MCV of 90 fL: Clinical Significance
An MCV of 90 fL is within the normal range (80-100 fL) and does not indicate a red blood cell size abnormality in adults. 1
Normal Range Context
- The normal MCV range for adults is 80-100 fL, making 90 fL a mid-range normal value 1
- This value indicates normocytic red blood cells, meaning the cells are of normal size 1
- No further investigation of MCV is warranted based on this value alone unless other hematologic abnormalities are present 1
Clinical Interpretation Framework
When MCV is normal (80-100 fL), focus shifts to other complete blood count parameters to identify potential pathology:
- If anemia is present with normal MCV, consider normocytic causes including hemorrhage, hemolysis, bone marrow failure, anemia of chronic inflammation, or renal insufficiency 1
- Reticulocyte count becomes the critical next test to distinguish between decreased red blood cell production versus increased destruction or loss 1
- Peripheral blood smear examination should be performed when evaluating any anemia, even with normal MCV, to confirm red blood cell morphology 1
Important Considerations
- Inflammation can influence MCV values, so interpret this result in the context of inflammatory markers like C-reactive protein 1
- Combined deficiencies may mask abnormal MCV: A patient with concurrent iron deficiency (which lowers MCV) and vitamin B12 deficiency (which raises MCV) may present with a falsely normal MCV 1
- Medication effects should be considered, as certain drugs can alter MCV independent of nutritional status 1
Common Pitfalls to Avoid
- Do not assume normal MCV excludes all hematologic pathology—normocytic anemias are clinically significant 1
- Do not rely solely on MCV for anemia classification without evaluating hemoglobin, red blood cell count, and other indices 1
- Do not overlook the possibility of mixed deficiencies that artificially normalize the MCV 1