Understanding Splenomegaly and Splenectomy in Myelofibrosis

Myelofibrosis (MF) is a type of blood cancer that belongs to the group of myeloproliferative neoplasms (MPNs). MF can affect the spleen, making it grow larger, a condition called splenomegaly. 

An enlarged spleen can affect your daily life. It can press on other organs and cause discomfort with simple movements like bending or walking. Many people also experience reduced appetite because the stomach has less room to expand. An enlarged spleen can also increase the need for blood transfusions. 

What is splenomegaly in myelofibrosis?

Splenomegaly is the word doctors use to describe an enlarged spleen. Around nine out of ten patients with MF will have splenomegaly. This is because blood cell production shifts from the bone marrow to the spleen. This process is called extramedullary hematopoiesis, meaning blood cells are made outside the bone marrow.

The enlargement can range from a few centimeters below the ribs on the left side to very large dimensions. A swollen spleen can cause a variety of symptoms. These include: 

• Abdominal (belly) pain
• Early fullness when eating
• Weight loss
• Fatigue
• Low blood counts
• Portal hypertension, which is increased pressure in the vein that connects the intestines and liver
• Splenic infarction, which is loss of blood supply to part of the spleen

What is a splenectomy and why would it be done for people with MF? 

A splenectomy is the surgical removal of the spleen. In MF, this option is usually reserved for people with severe symptoms or complications that cannot be controlled with medications. These may include:

• Abdominal pain or discomfort that does not go away
• Severe portal hypertension
• Very low platelet counts (thrombocytopenia)
• Frequent transfusion requirements for anemia

A type of medication called a JAK1/2 can shrink the spleen and reduce symptoms in many patients. However, some patients do not respond or lose their response over time. For those patients, splenectomy is a possible next step.

What are the risks of splenectomy?

Splenectomy is not a routine procedure in MF because it carries significant risks.  Approximately 17% to 30% of people with myelofibrosis with massive splenomegaly for whom JAK inhibitors have stopped working may need a splenectomy, with other indications including severe anemia or painful splenomegaly.

Splenectomy requires general anesthesia and carries significant risks as any surgery does. The recovery time varies but is typically at least two weeks. Complications of splenectomy can include:

• Bleeding (seen in about 14% of cases)
• Blood clots (13%)
• Infections (9%)
• Perioperative mortality (death around the time of surgery, about 8% to 9% in large studies)

There are also long-term side effects of splenectomy. It is important to be aware of them, so you canc all your care team if you notice any changes. These include: 

• Reactive thrombocytosis (platelet counts rising too high)
• clotting and bleeding problems
• Acceleration of disease transformation to acute myeloid leukemia (AML)

How does splenectomy affect MF outcomes?

Some studies show that splenectomy can improve anemia, reduce the need for transfusions, and relieve pressure symptoms. Median survival after splenectomy has ranged from about 19 months to over 2 years in different studies, but outcomes depend on the person’s condition before surgery. Lower platelet counts before surgery have been linked to shorter survival.

Splenectomy before stem cell transplant

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only potentially curative treatment for MF. Whether splenectomy should be done before transplant is debated. Talk to your doctor about your options. 

• Potential benefit: smaller spleen size may help with faster blood count recovery after transplant.

• Risks: the surgery itself adds significant complications and does not always improve transplant outcomes.

Currently, splenectomy before HSCT is not routine. It may be considered in patients with massive splenomegaly who are at high risk of graft failure, but decisions are made on a case-by-case basis.

Are there alternatives to splenectomy?

For patients who are not good candidates for surgery, splenic irradiation can be used to shrink the spleen and ease symptoms. This involves directing radiation at the spleen over several sessions. While it can temporarily improve pain and decrease spleen size, its effects usually last only a few months, and it can cause low blood counts to worsen.

Learning about the treatment options for splenomegaly

Splenomegaly is a central feature of advanced myelofibrosis and can lead to major symptoms that affect quality of life. While splenectomy may provide relief, it carries significant risks and is generally reserved for patients whose disease no longer responds to medications. The decision to undergo splenectomy, especially before stem cell transplant, requires careful discussion with your care team.

Keep exploring more articles on the HealthTree News site to learn more and connect with others living with myelofibrosis.

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Sources: 

• Splenectomy in Myelofibrosis: Indications, Efficacy, and Complications
• Understanding Splenomegaly in Myelofibrosis: Association with Molecular Pathogenesis
• Outcome of Splenectomy in JAK2 Inhibitor Treated Patients With Myelofibrosis