Difference between revisions of "Bone marrow"
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*'''Cellularity''': In patients 20-80 years, the percentage should be about 100 minus age, such as 40% in a 60 year old patient. | *'''Cellularity''': In patients 20-80 years, the percentage should be about 100 minus age, such as 40% in a 60 year old patient. | ||
*'''Thrombopoiesis''': There are normally about 3 megakaryocytes per 40x field. | *'''Thrombopoiesis''': There are normally about 3 megakaryocytes per 40x field. | ||
| − | *'''Myeloid/erythroid ratio''', usually defined as the ratio between the number of neutrophil granulocytes and precursors versus the number of erythroblasts. Depending on source, the lower limit of the normal range for this ratio bone marrow aspirate smears in adults is 1 to 2, and the upper limit is 5 to 8.<ref name=Medicalkey>{{cite web|title=Chapter 5: Pathology of the marrow|url=https://basicmedicalkey.com/pathology-of-the-marrow-general-considerations-and-infectionsreactive-conditions/|website=Basicmedical Key|author=BJ. Bain|date=2017-02-19}}</ref> In histologic sections, the normal range is 1.5 – 3.0.<ref name=Medicalkey/> Some hematologists also include eosinophils, basophils and monocytes, as well as their precursors, in the myeloid number, but this has only a minor effect on the M:E ratio in normal individuals.<ref name=Medicalkey/> | + | *'''Myeloid/erythroid ratio''', usually defined as the ratio between the number of neutrophil granulocytes and precursors versus the number of erythroblasts. Depending on source, the lower limit of the normal range for this ratio bone marrow aspirate smears in adults is 1 to 2, and the upper limit is 5 to 8.<ref name=Medicalkey>{{cite web|title=Chapter 5: Pathology of the marrow|url=https://basicmedicalkey.com/pathology-of-the-marrow-general-considerations-and-infectionsreactive-conditions/|website=Basicmedical Key|author=BJ. Bain|date=2017-02-19}}</ref> In histologic sections, the normal range is 1.5 – 3.0.<ref name=Medicalkey/> Some hematologists also include eosinophils, basophils and monocytes, as well as their precursors, in the myeloid number, but this has only a minor effect on the M:E ratio in normal individuals.<ref name=Medicalkey/> Still, if you are to calculate the value for a senior, check their preference first. |
*Look for any '''granuloma''' or '''cancer metastasis''' | *Look for any '''granuloma''' or '''cancer metastasis''' | ||
Revision as of 09:25, 5 January 2022
Author:
Mikael Häggström [note 1]
Contents
Autopsy
Microscopic evaluation
- Confirm trilineage hematopoiesis (see image).
- Look for apparent cellular atypia or decrease of cellular diversity.
Report
Example in a normal case:
| Bone marrow from rib (or other location if applicable): Trilineage hematopoiesis. There is no evidence of malignancy. |
Bone marrow aspirate
Perform a differential count by counting 500 cells[1] and dividing the numbers by 5 to get their percentages. Don't count cells that don't have a cytoplasm or nucleus.
Bone marrow biopsy
Evaluate the following:
- Adequacy: There should preferably be 5 intertrabecular spaces.
- Cellularity: In patients 20-80 years, the percentage should be about 100 minus age, such as 40% in a 60 year old patient.
- Thrombopoiesis: There are normally about 3 megakaryocytes per 40x field.
- Myeloid/erythroid ratio, usually defined as the ratio between the number of neutrophil granulocytes and precursors versus the number of erythroblasts. Depending on source, the lower limit of the normal range for this ratio bone marrow aspirate smears in adults is 1 to 2, and the upper limit is 5 to 8.[2] In histologic sections, the normal range is 1.5 – 3.0.[2] Some hematologists also include eosinophils, basophils and monocytes, as well as their precursors, in the myeloid number, but this has only a minor effect on the M:E ratio in normal individuals.[2] Still, if you are to calculate the value for a senior, check their preference first.
- Look for any granuloma or cancer metastasis
In a bone marrow count, nucleated red blood cells count into the total percentage of cells (but does not count into percentage of white blood cells in peripheral blood).
See also
Notes
- ↑ For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
Main page
References
- ↑ Abdulrahman AA, Patel KH, Yang T, Koch DD, Sivers SM, Smith GH (2018). "Is a 500-Cell Count Necessary for Bone Marrow Differentials?: A Proposed Analytical Method for Validating a Lower Cutoff. ". Am J Clin Pathol 150 (1): 84-91. doi:. PMID 29757362. Archived from the original. .
- ↑ 2.0 2.1 2.2 BJ. Bain (2017-02-19). Chapter 5: Pathology of the marrow. Basicmedical Key.
Image sources
