Abstract
A 10-year-old Schnauzer presented with a 1-month history of vomiting, anorexia, and abdominal pain, and a recently detected intra-abdominal mass. The round, soft-tissue opacity masses identified on the radiography in the left mid-abdomen were confirmed as multifocal, cystic masses via ultrasonography. The necrotic masses mimicked an intra-abdominal neoplasia on the initial imaging examinations. The computed tomography (CT) clearly showed encapsulated masses with a necrotic fluid arising from the left limb of the pancreas and extending to the peripancreatic, paracolic, and perigastric regions. Based on the multimodal imaging, surgical exploration, and histopathology, the mass was diagnosed as a walled-off pancreatic necrosis (WOPN). CT is an effective diagnostic modality for diagnosing acute pancreatitis in WOPN.