Pediatric myelofibrosis: WHO 2024 update on myeloproliferative neoplasms calling?

Pediatr Blood Cancer. 2020 May;67(5):e28232. doi: 10.1002/pbc.28232. Epub 2020 Mar 5.

Abstract

Objectives: Pediatric myelofibrosis is a rare entity with the largest reported series of 19 cases. We describe here the clinicopathological spectrum and outcomes of 15 cases of pediatric myelofibrosis.

Methods: Case files of myelofibrosis of patients less than 18 years were retrieved from January 2016 to January 2019, and patients with idiopathic myelofibrosis after exhaustive work-up were studied. Their clinicopathological profiles were studied and then followed up for resolution and malignant transformation.

Results: Of the 15 cases of idiopathic myelofibrosis, transfusion-dependent anemia (14/15) was most common presentation. Only one patient showed leukoerythroblastosis with dacryocytes. Myeloid hyperplasia was seen in 13 of 15 patients and megakaryocytic hyperplasia in 10 patients. Dysmegakaryopoiesis was seen in 8 of 15 patients, and only three had small loose megakaryocytic clustering. None showed hyperchromatic megakaryocytes, intrasinusoidal hematopoiesis, or osteosclerosis. One patient with trisomy 8 tested positive for JAK2V617F. Bone marrow biopsy was hypercellular in 13, and 8 had world health organization (WHO) MF-3 fibrosis. None of the patients developed malignancy, one had spontaneous resolution, and one patient required allogenic stem cell transplant.

Conclusions: Pediatric myelofibrosis is a distinct entity from primary myelofibrosis in adults and merits mention in the WHO manual as a distinct entity.

Keywords: anemia; dysmegakaryopoiesis; idiopathic myelofibrosis; pediatric myelofibrosis.

MeSH terms

  • Adolescent
  • Adult
  • Amino Acid Substitution
  • Cell Transformation, Neoplastic* / genetics
  • Cell Transformation, Neoplastic* / metabolism
  • Cell Transformation, Neoplastic* / pathology
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Janus Kinase 2* / genetics
  • Janus Kinase 2* / metabolism
  • Male
  • Megakaryocytes / metabolism
  • Megakaryocytes / pathology
  • Mutation, Missense*
  • Neoplasm Proteins* / genetics
  • Neoplasm Proteins* / metabolism
  • Osteosclerosis / genetics
  • Osteosclerosis / metabolism
  • Osteosclerosis / pathology
  • Primary Myelofibrosis / genetics
  • Primary Myelofibrosis / metabolism
  • Primary Myelofibrosis / pathology
  • Retrospective Studies
  • Thrombopoiesis*

Substances

  • Neoplasm Proteins
  • JAK2 protein, human
  • Janus Kinase 2