Abstract:Objective: The aim of the present study was to evaluate diagnostic value of glycogen and mucin-staining features of aspirated cyst fluid, and carbonhydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA) levels in the blood and cyst fluid in differentiating benign from malignant lesions.Materials and Methods: A total of 13 patients, who were referred to the General Surgery Clinics due to pancreatic lesion between January 2013 and November 2013, were included in the study. In the preoperative period, CA 19-9 and CEA were obtained from all patients. The cyst fluid was aspirated in the guidance of radiological imaging methods in 6 methods and using laparoscopic or surgical methods in 7 patients. CA 19-9 and CEA levels were evaluated in the aspirated cyst fluids, and immunohistochemical tests were performed using PAS (glycogen) and mucin staining in patients with sufficient cyst fluid. The pancreatic tissue was macroscopically evaluated in patients who underwent an operation, and appropriate procedure was selected depending on the location of the lesion.Results: The pathological examination of the 13 patients revealed malignant lesion in 5, benign-inflammatory cyst (IC) in 5, serous cystic neoplasm (CSN) in 1, mucinous cystic neoplasm (MCN) in 1, and non-functional cystic neuroendocrine tumor (CNT) in 1. The blood tests performed in 5 patients with malignant findings on pathological examination revealed elevated CEA levels in 1 patient and elevated CA 19-9 levels in 3 patients. In the aspirated cyst fluids, CA 19-9 levels were high in 3 patients with malignant lesion and in patients with MCN and CNT. The immunohistochemical examination revealed positive staining for PAS and mucin in 2 patients with malignant lesion and one patient with MCN, and another patient with malignant lesion showed PAS-positive staining. Immunohistochemical examination involving PAS and mucin could not be performed in two patients one of which had malignant lesion due to insufficient aspiration fluid.Conclusion: In the present study, CA 19-9 levels in the blood and aspirated cyst fluids were found to be higher in patients with malignant pancreatic lesions. Of patients with malignant lesions, 3 showed positive PAS staining. However, long-term studies on larger series of patients are warranted in order to establish the diagnostic value of PAS-staining and mucin-staining in immunohistochemical examination of the cyst fluids and the value of CEA levels in the blood and aspirated cyst fluid.