> For the complete documentation index, see [llms.txt](https://docs.celly.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.celly.ai/supported-tests/bone-marrow-wbc-differential.md).

# Bone marrow: WBC differential

**Bone marrow (BM) aspiration examination** refers to the pathologic analysis of bone marrow samples. Bone marrow examination is used in the diagnosis of a number of conditions, including leukemia, multiple myeloma, lymphoma, anemia, and pancytopenia. 

![Bone marrow smear](/files/-MJZ1irLwRnxjtrAtDWw)

The test performing is similar to [**Blood: WBC differential**](/supported-tests/blood-wbc-differential.md), however, there are the following differences:

* App Settings: **Cells To Analyse for BM = 500** (Blood = 100)
* Result review -> Cells: For the BM test **the list of cell types is wider**, includes: Blast, Prolymphocyte, Lymphocyte, Plasma Cell, Promonocyte, Monocyte, Promyelocyte, Myelocyte, Metamyelocyte, Eosinophil, Basophil, Band Neutrophil, Segmented Neutrophil, Proerythroblast, Basophilic Erythroblast, Polychromatic Erythroblast, Orthochromatic Erythroblast, Megakaryocyte.
* Result review -> Report: For the BM test the system automatically calculates main indexes - **M:E, I:Mg**, and **I:Me ratio**.

![Report example](/files/-MJZ6NwY1M22Vg9_oz6Q)

{% hint style="info" %}
M:**E** - Number of myeloid cells/Number of nucleated erythroid cells

**I:Mg** - (Number of myeloblasts + promyelocytes + myelocytes + metamyelocytes)/(Number bands + segmented)

**I:Me** - Number of proerythroblasts + basophilic erythroblasts/Number of polychromatic and orthochromatic erythroblasts
{% endhint %}