Pancreatic adenocarcinoma: This is the most common cause of a pancreatic uncinate mass presenting with jaundice, due to the tumor's location which can obstruct the bile duct, leading to jaundice. The uncinate process of the pancreas is a common site for pancreatic cancer.

Ampullary carcinoma: A tumor arising from the ampulla of Vater can cause obstructive jaundice and may present as a mass in the uncinate process of the pancreas.
Cholangiocarcinoma: Although less common than pancreatic adenocarcinoma, cholangiocarcinoma, especially the periampullary type, can present with jaundice and a mass in the pancreatic head or uncinate process.
Duodenal carcinoma: A carcinoma of the duodenum, particularly in the second or third portion, can invade the uncinate process of the pancreas and cause jaundice by obstructing the bile duct.

Lymphoma: Although less common, lymphoma involving the pancreas can present with a mass and obstructive jaundice. Missing this diagnosis could lead to a delay in appropriate treatment.
Metastatic disease to the pancreas: Metastases from other primary cancers (e.g., renal cell carcinoma, lung cancer) can present as a pancreatic mass and cause jaundice. Recognizing this possibility is crucial for proper staging and treatment planning.

Solid pseudopapillary neoplasm (SPN): A rare pancreatic tumor that can present as a mass but is less likely to cause obstructive jaundice unless it is large and located in a strategic area.
Pancreatic neuroendocrine tumors (PNETs): While PNETs can cause a variety of symptoms depending on their functional status, they are less commonly associated with obstructive jaundice unless they are large or located near the bile duct.
Intraductal papillary mucinous neoplasm (IPMN): Although IPMNs can cause obstructive jaundice, they are more commonly associated with a dilated pancreatic duct and less frequently present as a discrete mass in the uncinate process.