HIGH HE4 CYSTIC FLUID/SERUM RATIO: A PREDICTOR OF MALIGNANCY IN PANCREATIC CYSTIC LESION? A CASE REPORT.

Pancreatic cystic lesions are discovered frequently on modern imaging, posing a clinical problem because they might lead to ductal adenocarcinoma. The evaluation of cystic fluid carcinoembryonic antigen (CEA) concentration and cytology have low sensitivity in distinguishing mucinous from non-mucinous cysts. Recently, some authors reported that circulating HE4 (Human epididymis protein 4) levels were higher in subjects with pancreatic adenocarcinoma than in the controls. We reported here the observation of elevated HE4 levels in pancreatic cyst fluid of malignant origin encountered in our laboratory medicine practice. The sample showed high HE4 cyst fluid levels and low serum HE4 values. The high fluid/serum ratio value in this patient was associated with malignant lesion. Interestingly, the same patient showed high CEA cyst fluid/serum ratio. This patient had mucinous cystadenomas and developed lung and liver metastasis in less than 3 years, Both HE4 and CEA cystic fluid/serum ratios are high. This preliminary observation suggested the need to perform further studies on large population to assess whether cystic fluid/serum ratio of HE4, as well as CEA, might perform as cancer-specific biomarker for pancreatic cystic lesions.