An 80‐year‐old woman is brought to the physician’s office accompanied by a friend. The
patient reports severe fatigue, loss of weight and appetite, and a burning sensation in her feet. She lives alone and has one meal a day delivered by a local food bank. The friend was visiting and noticed the woman had some memory deficits and appeared very fatigued. Review of systems is remarkable for trouble sleeping and urinary incontinence. Examination reveals not only diminished memory and concentration, but an ataxic gait and diminished vibratory sensation in her lower extremities. A complete blood count shows:
Hemoglobin 8.8 g/dL
Leukocyte count 4600/mm3
Mean corpuscular hemoglobin 128 µm3
Platelets 220,000/mm3
A blood smear most likely will reveal which of the following hematologic abnormalities?
- A. Dark blue, coarse cytoplasmic granules in the cytoplasm of neutrophils
- B. Giant cytoplasmic granules within the cytoplasm of neutrophils
- C. Multilobed neutrophil nuclei with five or more segments
- D. Occasional neutrophils with bilobed nuclei and reduced granulation
0 voters
The correct answer is C. This patient’s macrocytic anemia is likely due to a vitamin B12 deficiency, which can also explain her abnormal neurologic examination. In addition to a macrocytosis and anemia, the lack of vitamin B12 results in abnormal development of the nucleus. Hypersegmented neutrophils, although not pathognomonic for B12 or folate deficiency, is highly suggestive of these conditions. Of note, the neurologic abnormalities seen in this patient is seen in B12, but not folate deficiency.
Dark blue, coarse cytoplasmic granules (choice A), or toxic granulations, are seen in
any systemic illness. There is no reason to suspect this woman has a major infection
that would result in prominent toxic granulations.
Giant cytoplasmic granules (choice B), if associated with recurrent infections in an
infant, may indicate a congenital neutrophil disorder, such as Chediak‐Higashi
syndrome. Giant granules are not a feature of B12 deficiency.
Bilobed nuclei (choice D) connected by a thin strand of nucleus and often with reduced
or absent cytoplasmic granulations suggest either a congenital disorder (Pelger‐Huet
anomaly) or myelodysplastic syndrome.