Multiple choice Which of the following diagnostic markers is for intestinal tumor? Alpha-fetoprotein Carcinoembryonic antigen The presence of Reed-Sternberg cells EBV-related antigens Common acute lymphoblastic leukemia antigen Reveal answer Fill a bubble to check yourself B Correct answer Explanation Carcinoembryonic antigen (CEA) is an oncofetal antigen but there is a high incidence of false positives. Reappearance of CEA after surgical removal of the primary tumor is strongly indicative of fresh tumor growth.