Bone marrow

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Revision as of 14:50, 16 December 2021 by Mikael Häggström (talk | contribs) (Cells)
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Author: Mikael Häggström [note 1]

Bone marrow aspirate showing normal "trilineage hematopoiesis":
- Myelomonocytic cells: an eosinophil myelocyte marked
- Erythroid cells: an orthochromatic erythroblast marked
- Megakaryocytic cells.

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, normally 3-4 myeloid cells per erythroid cell.
  • 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).

Notes

  1. 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

  1. 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:10.1093/ajcp/aqy034. PMID 29757362. Archived from the original. . 

Image sources