Bone marrow nonneoplastic


Mast cells

Topic Completed: 1 August 2012

Minor changes: 1 September 2021

Copyright: 2002-2021,, Inc.

PubMed Search: Bone marrow mast cells [title]

Dragos C. Luca, M.D.
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Cite this page: Luca DC. Mast cells. website. Accessed December 3rd, 2021.
Definition / general
  • Part of the immune system; functionally and structurally closely related to basophils but current evidence indicates that immediate precursors are different
  • Arise from same progenitor cell population as neutrophils, eosinophils, basophils and monocytes (CD34+, c-kit+, CD13+)
  • Production driven by stem cell factor (c-kit ligand), thrombopoietin, FLT3 ligand and IL6
  • Mast cells leave bone marrow and circulate in immature form, mature at tissue site (basophils mature in bone marrow)
  • Play a central role in allergic reactions through IgE receptor mediated responses; granules are rich in histamine and heparin
  • Also have protective role in wound healing, defense against pathogens
  • Stem cell factor is crucial for their development, proliferation and maturation (Immunol Res 2006;34:97)
Microscopic (histologic) description
  • Rare in normal marrow, usually concentrated within particles on aspirate smears and perivascular on biopsy sections
  • Larger (up to 100%) than basophils with irregular, elongated spindle shapes and cytoplasmic extensions
  • Cytoplasm is packed with basophilic granules that may obscure nuclear margin; nucleus is round and single (lobated in basophils)
Microscopic (histologic) images

AFIP images

Mast cells

Images hosted on other servers:

Mast cells

Spindle mast cell

Mast cells in kidney (various images)

Purple (metachromatic) granules with toluidine blue

Positive stains
Negative stains
Electron microscopy images

Images hosted on other servers:

Various images

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