Transudative Pleural Effusion Associated with Extramedullary Hematopoiesis

Intern Med. 2021 Feb 1;60(3):449-452. doi: 10.2169/internalmedicine.4668-20. Epub 2020 Sep 19.


The authors report a case of transudative pleural effusion associated with extramedullary hematopoiesis due to the presence of a myeloproliferative neoplasm, which was unclassified. A 71-year-old man presented with right pleural effusion during an exacerbation of thrombocytosis. The pleural effusion was transudative, although there was no history of cardiac failure or hypoalbuminemia, and treatment with diuretics failed. Extramedullary hematopoiesis was diagnosed in bilateral paravertebral soft tissue and the liver on 111In bone marrow scintigraphy. The administration of hydroxyurea simultaneously reduced peripheral blood platelet count and pleural effusion within 2 weeks. The possible cause of transudative pleural effusion in association with extramedullary hematopoiesis is discussed.

Keywords: bone marrow scintigraphy; hydroxyurea; myeloproliferative disorders; transudate.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Hematologic Diseases*
  • Hematopoiesis, Extramedullary*
  • Humans
  • Hydroxyurea
  • Male
  • Pleural Effusion* / diagnostic imaging
  • Pleural Effusion* / etiology
  • Primary Myelofibrosis* / complications
  • Primary Myelofibrosis* / diagnosis


  • Hydroxyurea