Extramedullary haematopoiesis

Extramedullary haematopoiesis is a response to failure of erythropoiesis in the bone marrow.

Aetiology

Radiographic features

When involving an organ, extramedullary haematopoiesis causes visceromegaly occurring most often in the spleen (splenomegaly) and liver (hepatomegaly) and occasionally in the lymph nodes. Visceromegaly is best evaluated via ultrasound, CT or MRI.  Lesions are typically hypermetabolic and is FDG-18 avid on PET-CT.4

Extramedullary haematopoiesis less commonly affects the pleura, lungs, gastrointestinal tract, breast, skin, brain, kidneys, and adrenal glands.

However, in the less common situation where extramedullary haematopoiesis involves other tissues within the thorax, they can be seen as a posterior mediastinal mass. These paraspinal masses may be either unilateral or bilateral and have smooth, sharply delineated, often lobulated margins.

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Article information

rID: 12220
Synonyms or Alternate Spellings:
  • Extramedullary hematopoiesis
  • Extra-medullary haematopoiesis (EMH)
  • Extra-medullary haematopoiesis
  • Extramedullary haematopoiesis (EMH)
  • Extramedullary haemopoiesis
  • Extramedullary hemopoiesis

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Cases and figures

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    Case 1: in thalassemia
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    Case 1: in thalassemia
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    Case 2: in thalassaemia
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    CXR - PA
    Case 3: in thalassemia
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    Case 4
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    Red arrows:  extr...
    Case 5
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    Case 6
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    Case 7: in the adrenal gland
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