Evaluation of Rosemont Classification for Non-calcific Chronic Pancreatitis (NCCP) Based on Histopathology: A Retrospective Study

Abstract

Introduction: Rosemont classification represents a consensus-based scoring system to standardize endosonographic diagnosis of chronic pancreatitis. To this date, its diagnostic accuracy has not been validated based on the gold standard, namely histopathology. The aim of this study was to assess the accuracy of Rosemont classification in NCCP patients undergoing total pancreatectomy and islet autotransplantation (TPIAT). Methods: Adult patients undergoing TPIAT for NCCP between July 2009 and January 2013 were included if they underwent endoscopic ultrasound (EUS) at our center within 1 year before surgery. The presence or absence of major and minor Rosemont criteria was determined by expert endosonographers using linear EUS. Patients were categorized into normal, indeterminate, suggestive, and consistent with CP based on the major and minor criteria as per the Rosemont classification. Histology was obtained at time of TPIAT from the resected pancreas by wedge biopsy of head, body, and tail. All histopathology was reviewed by a GI pathologist blinded to EUS features and clinical outcomes. Available pancreatic tissue was graded for severity of intralobular and perilobular pancreatic fibrosis by the Ammann classification system. A fibrosis score (FS) ≥2 was considered abnormal. Results: Fifty patients (42 females; mean age 37.9±10.8 years) underwent TPIAT with preoperative EUS during the study period. As expected, none of the patients had any major A feature as our study population consisted of only NCCP. None of our patients could be categorized into the “consistent” with CP category. Sensitivity, specificity, PPV, and NPV for “normal,” “indeterminate,” and “suggestive” of CP are shown in Table 1. A box plot is also shown.Table 1: Diagnostic Performance of Rosemont Classification Based on HistopathologyConclusion: In our study, Rosemont classification for NCCP correlated poorly with histopathology. Although Rosemont scoring adds more complexity, it may not improve the diagnostic accuracy of EUS for NCCP. Further attempts should be made to refine the EUS diagnostic criteria for CP to enhance its reliability in diagnosing NCCP.Figure 1