An 18 year old patient’s hemogram shows Hb 12 g%, RBC count of 6 million, decreased MCV (56), decreased MCH (29) and RDW of 14. What is the most probable diagnosis?
**Core Concept**
Microcytic anemia is characterized by a decreased mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) with a normal or elevated red blood cell count. This type of anemia is often associated with iron deficiency, thalassemia, or chronic disease.
**Why the Correct Answer is Right**
The patient's hemogram shows a microcytic anemia with a decreased MCV (56 fl) and MCH (29 pg), indicating that the red blood cells are smaller than normal. The normal RBC count and increased red blood cell distribution width (RDW) suggest a heterogenous population of red blood cells, consistent with iron deficiency anemia or thalassemia. Iron deficiency anemia is the most common cause of microcytic anemia in adolescents and young adults.
**Why Each Wrong Option is Incorrect**
* **Option A:** While thalassemia can cause microcytic anemia, it typically presents with a more severe microcytosis and a normal or decreased RDW, making it less likely in this case.
* **Option B:** Sideroblastic anemia typically presents with a microcytic anemia, but it is often associated with an elevated RDW and a ringed sideroblast on iron staining, which is not mentioned in the patient's hemogram.
* **Option D:** Chronic disease anemia typically presents with a normocytic or macrocytic anemia, and is often associated with a low albumin level and a high erythrocyte sedimentation rate (ESR), which are not mentioned in the patient's hemogram.
**Clinical Pearl / High-Yield Fact**
In a patient with microcytic anemia, the presence of a normal or elevated RBC count and an increased RDW suggests iron deficiency anemia or thalassemia, whereas a decreased RBC count and a normal RDW suggest sideroblastic anemia.
**Correct Answer:** C. Iron deficiency anemia