Are There Any Predictors to Differentiate Mucinous from Non-mucinous Pancreatic Cysts? A Single Center Experience

Abstract

Purpose: To study the differences in characteristics between mucinous and non-muncinous cysts of the pancreas as overlap in the characteristics of cyst fluid has been reported. Methods: 102 patients (41 males) patients who underwent EUS-FNA at a tertiary referral center from May 2002 to October 2008 were included in this analysis. Information regarding demographics, symptoms (abdominal pain, weight loss, jaundice), indication for EUS, findings on EUS, cytology results, cyst fluid analysis [carcinoembryonic antigen (CEA), amylase, lipase], CA 19-9 level, surgical pathology (if applicable), and history of diabetes mellitus (DM), alcohol, or smoking were obtained. Patients were categorized in the mucinous cyst group if cytology and/or surgical pathology confirmed the diagnosis. The above stated features were compared between the two groups (mucinous vs. non-mucinous). For statistical analysis, a two tailed unequal variance t-test was used for linear variables and χ2-test was used for categorical variables. A p<0.05 was used for statistical significance. Results: The most common indication for the procedure was evaluation of asymptomatic pancreatic cysts detected on transabdominal imaging modalities. The mean age of the patients in the cohort was 64 years (range: 23-87). Nineteen patients (19%) had mucinous cysts (2 IPMN's), 4 patients (4%) with mucinous cyst transformation to adenocarcinoma, and the rest were categorized as non-mucinous cysts (serous cysts, pseudocysts, simple benign cysts). There were no significant differences with regards to age (66 vs. 63 years, p=0.7), gender, symptoms, CA19-9 level (25 vs. 20 mcg/l, p=0.34), prevalence of DM, and use of tobacco and alcohol between the two groups. No significant differences in average cyst size (33mm vs. 30mm, p=0.5), number, location, presence of lobulation, or coexisting finding of chronic pancreatitis were noted. With regards to cyst fluid analysis, there was no difference in the mean CEA level (285 vs. 527 ng/ml, p=0.25) and mean amylase level (9263 vs. 13320 U/L, p=0.35) between the mucinous and non-mucinous groups. Conclusion: Results of this study did not identify any significant predictors for the presence of mucinous cysts in the evaluation of patients with pancreatic cysts. These results confirm previous reports of significant overlap in the characteristics of cyst fluid between different pancreatic cyst types.