Which of the following complications is NOT commonly associated with acute pancreatitis?

Acute pancreatitis can lead to several complications due to the inflammatory process and the leakage of pancreatic enzymes into surrounding tissues. Among these, phlegmon, pseudocyst, and abscess formation are all commonly recognized complications.

Phlegmon refers to a diffuse inflammatory response involving the connective tissue surrounding the pancreas, which can occur due to the inflammation from pancreatitis. Pseudocysts are fluid-filled sacs that can develop in the pancreas or surrounding tissues as a result of local inflammation or necrosis, often seen in the context of acute or chronic pancreatitis. Abscess formations can also occur, where infection leads to localized collections of pus in the abdominal cavity.

In contrast, splenomegaly, or enlargement of the spleen, is not a direct complication of acute pancreatitis. While it may theoretically occur due to portal hypertension or other systemic effects of severe pancreatitis, it does not typically develop as a direct complication in the same way as the others. Therefore, splenomegaly is the least associated with acute pancreatitis compared to the other listed complications. This distinction makes it the correct answer to indicate the complication that is not commonly associated with acute pancreatitis.