Under what circumstances can extramedullary hematopoiesis occur?

Extramedullary hematopoiesis (EMH) occurs under various circumstances, including during embryonic/developmental periods, pathological status secondary to insufficient bone marrow function or ineffective hematopoiesis, in hematological disorders, for example malignancies, as well as stromal disorders of the bone.

What is dog extramedullary hematopoiesis?

Extramedullary hematopoiesis (EMH) is the formation and development of blood cells outside the bone marrow, and in dogs it frequently occurs in the spleen. Although splenic EMH is a relatively common condition, data regarding its appearance in veterinary medicine are lacking.

Is extramedullary hematopoiesis cancerous?

Extramedullary hematopoiesis (EMH) usually occurs in hematological disease, but more rarely develops in cases of malignant solid tumors.

When does physiologic extramedullary hematopoiesis occur?

Extramedullary hematopoiesis in fetus is a physiological process which consists of two steps: (1) primitive hematopoiesis which develops in yolk sack during 2.5–8 weeks of fetal life as a temporary red cell forming system, and (2) definitive hematopoiesis which is developed later to generate the entire blood cells and …

How do you confirm extramedullary hematopoiesis?

Fine-needle biopsy can confirm the diagnosis. Extramedullary hematopoiesis occurs as a compensatory mechanism for abnormal hematopoiesis when normal red marrow is unable to function because of deficiency disorders or because of various pluripotent stem cell disorders.

How is extramedullary hematopoiesis treated?

Treatment of such cases is usually done with blood transfusions, which can reduce the hematopoietic drive for EMH. Other options include surgery, hydroxyurea, radiotherapy, or a combination of these on a case to case basis.

How is extramedullary hematopoiesis diagnosed?

What causes extramedullary hematopoiesis in dogs?

Conditions associated with extramedullary hematopoiesis include acute and chronic hemolytic anemia, myeloproliferative disorders, and lymphoproliferative disorders (Fig. 4-18D). Appearing similar to extramedullary hematopoiesis is myelolipoma, an uncommon tumor in both dogs and cats, occurring in the liver or spleen.

What is the meaning of hematopoiesis?

Hematopoiesis: The production of all types of blood cells including formation, development, and differentiation of blood cells. Prenatally, hematopoiesis occurs in the yolk sack, then in the liver, and lastly in the bone marrow.

What happens during hematopoiesis?

Hematopoiesis is the production of all of the cellular components of blood and blood plasma. It occurs within the hematopoietic system, which includes organs and tissues such as the bone marrow, liver, and spleen. Simply, hematopoiesis is the process through which the body manufactures blood cells.

What does it mean to have extramedullary hematopoiesis?

Micrograph showing nucleated red blood cells (bottom left of image), one of the elements necessary to call extramedullary hematopoiesis, in an endometrial polyp. H&E stain. Extramedullary hematopoiesis ( EMH or sometimes EH) refers to hematopoiesis occurring outside of the medulla of the bone ( bone marrow ). It can be physiologic or pathologic.

Who is the 52 year old woman with extramedullary hematopoiesis?

Cite this page: Jain S. Extramedullary hematopoiesis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/livertumorEMH.html. Accessed June 14th, 2021. 52 year old woman with 2.5 cm, 5 cm and 7 cm liver masses and normal serum AFP ( Arch Pathol Lab Med 2003;127:631 )

Can a dog have LH and extramedullary hematopoiesis?

Extramedullary hematopoiesis (EMH), lymphoid hyperplasia (LH), and amyloidosis can cause diffuse changes and gen­eralized splenomegaly. Extramedullary hematopoiesis and lymphoid hyperplasia are often diagnosed from the same spleen, in both dogs and cats.

What is extramedullary haematopoiesis in the spleen?

Extramedullary haematopoiesis is a response to the failure of erythropoiesis in the bone marrow. This article aims to a general approach on the condition, for a dedicated discussion for a particularly involved organ, please refer to the specific articles on: extramedullary haematopoiesis in the spleen.