Differential Diagnosis for Elevated MCV, MCH, and Normal RDW
- Single most likely diagnosis
- Macrocytic Anemia: This is the most likely diagnosis given the elevated Mean Corpuscular Volume (MCV) and Mean Corpuscular Hemoglobin (MCH) with a normal Red Cell Distribution Width (RDW). Macrocytic anemia can be caused by various factors including vitamin B12 or folate deficiency, which are common and well-known causes of this type of anemia.
- Other Likely diagnoses
- Vitamin B12 or Folate Deficiency: These deficiencies can lead to macrocytic anemia, characterized by elevated MCV and MCH. A normal RDW suggests a relatively uniform population of red blood cells, which can be seen in these deficiencies.
- Alcohol-Related Anemia: Chronic alcohol consumption can lead to macrocytosis (elevated MCV) due to the toxic effects of alcohol on bone marrow and the potential for associated nutritional deficiencies.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Myeloproliferative Neoplasms (e.g., Polycythemia Vera): Although less common, myeloproliferative neoplasms can present with macrocytosis. These conditions can have significant morbidity and mortality if not diagnosed and treated appropriately.
- Hypothyroidism: Severe, untreated hypothyroidism can lead to macrocytic anemia. While not as common as other causes, missing this diagnosis could lead to significant morbidity.
- Rare diagnoses
- Ornithine Transcarbamylase Deficiency: A rare genetic disorder that can lead to macrocytic anemia due to the accumulation of carbamoyl phosphate, which interferes with pyrimidine synthesis.
- Lesch-Nyhan Syndrome: Another rare genetic disorder that can result in macrocytic anemia, though it is more commonly associated with other systemic manifestations.
- Certain Medications: Some medications, such as those used in chemotherapy, can induce macrocytosis as a side effect. While not a disease per se, recognizing drug-induced causes is crucial for management.