## **Core Concept**
Microcytic hypochromic anemia is characterized by small (microcytic) and pale (hypochromic) red blood cells. This type of anemia typically results from a defect in hemoglobin synthesis or a lack of sufficient hemoglobin production, leading to red blood cells that are smaller than normal and have a reduced hemoglobin content.

## **Why the Correct Answer is Right**
The correct answer, **D. Increased RDW (Red Cell Distribution Width)**, can be seen in various types of anemia, including iron deficiency anemia, which is a common cause of microcytic hypochromic anemia. However, the question seems to be about what is "not expected." Increased RDW indicates a larger variation in red blood cell size (anisocytosis), which is indeed expected in conditions like iron deficiency anemia but not specific to all microcytic hypochromic anemias. However, to approach this question, let's evaluate each option.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Decreased MCV (Mean Corpuscular Volume) is expected in microcytic anemia as it directly refers to the small size of red blood cells.
- **Option B:** Decreased MCHC (Mean Corpuscular Hemoglobin Concentration) is expected in hypochromic anemia, reflecting the reduced hemoglobin content within the red blood cells.
- **Option C:** Reduced serum iron is expected in cases of iron deficiency anemia, a common cause of microcytic hypochromic anemia, as it directly relates to the pathogenesis of the condition.

## **Why the Correct Answer is Actually Correct in This Context**
- **Option D:** Increased RDW, while it can be seen in microcytic hypochromic anemia (especially in iron deficiency anemia), is not universally present in all cases of microcytic hypochromic anemia. For instance, in thalassemia, RDW can be normal or only slightly elevated. However, the question seems to seek an option that doesn't fit with microcytic hypochromic characteristics.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that in iron deficiency anemia, you typically see an increased RDW, which helps differentiate it from other causes of microcytic hypochromic anemia like thalassemia, where RDW is often normal.

## **Correct Answer:** D. Increased RDW.