Which anemia type is likely to occur with a normal MCV and decreased hemoglobin levels?

The correct answer is chronic disease anemia. This type of anemia is often associated with a normal mean corpuscular volume (MCV) while exhibiting decreased hemoglobin levels. Chronic disease anemia typically occurs in the context of chronic inflammatory states, infections, malignancies, or autoimmune diseases.

The underlying mechanism involves the sequestration of iron and the impaired production of red blood cells due to inflammatory cytokines. In chronic disease anemia, while the body produces erythrocytes, the effectiveness is reduced due to factors like reduced erythropoietin production or altered iron metabolism, leading to a scenario where hemoglobin levels drop without altering the size of the red blood cells, thus resulting in a normal MCV.

In contrast, ineffective erythropoiesis and aplastic anemia can lead to decreased hemoglobin but often present with distinct laboratory findings such as low to decreased MCV or changes in red blood cell morphology. Hemolytic anemia typically presents with signs of increased red cell destruction, leading to increased reticulocyte counts and often a decreased MCV due to early release of immature red cells.