Evaluation of clinical parameters to distinguish mucinous cystic neoplasms from serous cystic neoplasms of pancreas - A retrospective study

Introduction: Pancreatic cystic neoplasms represent approximately 15% of all pancreatic tumours. Serous Cystic Neoplasm (SCN) is a benign lesion, and observation instead of surgical resection is suggested as first line treatment. Mucinous Cystic Neoplasm (MCN) has malignant potential and surgical resection has been considered the first line treatment. The preoperative distinction between SCN and MCN is important due to their completely different treatment strategies. Aim: This study was aimed to find clinical parameters for distinguishing between mucinous and serous cystic neoplasms of pancreas. Materials and Methods: From 1992 to 2010 at Chang Gung Memorial Hospital, Linkou, Taiwan and from 1988 to 2014 at Chang Gung Memorial Hospital, Keelung, Taiwan 141 patients underwent pancreatic tumour resection for pathologically proven SCN or MCN. The demographic data, characteristics and biochemistry data were reviewed and analysed. Results: In our study cohort, the levels of Aspartate Transaminase (AST) (p=0.009), Alanine Transaminase (ALT) (p=0.032), albumin (p=0.043) and Alkaline Phosphatase (ALP) (p<0.001) were all higher in the SCN group (p<0.001). Patients in the MCN group were noted to have relatively larger tumours (mean size of 8.11±4.72 cm vs. 6.05±3.58 cm, p=0.022). The SCNs were located predominantly in the head of the pancreas whereas the MCNs were predominantly located in the tail and body (p<0.001). After a logistic regression analysis, the independent factors that helped to distinguish SCN from benign MCN include the serum ALP level and the tumour location. We further applied a Receiver Operating Characteristic (ROC) curve to determine the cut-off value of ALP. The Area Under the Curve (AUC) for ALP was 0.762. The cut-off value for ALP was 61.5 U/L. We also found that when the ALP level was >61.5 U/L in the case of a proximally located pancreatic cystic neoplasm, SCN was indicated (84.2% specificity and 94.1% negative predictive value), but otherwise, MCN may be implicated. Conclusion: Preoperatively, SCN and benign MCN are not easily distinguishable from each other. However, a combination of the tumour location and the preoperative ALP level may provide some diagnostic benefit.