Imaging-guided classification and diagnostic pathways for appendiceal abscesses: Results from the 2025 Italian Society of Research in Surgery/Italian Society of Emergency and Trauma Surgery consensus conference

Background: Imaging plays a pivotal role in the diagnosis and stratification of appendiceal abscess, a distinct phenotype of complicated appendicitis. Persistent heterogeneity in anatomic terminology, radiological grading, and diagnostic pathways continues to hinder reproducibility, clinical decision-making, and cross-study comparability. A standardized, imaging-centered framework integrating reproducible anatomic descriptors, validated severity grading, and evidence-based imaging strategies is therefore urgently needed. Methods: Under the auspices of the Italian Society of Research in Surgery and the Italian Society of Emergency and Trauma Surgery, a multidisciplinary expert panel conducted a 4-round modified Delphi process, culminating in an in-person consensus conference held in Rome on November 6, 2025. Statements were iteratively refined through anonymous voting, achieving predefined thresholds for consensus (≥80%) and strong consensus (≥95%). Results: The panel endorsed (1) mandatory anatomotopographic classification of appendiceal abscess (pelvic, mesenteric, retrocecal/retrocolic, and anterior with abdominal wall involvement); (2) adoption of the Jeffrey radiological grading system (grades 1-3: phlegmon/small abscess ≤3 cm; well-circumscribed abscess >3 cm; and extensive/poorly defined with multicompartment extension); and (3) structured imaging recommendations. These include contrast-enhanced computed tomography as the reference modality in adults, with selective use in suspected malignancy, particularly in patients >50-55 years, ultrasound-first/magnetic resonance imaging-second pathways during pregnancy, and symptom-driven follow-up after conservative management. Conclusion: This consensus establishes a unified and imaging-guided diagnostic framework that harmonizes anatomotopographic localization with reproducible radiological stratification and pathway-oriented recommendations. Standardized definitions and structured reporting are expected to reduce practice variability, enhance interpretative consistency, and enable reliable cross-institutional and cross-study comparisons. These statements complement, rather than replace, clinical judgment and are aligned with recent international updates, including the 2025 World Society of Emergency Surgery Jerusalem Guidelines. Prospective multicenter validation is warranted to assess their impact on clinical outcomes, drainage success, recurrence prediction, and the prognostic performance of the integrated anatomotopographic-Jeffrey approach.