A 64-year-old man has noted a 5 kg weight loss along with increasing fatigue over the past year. He has experienced dull abdominal pain for the past week. He has developed abdominal distention with lack of stools in the past two days. On physical examination, bowel sounds are reduced. An abdominal CT scan reveals a mass involving the descending colon. At laparotomy, a partial resection of the left colon is performed, with removal of an encircling mass in the descending colon. Microscopically, the mass is found to be a moderately differentiated adenocarcinoma.
Which of the following laboratory test findings is most likely to be present in this man?

A Microcytic hypochromic anemia

B Positive antinuclear antibody test

C Hyperglycemia

D Elevated alpha-fetoprotein

E Decreased lactate dehydrogenase

Answer / Explanation:

He has an adenocarcinoma of the colon. Such lesions are often associated with blood loss from mucosal erosion and necrosis.