Simple mucinous cyst: another potential cancer precursor in the pancreas? Case report with molecular characterization and systematic review of the literature

Virchows Arch. 2021 Jul;479(1):179-189. doi: 10.1007/s00428-021-03029-1. Epub 2021 Jan 28.


Cystic lesions of the pancreas may range from benign to precursors of pancreatic cancer. Simple mucinous cyst (SMC) is larger than 1 cm, has a gastric-type flat mucinous lining, and minimal atypia without ovarian-type stroma. We report a new case of pancreatic SMC, coupling a systematic review of the English literature mainly focused on their clinic-pathological features. We reviewed 103 cases of SMC in adults (73 women), averaging 57 (range, 26-70) years. The SMCs were located in the body-tail region of the pancreas in 60 (58%) cases, presenting as single cystic lesions in 94% of cases; 43% of patients were asymptomatic. A preoperative fine-needle aspiration of the cyst fluid detected amylase and carcinoembryonic antigen positivity in 71% and 76% of cases, respectively. Patients underwent surgery mostly for suspected malignancy; in 83% of cases, a standard pancreatic resection was performed. Mean SMC size was 4.9 (range, 1.5-12.0) cm. Mucins MUC5AC and MUC6 resulted positive in 77% and 81% of cases performed, respectively, whereas MUC2 was negative in all but one patient. The SMC from our institution was characterized by a KRAS somatic mutation. The diagnosis of SMC should be considered when a solitary pancreatic cyst larger than 1 cm is detected in asymptomatic patients. To establish a correct diagnosis, an extensive histologic/immunohistochemical analysis is essential. The presence of a KRAS mutation highlights that SMC may represent another potential pancreatic cancer precursor.

Keywords: Cystadenoma mucinous; Pancreas; Pancreatic cancer; Pancreatic cyst.

Publication types

  • Case Reports
  • Systematic Review

MeSH terms

  • Adult
  • Aged
  • Amylases / analysis
  • Biomarkers, Tumor / analysis*
  • Biomarkers, Tumor / genetics
  • Carcinoembryonic Antigen / analysis
  • Cystadenoma, Mucinous / genetics
  • Cystadenoma, Mucinous / metabolism
  • Cystadenoma, Mucinous / pathology*
  • Cystadenoma, Mucinous / surgery
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mucin 5AC / analysis*
  • Mucin-6 / analysis*
  • Mutation
  • Pancreatectomy
  • Pancreatic Cyst / chemistry
  • Pancreatic Cyst / genetics
  • Pancreatic Cyst / pathology*
  • Pancreatic Cyst / surgery
  • Pancreatic Intraductal Neoplasms / genetics
  • Pancreatic Intraductal Neoplasms / metabolism
  • Pancreatic Intraductal Neoplasms / pathology*
  • Pancreatic Intraductal Neoplasms / surgery
  • Pancreatic Neoplasms / chemistry
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / pathology*
  • Pancreatic Neoplasms / surgery
  • Precancerous Conditions / genetics
  • Precancerous Conditions / metabolism
  • Precancerous Conditions / pathology*
  • Precancerous Conditions / surgery
  • Proto-Oncogene Proteins p21(ras) / genetics


  • Biomarkers, Tumor
  • Carcinoembryonic Antigen
  • KRAS protein, human
  • MUC5AC protein, human
  • MUC6 protein, human
  • Mucin 5AC
  • Mucin-6
  • Amylases
  • Proto-Oncogene Proteins p21(ras)