Polycythemia

Virginia C. Broudy, MD

University of Washington School of Medicine, Seattle, WA

This case was reviewed and updated in August 2013 by Dr. Eric Kraut and members of the Teaching Cases Subcommittee.

Copyright of the American Society of Hematology, 2006. ISSN: 1931-6860.

V. PATHOPHYSIOLOGY

Click here to review the categories of polycythemia.

Polycythemia vera is a neoplastic disorder that originates in a hematopoietic stem cell.

Stem Cell Model of Hematopoiesis

Stem cells reconstitute hematopoiesis when transplanted into a myeloablated host.
Progenitor cells expand in the presence of growth factors and can be identified by their ability to form colonies in vitro.
Precursor cells are morphologically recognizable cells seen in the marrow aspirate.
Mature cells circulate in the blood.

Quiescent cells periodically divide, and one daughter cell returns to the Go (quiescent) state, while the other becomes committed to differentiation to a progenitor cell. With each division, the progenitor cells become progressively restricted to fewer hematopoietic lineages. Finally, morphologically recognizable precursor cells mature to produce circulating blood cells.

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