Evaluation of Rosemont criteria for non-calcific chronic pancreatitis (NCCP) based on histopathology – A retrospective study

Background Rosemont classification for chronic pancreatitis has not been evaluated specifically in non-calcific chronic pancreatitis (NCCP) patients and to this date, it has not been correlated with the gold standard namely histopathology. Objective To assess the correlation of EUS Rosemont criteria for NCCP with histopathology from surgical specimens and evaluate the impact of age, sex, BMI, smoking and alcohol on Rosemont classification. Methods Adult patients undergoing TPIAT for NCCP between July 2009 and January 2013 were identified from our institutional database. The presence or absence of standard and Rosemont (major and minor) criteria were determined by expert endosonographers using linear endosonography. Patients were categorized into normal, indeterminate and suggestive with CP based on Rosemont classification. Histology was obtained at time of TPIAT from the resected pancreas by wedge biopsy of head, body and tail. All histopathology were re-reviewed by a GI pathologist blinded to endosonographic features and clinical outcomes. Available pancreatic tissue was graded for severity of intralobular and perilobular pancreatic fibrosis by the Ammann classification system. Results 50 patients with NCCP (42 females, mean age± SD = 37.9 ± 10.8) underwent TPIAT with preoperative EUS during the study period. Univariate analysis of features such as age, sex, BMI, smoking and alcohol history showed no significant difference between patients identified as normal and those identified as indeterminate/suggestive (p > 0.05). Rosemont “Normal” was poor in excluding CP as 5/9 patients (55.5%) had CP on histopathology. 25/26 patients (96.2%) with features “suggestive” of CP had evidence of CP on histopathology. 12/15 patients (80.0%) with “indeterminate” features had CP on histopathology. Conclusions Rosemont classification can be used independent of patient characteristics (age, sex and BMI) and environmental factors (smoking and alcohol exposure). In our cohort, Rosemont classification was strongly predictive of CP in patients with features “suggestive” of CP. However, “normal” Rosemont classification had poor correlation in this study. This is maybe due to lack of true comparator “normal” pancreas which cannot be obtained reasonably. The strength of agreement for diagnosis of CP was substantial between the standard and Rosemont criteria.