This study aimed to provide an actualized classification system for acute pancreatitis (AP) by applying new principle and investigated the benefits of new classification.

Medical records and computed tomography (CT) images of 235 consecutive patients with AP admitted to the Ewha Womans University Mokdong Hospital between 2005 and 2010 were reviewed. The patients of severe pancreatitis who has necrosis were only 68 cases, these are too small for comparing to mild form. So we analyzed mild form of pancreatitis preferentially into two groups; group A, without morbidity and without organ failure (145 patients, mild acute pancreatitis, MAP); group B, with morbidity and without organ failure (22 patients, aggressive mild acute pancreatitis, AMAP). Clinical characteristics, laboratory findings, duration of hospitalization, need for the intensive care unit (ICU), organ failure, needs of intervention, another severity indexes and death were evaluated.

AMAP (group B) was higher proportion of need for the ICU care and of organ failure than MAP after age-adjusting (P<0.01). Also AMAP had higher incidence of associated malignancy, pseudocysts, and increasing fasting sugar level.

The AMAP is a different type of MAP. We need new category of different grade of mild form pancreatitis, because AMAP showed different clinical course. New classification of mild acute pancreatitis is relatively effective, and has clinically significant value.