Predictors of malignant potential of cystic lesions of the pancreas

BackgroundCystic lesions of the pancreas (CLP) are a diagnostic dilemma, the correct characterisation of which determines surgical management.MethodsFrom 1995 to 2005, radiology and pathology records were reviewed for the presence of CLP. CLP were divided into three groups; Group 1: Benign, Group 2: Pre-malignant, and Group 3: Malignant.ResultsSeventy-nine of 121 patients were included [Group 1: n = 46, Group 2: n = 10, Group 3: n = 23], with a median age at diagnosis of 68 (31–92) years. The median follow-up period was 24 (14–84) months. On univariate analysis, female gender (p = 0.04), jaundice (p < 0.01), raised serum ALT concentration (p = 0.03), cyst size (≥2.5 cm) (p < 0.01), and biliary duct dilatation (p < 0.01) were associated with malignant potential. Benign cysts were more likely to present incidentally (p < 0.01). On multi-variate analysis, cyst size (≥2.5 cm) was an independent predictor of malignant potential. Sub-group analysis revealed that cysts < 2.5 cm in the head of the pancreas with evidence of biliary obstruction (either abnormal liver function; raised ALT [p = 0.01], ALP [p = 0.01], total bilirubin [p = 0.02], and/or biliary duct dilatation [p < 0.01]) were associated with malignant potential.ConclusionCyst size ≥2.5 cm on computer tomography imaging was an independent predictor of pre-malignant and malignant pancreatic cysts. Cyst size and the presence of biliary obstruction predict potentially malignant cysts of the head of the pancreas, which require surgical management.