Acute and Chronic Alcoholic Pancreatitis, Including Paraduodenal Pancreatitis

Context.—In the last 2 decades there has been significant progress in typing and recognition of pancreatitis, a necroinflammatory and fibroinflammatory process of multifactorial origin. Objective.—To present the current state of pathology and pathogenesis of alcohol-associated pancreatitis, including paraduodenal pancreatitis. In the context of the most important epidemiologic, clinical, and radiologic features, the related macroscopic changes and histopathologic characteristics are addressed. Data Sources.—In acute pancreatitis we discuss the pathologic findings that distinguish mild from severe pancreatitis and highlight autodigestive fat necrosis as the initial morphologic damage. In chronic pancreatitis we present a histologic staging system that describes the damage patterns as a necrosis-fibrosis sequence that takes place during the development of early to advanced and end-stage chronic pancreatitis. In paraduodenal pancreatitis the anatomic peculiarities are related to the sequence of morphologic changes that are correlated to the most important imaging findings. Pathogenetically, we discuss the role of alcohol overconsumption in triggering autodigestive fat necrosis in the pancreas, the repair of which results in a pancreas-transforming fibroinflammatory process. Conclusions—Whereas in acute pancreatitis there are no lesions that are diagnostic for alcohol overconsumption and that exclude other etiologies such as gallstone disease or drugs, the sequence of damage patterns in chronic pancreatitis are strongly related to the effect of alcohol overconsumption and allow in many cases the distinction from hereditary, autoimmune, or obstructive pancreatitis. Paraduodenal pancreatitis can be considered a special manifestation of alcoholic pancreatitis.