Evaluation of cyst fluid CEA analysis in the diagnosis of mucinous cysts of the pancreas

Abstract

Background: Although cyst fluid carcinoembryonic antigen (CEA; > 192 ng/ml) is the preferred test for identifying mucinous pancreatic cysts, the data are more robust for mucinous cystic neoplasms (MCN) than for intraductal papillary mucinous neoplasms (IPMN). The role of cyst fluid CEA as a marker for either malignancy or malignant progression is uncertain.

Methods: All patients with pancreatic cysts who had undergone endoscopic ultrasound with cyst fluid CEA measurement between 2001 and 2009 were identified. Patient outcomes and pathology from operative resections were recorded.

Results: Two hundred sixty-seven patients were identified; pathological diagnosis was obtained in 97. Mucinous cysts were identified in 66 of 97 (68%): benign IPMN, n = 42; malignant IPMN, n = 10; benign MCN, n = 12; malignant MCN, n = 2. CEA > 192 ng/mL had a sensitivity and specificity of 73% and 65% for identifying mucinous cysts; cyst fluid CEA was not associated with malignancy (p = 0.85). One hundred seventy-eight patients were managed with an initial non-operative strategy. Eight (4%) developed radiographic changes necessitating surgery; pathology demonstrated seven benign mucinous cysts and one retention cyst. CEA was not associated with radiographic progression (p = 0.37).

Conclusions: Cyst fluid CEA is a useful test for identifying mucinous cysts, including MCN and IPMN. In mucinous cysts, cyst fluid CEA is not associated with malignancy or radiographic progression.