Which myeloproliferative disorder benefits from splenectomy due to extramedullary hematopoiesis?

Myelofibrosis is a myeloproliferative disorder characterized by the replacement of bone marrow with fibrous tissue, leading to decreased hematopoiesis within the marrow. As a consequence, the body often compensates by increasing extramedullary hematopoiesis, which typically occurs in the spleen and liver. This can lead to significant splenomegaly and associated symptoms, including discomfort and pain due to the enlarged spleen.

Splenectomy is beneficial in myelofibrosis because removing the spleen can alleviate symptoms related to splenomegaly, improve blood counts by reducing the excessive destruction of blood cells in the enlarged spleen, and, in some cases, restore hematopoiesis back to the bone marrow where it is meant to primarily occur. The removal of the spleen can also help manage complications associated with hypersplenism, such as thrombocytopenia or anemia.

In contrast, while conditions like polycythemia vera and essential thrombocythemia can involve splenomegaly, they do not primarily benefit from splenectomy due to extramedullary hematopoiesis. Chronic myeloid leukemia also does not typically involve extramedullary hematopoiesis as