Primary Myelofibrosis Is the Most Frequent Myeloproliferative Neoplasm Associated With del(5q): Clinicopathologic Comparison of del(5q)-positive and -Negative Cases

Leuk Res. 2008 Dec;32(12):1927-30. doi: 10.1016/j.leukres.2008.04.022. Epub 2008 Jun 9.


Among 23 cases of myeloproliferative neoplasms (MPNs) with an associated del(5q) seen at our institution, 14 (61%) fulfilled diagnostic criteria for primary myelofibrosis (PMF). Other diagnoses included polycythemia vera (PV; n=2), essential thrombocythemia (ET; n=1), post-ET myelofibrosis (n=1), systemic mastocytosis (SM; n=1), and MPN, unclassifiable (n=4). Compared to their del(5q)-negative counterparts, del(5q)-positive PMF cases were significantly more anemic (p<0.001) and thrombocytopenic (p<0.001). However, survival and leukemic transformation rates appear to be similar between the two groups. del(5q)-positive PMF was histologically characterized by a mixture of both small and monolobated megakaryocytes as well as large and bizarre megakaryocytes. When used, lenalidomide therapy induced hematological and cytogenetic remissions in del(5q)-positive PMF. The current study identifies PMF as another del(5q)-associated myeloid malignancy with characteristic megakaryocyte morphology.

MeSH terms

  • Bone Marrow / pathology
  • Chromosomes, Human, Pair 5*
  • Humans
  • Megakaryocytes / pathology
  • Myeloproliferative Disorders / genetics*
  • Myeloproliferative Disorders / pathology
  • Primary Myelofibrosis / etiology
  • Primary Myelofibrosis / genetics*
  • Primary Myelofibrosis / mortality
  • Primary Myelofibrosis / pathology
  • Sequence Deletion*
  • Survival Analysis