Pediatric extramedullary hematopoiesis

Extramedullary hematopoiesis (ex·​tra·​med·​ul·​lary - he·​ma·​to·​poi·​e·​sis) occurs when blood cells from the bone marrow grow in other parts of the body. The Children’s Health℠ team includes top experts in treating the conditions that cause extramedullary hematopoiesis. Physicians at Children’s Health are on the faculty at UT Southwestern Medical Center and offer access to the latest, most effective treatments for these conditions.

What is pediatric extramedullary hematopoiesis?

In extramedullary hematopoiesis, the blood-forming cells that normally only exist in the bone marrow (medulla of the bone), form in other areas. The most common areas for this are the spleen or liver, but it can also occur in the skin, lungs, kidneys or other organs.

What are the signs and symptoms of pediatric extramedullary hematopoiesis?

  • Enlarged spleen
  • Enlarged liver
  • Nodules on the skin that often have a bluish tint

How is pediatric extramedullary hematopoiesis treated?

Extramedullary hematopoiesis is a symptom of three conditions (thalassemia, congenital dyserythropoietic anemia and sideroblastic anemia).

Treatments include:

Blood transfusions

Children who have severe forms of the conditions that cause extramedullary hematopoiesis need ongoing blood transfusions and careful monitoring. In this procedure, we give patients healthy blood from a donor. A red blood cell transfusion lasts between three and four hours and has to be repeated monthly. Blood transfusions turn off the body’s effort to make blood, which reverses the extramedullary hematopoiesis.


When a child's spleen is enlarged and causes difficulty with blood transfusions, a surgeon may need to remove it. Surgeons often use minimally invasive surgical techniques (laparoscopy) that cause less scarring and allow the child to recover faster.

Because the spleen is important in fighting some bacterial infections, your doctor will need to give additional vaccinations before removing the spleen. A child can have an active life without a spleen, but they will be at higher risk for infections.

Bone marrow transplant

A bone marrow transplant replaces your child’s diseased bone marrow with healthy, new cells from an appropriate donor. The bone marrow donor needs to be a close match to your child. The new bone marrow starts creating normal, healthy red blood cells.

Frequently Asked Questions

  • What is meant by pediatric extramedullary hematopoiesis?

    Pediatric extramedullary hematopoiesis occurs when blood cells form outside of the medulla (bone marrow).

  • Where does pediatric extramedullary hematopoiesis occur?

    Pediatric extramedullary hematopoiesisoccurs when blood cells from bone marrow grow in other areas of the body, including the spleen, liver, skin, lungs, kidneys or other organs.

  • Is extramedullary hematopoiesis cancerous?