Prevalence and Clinical Significance of Multiple Pancreatic Cysts

Abstract

Background: Diagnostic evaluation of pancreatic cysts may identify the presence of multiple cysts. We hypothesized that multiple pancreatic cysts are associated with branch duct type intraductal papillary mucinous neoplasia (IPMN), given the diffuse nature of the disease. Methods: A retrospective chart review was performed on consecutive patients who presented to a tertiary referral center from 2000-08 and underwent endoscopic ultrasound (EUS) for suspected pancreatic cysts. Cyst descriptions were gathered from EUS, CT, MRI/MRCP, surgical pathology, tumor marker, and cytology reports. All patients with more than one cyst on any imaging study were included in the multiple cyst category. Patients with non-cystic adenocarcinoma as well as those with known pseudocysts were excluded. The cysts were categorized as follows: 1) Definite IPMN: definite communication between the cyst and the pancreatic duct on any imaging or surgical pathology; 2) Not IPMN: when another definitive diagnosis was made, such as serous cystadenoma (SCA) based on CEA <20 ng/mL or pathology; mucinous cystic neoplasm (MCN) based on pathology; or other diagnoses on pathology such as neuroendocrine tumor, metastatic pancreatic lesions, or cystadenocarcinoma; 3) Possible IPMN: cysts of unknown status as well as those with CEA >192 ng/mL but no definitive communication described on imaging (uncategorized mucinous cysts). Cysts with CEA levels between 20 and 192ng/mL and without other identifying information were considered unknown. Results: A total of 145 patients met criteria for inclusion in the study. Forty-eight (33.1%) patients had more than 1 cyst detected in the pancreas. Of these 48 patients, 18 (37.5%) had IPMN, 8 (16.7%) SCA, 1 (2.1%) MCN, 3 (6.3%) uncategorized mucinous, 1 (2.1%) metastatic hypernephroma, and 17 (35.4%) unknown. The presence of multiple cysts on imaging was significantly associated with a diagnosis of IPMN compared to possible IPMN and not IPMN (chi square for trend, p = 0.0417). The calculated odds ratio for the presence of multiple cysts was 2.96 for definite IPMN vs. not IPMN (95% CI: 1.12, 8.07) and 2.43 for possible IPMN vs. not IPMN (95% CI: 1.05, 5.69). Conclusion: Multiple pancreatic cysts are seen in up to one-third of cases on pancreatic imaging. The presence of multiple cysts is suggestive of a diagnosis of IPMN. This association can help guide the management of patients with multiple cystic lesions of the pancreas.