Pediatric Extramedullary Hematopoiesis

  • Etiology: response to long-standing anemia or extensive bone marrow replacement from myeloproliferative disorder
  • Imaging: mass-like expansion of hematopoietic tissue outside of bone marrow, common location is paravertebral in the posterior mediastinum, also see diffuse hepatomegaly + splenomegaly
  • Clinical: usually asymptomatic and incidentally detected

Radiology Cases of Extramedullary Hematopoiesis

CXR of extramedullary hematopoesis in thalassemia
CXR AP shows diffuse osteopenia of the bones, lobulated masses projecting over the posterior portions of the ribs bilaterally, and an expanded appearance of the anterior and posterior aspects of the ribs.