**Core Concept**
Pelger-Huet anomaly is a benign, inherited condition characterized by the presence of hypo-segmented neutrophils in the peripheral blood. It is a result of a mutation in the gene encoding the CEBPA transcription factor, which plays a crucial role in the regulation of myeloid cell development.

**Why the Correct Answer is Right**
In individuals with Pelger-Huet anomaly, there is an abnormality in the process of myeloid cell maturation. This leads to the production of neutrophils with fewer nuclear segments than normal. The nucleus of affected neutrophils typically appears as a single large lobed mass with 1-3 nuclear segments, rather than the usual 3-5 segments. This anomaly is often associated with a mild increase in the number of immature neutrophils and monocytes in the blood.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because Pelger-Huet anomaly is not associated with a decrease in the number of neutrophils, but rather an abnormality in their nuclear segmentation.
* **Option B:** This option is incorrect because Pelger-Huet anomaly is not a result of a viral infection, but rather a genetic mutation.
* **Option C:** This option is incorrect because Pelger-Huet anomaly is not a form of leukemia, but rather a benign condition.

**Clinical Pearl / High-Yield Fact**
Pelger-Huet anomaly can be a diagnostic challenge, as the presence of hypo-segmented neutrophils can mimic other conditions such as myeloid leukemia. However, the absence of other abnormal findings, such as anemia, thrombocytopenia, or blasts, and a normal bone marrow examination, can help differentiate it from more serious conditions.

**Correct Answer:** D. Hypo-segmented neutrophils