Advanced presentation of severe pancreatitis with extensive organizing peripancreatic and retroperitoneal collections. Hetergeneous enhancement near the tail could be related to fluid, thrombosed splenic vein, or necrosis. Evaluating the relationship of the collections to surrounding structures helps us to expand our understanding of anatomy of the retropertineum (most) and lesser sac projecting anteriorly under the stomach and displacing the transverse colon.