Adult with progressive pallor, hyper-segmented neutrophils and MCV>100 shows?
**Core Concept**
The patient's presentation of progressive pallor, hyper-segmented neutrophils, and a high Mean Corpuscular Volume (MCV) suggests a megaloblastic anemia, which is caused by impaired DNA synthesis due to a deficiency in either vitamin B12 or folate.
**Why the Correct Answer is Right**
The presence of hyper-segmented neutrophils is a hallmark of megaloblastic anemia, indicating that the bone marrow is producing immature white blood cells. This is because megaloblastic anemia results from the inhibition of DNA synthesis, leading to the production of large, immature cells. The high MCV is also consistent with megaloblastic anemia, as the cells are larger than normal due to impaired DNA synthesis. The progressive pallor is likely due to the anemia itself, which reduces the amount of hemoglobin in the blood.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not explain the presence of hyper-segmented neutrophils and high MCV. A low MCV would be more consistent with iron deficiency anemia.
**Option B:** This option is incorrect because it does not address the underlying cause of the megaloblastic anemia. A high MCV can be seen in other conditions such as iron deficiency anemia, but the presence of hyper-segmented neutrophils and progressive pallor points towards megaloblastic anemia.
**Option C:** This option is incorrect because it does not explain the specific findings of hyper-segmented neutrophils and high MCV. A low platelet count can be seen in megaloblastic anemia, but it is not the primary finding.
**Clinical Pearl / High-Yield Fact**
Megaloblastic anemia should be considered in any patient with a high MCV and hyper-segmented neutrophils, as it is a red flag for a deficiency in either vitamin B12 or folate. This is a classic exam trap, as it is easy to confuse megaloblastic anemia with iron deficiency anemia, but the presence of hyper-segmented neutrophils and high MCV should raise suspicion for megaloblastic anemia.
**Correct Answer:** D. Megaloblastic anemia.