Which characteristic is true of phlegmonous pancreatitis?

Phlegmonous pancreatitis is characterized by the spread of inflammation beyond the pancreas itself, often affecting surrounding tissues. This condition is typically associated with a severe inflammatory process that can lead to complications such as necrosis or the formation of abscesses. The inflammatory response can indeed involve structures adjacent to the pancreas like the peritoneum and retroperitoneal space.

In contrast, encapsulated enzymes are more characteristic of pancreatic pseudocysts, while interstitial edema is generally seen in both acute and chronic pancreatitis but not specifically defining of phlegmonous pancreatitis. Additionally, phlegmonous pancreatitis is an acute condition and is not synonymous with chronic pancreatitis, which is a distinct and different disease process characterized by irreversible damage to the pancreatic tissue. Therefore, the characteristic that accurately defines phlegmonous pancreatitis is its propensity for causing inflammation to spread outside of the pancreatic tissue.