CEACAM5 and neoplasm: Elevated tumor markers were infrequently observed in SPN, with 5.6% showing increased levels of neuron specific enolase (NSE), followed by carcinoembryonic antigen (CEA) (2.2%), carbohydrate antigen 19-9 (CA 19-9) (1.1%), and alpha fetoprotein (AFP) (0.5%).