The lymphatic spread from the anterior pancreatic head is a complex network, but primarily involves a few key nodes: the celiac node (a principal node for spread of disease from the anterior pancreatic head), infrapyloric nodes, and periportal nodes (Fig. 2).

Axial CT sections with contrast in the portal venous phase. a Hypoenhancing mass in the anterior pancreatic head (long arrow), with slight flattening and deformation of the SMV (short arrow). b Disease infiltrates superiorly into the dorsal mesoduodenum (long arrow), demarcated by the gastroduodenal artery (arrow). c Enlarged infrapyloric node, indicating early involvement of disease spread (arrow)

Mesenteric spread from the anterior pancreatic head involves the following: the dorsal mesoduodenum (spread along GDA), the hepatoduodenal ligament (spread along the hepatic artery), the gastrohepatic ligament (spread along the left gastric artery), the gastrocolic ligament, (spread along the right gastroepiploic artery), and the transverse mesocolon (spread along the right and middle colic arteries) (Fig. 3).

Axial CT sections with contrast in the arterial phase (a) demonstrates heterogenous hypodense mass in the anterior pancreatic head (long arrow), with disease infiltrating adjacent structures and encasing the gastroduodenal artery (short arrow). Axial CT section with contrast in the portal venous phase (b) demonstrates infiltration of disease through the dorsal mesoduodenum into the duodenum, with early infiltration into the transverse mesocolon as well (arrow)

Direct spread of disease from the anterior pancreatic head involves adjacent structures including the common bile duct above the level of the ampulla, the proximal aspect of the 2nd segment of the duodenum, the distal stomach, and the transverse mesocolon, through which disease can reach the transverse colon and hepatic flexure (Figs. 3 and 4).

Axial CT sections with portal venous phase contrast. a Ill-defined hypodense mass in the anterior pancreatic head (arrow). b Obstruction of the common bile duct above the level of the ampulla (arrow)

Perineural spread from the anterior pancreatic head involves the right celiac ganglion (Fig. 5).

Axial CT section with arterial phase contrast. Ill-defined mass in the anterior pancreatic head, which encases the gastroduodenal artery (long arrow). Disease infiltrates close to the right celiac ganglion (short arrow)