Histopathological and immunohistochemical studies on apparently uninvolved areas of pancreas in patients with acute pancreatitis.

Apparently uninvolved areas of the pancreas that were distant from frank parenchymal necrosis in nine patients with acute pancreatitis were histopathologically and immunohistochemically studied. Fibrosis in these areas was observed in seven patients with an illness of 8 days or longer, and it was mainly distributed in the interlobular spaces and accompanied by hemosiderin deposition. Fibrosis was increased and divided into linear and broad types according to the presumed stage of evolution. Fibrosis immunostained it was negative against anti-collagen type I in three patients with an illness of 2 or 3 months was positive against anti--collagen in the interlobular spaces in the two remaining patients, whose illness was of less than 5 days' duration. Fibrosis in the apparently uninvolved areas in patients with acute pancreatitis therefore appears to have developed in relation to acute pancreatitis, and it may consist of type I collagen in longer surviving patients.