A selective approach to the resection of cystic lesions of the pancreas: results from 539 consecutive patients

Abstract

Objective: To define a group of patients with pancreatic cysts who do not require resection.

Summary background data: The increased use of cross-sectional imaging has resulted in an increased identification of small, asymptomatic pancreatic cysts. Data have not been available to determine which lesions should be resected.

Methods: All patients evaluated at our institution between January 1995 and January 2005 for the ICD-9 diagnosis of pancreatic cyst were reviewed. Analysis was performed to identify associations between patient and cyst characteristics, and selection of operative or nonoperative management.

Results: Pancreatic cysts were evaluated in 539 patients. Initial management was operative in 170 patients (32%), and nonoperative (radiographic follow-up) in 369 patients (68%). Factors associated with initial operative management included presence of a solid component (45% vs. 6%, P < 0.001), larger size of the lesion (mean 4.8 cm vs. 2.4 cm, P = 0.001), and presence of symptoms (44% vs. 16%, P = 0.001). Malignancy was present in 18% (32 of 170) of patients initially resected. Mucinous tumors (n = 18) were the most common malignant histologic subtype. None of the invasive cancers arising from mucinous cysts was <3 cm. Median radiographic follow-up in patients initially managed nonoperatively was 24 months (range, 1-172 months). In 29 patients (8%), changes developed within the cyst that resulted in resection; malignancy was present in 11 of 39 (38%), representing 3% (11 of 369) of all patients being followed radiographically.

Conclusions: Selected patients with cystic lesions <3 cm in diameter and without a solid component may be followed radiographically with a malignancy risk (3% this study) that approximates the risk of mortality from resection. Malignancy within mucinous tumors is associated with size, and small mucinous tumors are very unlikely to be malignant.

FIGURE 1. The number of patients evaluated (A), mean cyst diameter (B), and percentage of patients with symptomatic lesions (C) over the 10-year time period of the study.

FIGURE 2. Decision tree analysis for the selection of initial operative management in the 539 patients evaluated for a pancreatic cyst.

FIGURE 3. Change in cyst diameter over time in patients with serous or mucinous cysts of the pancreas (confirmed by fine needle aspiration, resection, or cyst fluid analysis).

FIGURE 4. The presence of benign, in situ, and invasive disease in patients who underwent resection for a mucinous cystic tumor of the pancreas.

FIGURE 5. Representative cross section of patient with a cystic lesion initially followed radiographically (A) who 22 months later developed changes adjacent to the cyst (B) found to be adenocarcinoma at the time of resection.