Cystic lesions of the pancreas (differential)

The differential for cystic lesions of the pancreas includes:

• unilocular
  • pancreatic pseudocyst
  • intraductal papillary mucinous neoplasm (IPMN)
  • serous cystadenoma uncommonly uni/macrolocular
  • simple pancreatic cyst
  • cystic neuroendocrine tumor of the pancreas
• diffuse pancreatic cysts
  • pancreatic cysts occur in association with 
    • von Hippel Lindau syndrome
    • autosomal dominant polycystic kidney disease (ADPKD)
    • cystic fibrosis
• macrocystic: multilocular
  • mucinous cystic neoplasm of the pancreas: usually body and tail
  • intraductal papillary mucinous neoplasm (IPMN)
  • serous cystadenoma uncommonly uni/macrolocular
  • acinar cell cystadenocarcinoma
  • hydatid cyst ¹²
• microcystic
  • serous cystadenoma: usually head; 30% have a central scar
• cystic with a solid component
  • walled-off pancreatic necrosis
  • macrocystic tumors can also have a solid component
  • solid pseudopapillary tumor of the pancreas
  • primary ductal pancreatic tumor with cystic degeneration 
  • cystic degeneration of islet cell tumors (neuroendocrine tumors)
    • insulinoma
    • glucagonoma
• cystic teratoma
• metastases to pancreas

Retroperitoneal lesions (extrinsic to the pancreas) can mimic pancreatic cystic lesions, when close to the gland. Examples include:

• cystic lymphadenopathy (e.g. necrotic)
• duodenal diverticulum

Practical points

The American College of Radiology (ACR) published guidelines on managing incidental cystic pancreatic lesions in 2017 ¹¹.