In an asymptomatic elderly man with hypochromic, microcytic anemia, which diagnostic tests would be appropriate?

In the context of an asymptomatic elderly man with hypochromic, microcytic anemia, the appropriate diagnostic tests should focus on identifying possible causes of iron deficiency anemia, which is the most likely diagnosis given the description of the anemia.

Conducting a fecal occult blood test and sigmoidoscopy is essential in this scenario because these tests help identify potential gastrointestinal bleeding, which is a common cause of iron deficiency anemia, particularly in older adults. Chronic blood loss from the gastrointestinal tract could result from conditions such as adenomatous polyps, colorectal cancer, or peptic ulcers, all of which could lead to the observed anemic state.

Complete blood count and reticulocyte count, while useful, do not directly address the specific cause of microcytic anemia. Serum iron studies and bone marrow biopsy could provide additional insights but are not the first steps when addressing potential gastrointestinal bleeding. Cytogenetic analysis and serum B12 levels are not relevant to this case, as they pertain more to different types of anemia or conditions that do not match the presented clinical picture.

Thus, testing for occult blood and performing sigmoidoscopy is the most targeted approach to rule out treatable causes in this man’s demographic, making it the most appropriate choice.