Extramedullary haematopoiesis (EMH) is a response to erythropoiesis failure in bone marrow. EMH occurs in haemoglobinopathies, myeloproliferative disorders, or bone marrow infiltration. EMH occurs most often in the spleen and liver and occasionally in the lymph nodes. Less common organs include the pleura, lungs, gastrointestinal tract, breast, skin, brain, kidneys, and adrenal glands.
- myeloproliferative disorders
Where EMH involves an organ, there is usually radiographic evidence of its enlargement, e.g. hepatomegaly, splenomegaly visualised by ultrasound, CT or MRI. However, in the less common situation where EMH involves other tissues within the thorax, they can be seen as a posterior mediastinal mass. These are paraspinal masses that may be unilateral or bilateral and have smooth, sharply delineated, often lobulated margins.
- 1. Choi H, David CL, Katz RL et-al. Case 69: extramedullary hematopoiesis. Radiology. 2004;231 (1): 52-6. doi:10.1148/radiol.2311020673 - Pubmed citation
- 2. Gumbs RV, Higginbotham-ford EA, Teal JS et-al. Thoracic extramedullary hematopoiesis in sickle-cell disease. AJR Am J Roentgenol. 1987;149 (5): 889-93. AJR Am J Roentgenol (abstract) - Pubmed citation
- 3. Holden C, Hennessy O, Lee WK. Diffuse mesenteric extramedullary hematopoiesis with ascites: sonography, CT, and MRI findings. AJR Am J Roentgenol. 2006;186 (2): 507-9. doi:10.2214/AJR.04.1788 - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Extra-medullary haematopoiesis (EMH)||✗|
|Extramedullary haematopoiesis (EMH)||✗|