Leukoerythroblastic Reaction

**Semantic type:** Laboratory or Test Result

**Definition:** A laboratory test result indicating the presence of nucleated red blood cells and immature leukocytes in the peripheral blood. It is observed in disorders causing extramedullary hematopoiesis such as myelofibrosis and metastatic cancer to the bone marrow.

**Synonyms:** - Leukoerythroblastosis