The serum tumor marker test showed slightly elevated carbohydrate antigen 72–4 and neuron-specific enolase levels at 7.18 U/mL (reference range, < 6.5 U/mL) and 16.21 ng/mL (reference range, < 15 ng/mL), respectively, but normal levels of all other tumor markers, including alpha-fetoprotein, carcinoembryonic antigen, carbohydrate antigen 15–3, carbohydrate antigen 19–9, cancer antigen 125, and total prostate-specific antigen. Here, CEACAM5 is linked to neoplasm.