Values of carcinoembryonic antigen, elastase 1, and carbohydrate antigen determinant in aspirated pancreatic cystic fluid in the diagnosis of cysts of the pancreas.

The levels of carcinoembryonic antigen (CEA), elastase 1, and carbohydrate antigen determinant (CA 19-9) in the pancreatic cystic fluid and the serum from five patients with cystadenocarcinoma of the pancreas, one patient with retention cyst due to pancreatic carcinoma, three patients with cystadenoma, and eight patients with benign pseudocyst accompanying or following pancreatitis, were determined by immunoassay technique. Fluid from pancreatic cysts was obtained by ultrasonically-guided percutaneous fine-needle aspiration biopsy. The specimens were centrifuged and the supernatant was used for the measurement of CEA, elastase 1, and CA 19-9, while the cell pellet was examined cytologically. The levels of CEA in the aspirated fluid were significantly higher in patients with malignant cysts of the pancreas than in those with benign cystadenomas and pseudocysts. In contrast, the levels of elastase 1 were significantly lower in patients with malignant cysts than in those with benign pancreatic cysts. Although the levels of CA 19-9 were significantly higher in patients with malignant cysts than in those with pseudocysts, the overlap between the values of patients with malignant and benign pancreatic cysts is too great. The serum CA 19-9 was most useful, however, to distinguish an individual patient with malignant cysts of the pancreas from those with benign pancreatic cyst, since there were no significant differences between the levels of serum CEA and elastase 1 in patients with malignant and benign pancreatic cysts. Correct diagnoses were made cytologically in 4 (66.7%) of 6 patients with malignant cysts. In two patients with malignant cyst, in whom no cancer cells were detectable in the aspirated materials, levels of CEA were abnormally high, but high levels of elastase 1 did not occur. Therefore, the combined measurement of CEA and elastase 1 in the aspirated cystic fluid of the pancreas could be used as an aid in diagnosis of malignant cysts of the pancreas.