Figure 26 Differential diagnosis of macrocytic anemia.

ALT, Alanine transaminase; AST, aspartate aminotransferase; MCV, mean corpuscular volume; RBC, red blood cell; R/O, rule out; TSH, thyroid-stimulating hormone.

Modified and updated from Rakel RE [ed]: Principles of family practice, ed 7, Philadelphia, 2007, Saunders.