OBJECTIVE(S): Increased use of high-quality cross-sectional imaging has resulted in increased identification of small, asymptomatic pancreatic cysts. Data is not available to determine which lesions should be resected.
METHODS: Patients evaluated between Jan.1995 and Jan.2005 for the ICD-9 diagnosis of pancreatic cyst were reviewed. Patient, cyst, and management characteristics were recorded. Analyses were performed to identify associations between patient, and cyst characteristics, and selection of operative and non-operative management.
RESULTS: Pancreatic cysts were evaluated in 539 patients. Initial management was operative in 169 patients (31%), and non-operative in 370 patients (69%). Factors associated with operative management included increased cyst diameter (mean 4.8cm. vs. 2.4cm, p=0.001), presence of solid component (45% vs. 6%, p<0.001), and presence of symptoms (44% vs. 16%, p=0.001). Malignancy was present in 19% (32/169) of patients initially resected. Mucinous tumors (papillary mucinous carcinoma,n=12; mucinous cystadenocarcinoma,n=6) were the most common malignant sub-types. All patients with invasive mucinous tumors had lesions >3cm in diameter (see figure). Median radiographic follow-up for patients initially managed non-operatively was 24 months. Radiographic changes prompting subsequent resection occurred in 30 patients (8%) . Malignancy was present in eight of these patients (8/30, 27%), and represents 2% of patients (8/340) being followed radiographically.
CONCLUSIONS: Selected patients with cystic lesions <3cm in diameter and without a solid component may be followed with a malignancy risk (2% this study) that approximates the risk of mortality from resection. Malignancy within mucinous cysts is associated with size, and small mucinous tumors may be followed safely in selected patients.