Cytology adds value to imaging studies for risk assessment of malignancy in pancreatic mucinous cysts

Ann Surg. 2011 Dec;254(6):977-83. doi: 10.1097/SLA.0b013e3182383118.


Objective: Evaluate the value of cytology relative to imaging features in risk assessment for malignancy as defined in the Sendai Guidelines.

Background: The Sendai Guidelines list symptoms, cyst size >30 mm, dilated main pancreatic duct (MPD) >6 mm, mural nodule (MN) and "positive" cytology as high risk stigmata for malignancy warranting surgical triage.

Methods: We reviewed clinical, radiological and cytological data of 112 patients with histologically confirmed mucinous cysts of the pancreas evaluated in a single tertiary medical center. Cytology slides were blindly re-reviewed and epithelial cells grouped as either benign or high-grade atypia (HGA) [≥high-grade dysplasia]. Histologically, neoplasms were grouped as benign (low-grade and moderate dysplasia) and malignant (in situ and invasive carcinoma). Performance characteristics of cytology relative to other risk factors were evaluated.

Results: Dilated MPD, MN, and HGA were independent predictors of malignancy (p < 0.0001), but not symptoms (p = 0.29) or cyst size >30 mm (p = 0.51). HGA was the most sensitive predictor of malignancy in all cysts (72%) and in small (≤30 mm) branch-duct intraductal papillary mucinous neoplasm (BD IPMN; 67%), whereas also being specific (85 and 88%, respectively). MN and dilated MPD were highly specific (>90%), but insensitive (39%-44%). Cytology detected 30% more cancers in small cysts than dilated MPD or MN and half of the cancers without either of these high-risk imaging features.

Conclusions: Cytology adds value to the radiological assessment of predicting malignancy in mucinous cysts, particularly in small BD IPMN.

MeSH terms

  • Adenocarcinoma, Mucinous / pathology*
  • Aged
  • Biopsy, Fine-Needle
  • Carcinoma in Situ / pathology
  • Carcinoma, Pancreatic Ductal / pathology*
  • Cell Transformation, Neoplastic / pathology
  • Cohort Studies
  • Cystadenocarcinoma, Mucinous / pathology*
  • Diagnosis, Differential
  • Endosonography
  • Female
  • Guideline Adherence
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Neoplasm Invasiveness
  • Pancreatic Cyst / pathology*
  • Pancreatic Ducts / pathology
  • Pancreatic Neoplasms / pathology*
  • Risk Assessment
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed
  • Ultrasonography, Interventional