EXPRESSION OF CA-72-4 (TAG-72) IN THE FLUID CONTENTS OF PANCREATIC CYSTS - A NEW MARKER TO DISTINGUISH MALIGNANT PANCREATIC CYSTIC TUMORS FROM BENIGN NEOPLASMS AND PSEUDOCYSTS

Objective The authors evaluated cyst fluid CA 72-4 as a tumor marker i n the differential diagnosis of pancreatic cystic lesions. Summary Bac kground Data Pancreatic cystic lesions include inflammatory pseudocyst s, serous cystadenomas, and mucinous tumors. Mucinous tumors can be fu rther subdivided into mucinous cystadenocarcinomas and premalignant mu cinous cystic neoplasms. The clinical and radiologic features of these lesions are unreliable to make a preoperative diagnosis of these diag nostically difficult lesions.Analysis of aspirated cyst fluid was Prop osed as an aid to making the preoperative differential diagnosis. Curr ently, a number of parameters have been reported as useful markers in cyst fluid aspirates, including the tumor markers carcinoembryonic ant igen and CA 15.3, enzymes (amylase, lipase, and amylase isoenzymes), r elative viscosity, and cytologic analysis. However, owing to the rarit y of pancreatic cystic tumors, experience with cyst fluid analysis is limited. To define additional markers that might be useful in the diff erential diagnosis of pancreatic cysts, the authors measured the tumor -associated glycoprotein 72 (TAG-72) in aspirates from 19 pancreatic c ystic lesions. Methods Cyst fluid from 19 pancreatic cysts was obtaine d by needle aspiration. The tumor marker TAG72 was measured by a comme rcial (CA 72-4) immunoassay. Results Cyst fluid CA 72-4 levels in muci nous cystadenocarcinomas were markedly elevated (mean, 10,027 U/mL; ra nge, 780 to 34,853 U/mL) compared with that in pseudocysts (mean, 3.8 U/mL; range, < 3 to 5.7 U/mL) and serous cystadenomas (mean and range, < 3 U/mL; p < 0.001). The level of CA 72-4 in benign mucinous cystic neoplasms was intermediate (mean, 44.2 U/mL; range, < 3 to 137 U/mL), but it was statistically different from either carcinomas (p = 0.009) or benign cysts (p < 0.001). Conclusions CA 72-4 in cyst fluid aspirat es is a promising new marker for the differentiation of mucinous cysta denocarcinoma from pseudocysts, serous cystadenomas, and mucinous cyst ic neoplasms. Intermediate values are associated with benign mucinous cystic neoplasms.