AFP and neoplasm: Serum tumor marker analysis demonstrated negative results for carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), and carbohydrate antigen 19-9 (CA19-9), with all values within normal reference ranges (CEA = 1.6 ng/mL, AFP = 4.98 ng/mL, CA19-9 = 20.7 U/mL).