A 77-year-old man was seen by his primary physician with the chief complaint of excessive weakness and fatigue. The man also appeared very pale. Suspecting anemia, the physician ordered a CBC.
The following are noteworthy results:
| Patient Results | Reference Range |
| WBC x 109/L | 2.6 | 4.5–10.5 |
| RBC x 1012/L | 2.55 | 4.7–6.1 |
| Hgb g/dL | 9.0 | 14–18 |
| Hct % | 26 | 42–52 |
| MCV fL | 111 | 80–100 |
| MCH. pg | 37.2 | 27–31 |
| MCHC g/dL | 33.6 | 32–36 |
| RDW % | 20.0 | 11.5–14.5 |
| Platelets x 109/L | 82 | 150–450 |
Notice that the patient has pancytopenia, which means all three cell lines are diminished: WBC, RBC, and platelets. Also, the MCV indicates macrocytosis.
The manual differential was even more informative.
