetic diversity (PD), observed ASVs, and Pielou's evenness; β ‐diversity using UniFrac, Bray–Curtis, and distance‐based redundancy analysis (db‐RDA). Associations with overall survival were examined using Cox models and ROC‐derived cut‐offs, with leave‐one‐out cross‐validation for robustness. Results: Duodenal Faith's PD was significantly lower in PDAC than HC ( q = 0.034), whereas richness and evenness did not differ; no α ‐diversity differences were observed in saliva. After adjustment for diabetes and periodontitis, lower duodenal Faith's PD ( q = 0.048) and ASV richness ( q = 0.030) in PDAC remained significant. β ‐Diversity was primarily driven by body site, but adjusted db‐RDA revealed a small yet significant PDAC–HC difference in duodenal community composition (pseudo‐F = 2.16, p = 0.002). Several genera showed differential abundance between groups. Higher salivary phylogenetic diversity predicted longer survival (aHR = 0.19, p = 0.001), along with specific genera associated with favourable prognosis. Discussion: PDAC is associated with reduced duodenal phylogenetic diversity and subtle disease‐related shifts in duodenal microbiota, independent of major confounders and in the absence of duct obstruction. Both α ‐diversity and selected genera may hold prognostic relevance, supporting further validation in larger, stage‐stratified cohorts.

In recent years, small pancreatic neuroendocrine tumors (pNETs) have shown a dramatic increase in terms of incidence and prevalence, and endoscopic ultrasound (EUS) radiofrequency ablation (RFA) is one potential method to treat the disease in selected patients. As well as the heterogeneity of pNET histology, the studies reported in the literature on EUS-RFA procedures for pNETs are heterogeneous in terms of ablation settings (particularly ablation powers), radiological controls, and radiological indications. The aim of this review is to report the current reported experience in EUS-RFA of small pNETs to help formulate the procedure indications and ablation settings. Another aim is to evaluate the timing and the modality of the radiological surveillance after the ablation. Moreover, new studies on large-scale series are needed in terms of the safety and long-term oncological efficacy of RFA on these small lesions.

Gastric cancer in 2022: Is there still a role for endoscopic ultrasound?

Objective: Endoscopic ultrasound (US)‐guided radiofrequency ablation (RFA) has been investigated for pancreatic ductal adenocarcinoma (PDAC) but studies are limited and heterogeneous. Computed tomography (CT) scan features may predict RFA response after chemotherapy but their role is unexplored. The primary aim was to investigate the efficacy of ex‐vivo application of a dedicated RFA system at three power on surgically resected PDAC in patients who underwent neoadjuvant chemotherapy. The secondary aim was to explore the association between pre‐treatment CT‐based quantitative features and RFA response.Methods: Fifteen ex‐vivo PDAC samples were treated by RFA under US control at three power groups (10, 30, and 50 W). Short axis necrosis diameter was measured by two expert blinded pathologists as the primary outcome. Two radiologists independently reviewed preoperative CT images.Results: Eighty percent of specimens showed coagulative necrosis consisting of few millimeters: 5.7 ± 3.9 mm at 10 W, 3.7 ± 2.2 mm at 30 W, and 3.5 ± 2.4 mm at 50 W (p = 0.3), without a significant correlation between power setting and mean necrosis short axis (rho = –0.28; p = 0.30). Good agreement was seen between pathologists (k = 0.76; 95% confidence interval 0.55–0.98). Logistic regression analysis did not show associations between CT features and RFA response.Conclusions: RFA causes histologically evident damage with coagulative necrosis of a few millimeters in 80% of ex‐vivo PDAC samples after chemotherapy and no clinical or pre‐operative CT features can predict efficacy. Power settings do not correlate with the histological ablation area. These results are of relevance when employing RFA in vivo and planning clinical trials on its role in PDAC patients.

Endoscopic ultrasound-ablation with HybridTherm-Probe (EUS-HTP) significantly reduces tumour volume (TV) in locally-advanced pancreatic ductal adenocarcinoma (LA-PDAC). We aimed at investigating the clinical efficacy of EUS-HTP plus chemotherapy versus chemotherapy (HTP-CT and CT arms) in LA- and borderline-resectable (BR) PDAC, with 6-months progression-free survival (6-PFS) rate as primary endpoint. In a phase-II randomized-controlled-trial, 33 LA/BR-PDAC patients per-arm were planned to verify 20% improved 6-PFS rate. Radiological response (Choi criteria), TV and serum CA19.9 were assessed up to 6-months. Seventeen and 20 LA/BR-PDAC patients were randomized to HTP-CT or CT. Baseline and CT-related features were balanced. At 6-months, 6-PFS rate was 41.2% and 30% in HTP-CT and CT arms (p = 0.48), respectively. A decrease ≥50% of serum CA19.9 was achieved in 75% and 64.3% of HTP-CT and CT patients (p = 0.53), respectively. TV reduced up to 6-months in 64.3% and 47.1% of HTP-CT and CT patients (p = 0.35), respectively. Resection rate, PFS-time and overall survival (OS-time) were similar. HTP-CT achieves a non-significant 11.2%, 10.7% and 17.2% improved 6-PFS, CA19.9 decrease ≥50% and TV reduction rates over CT, without any impact on resection rate, PFS-time and OS-time. As the study was underpowered, these results suggest further investigation of EUS-local ablation in selected patients with localized disease after induction CT.