The value of standard serum tumor markers in differentiating mucinous from serous cystic tumors of the pancreas: CEA, Ca 19-9, Ca 125, Ca 15-3

Background: Differentiating between mucinous cystic tumors (MCTs) and serous cystic tumors (SCTs) can be a troubling diagnostic dilemma in pancreatology: when SCTs present in their macro-oligocystic form they must be resected because MCT cannot be ruled out, and some tumors considered benign are actually MCTs, which delays diagnosis and places patients at increased risk. Examination of preoperative serum tumor markers may help improve preoperative diagnosis. Materials and methods: The tumor markers CEA, Ca 19-9, Ca 125, and Ca 15-3 were examined in 157 patients with SCTs or MCTs. Results: Positive CEA marker status is an indicator of an MCT, although sensitivity is low at 17%. Using three serum tumor markers (CEA, Ca 19-9, and Ca 125), 27% of MCTs were found to have two or more markers positive, compared to none for the SCTs. Sensitivity decreases to 13% for differentiating benign MCTs from benign SCTs but specificity remains 100%. Conclusions: In the differential diagnosis of SCTs vs. MCTs no reliable serum tumor marker exists which can diagnose SCTs and spare some patients unnecessary operations. Nonetheless, positive CEA serum marker status and or the presence of more than two positive serum markers (CEA, Ca 19-9, or Ca 125) indicates the presence of an MCT and can prevent delay in diagnosis.