Myelofibrosis, idiopathic

A rare bone marrow disorder

Idiopathic Myelofibrosis
Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Fatigue, anemia, splenomegaly
Complications	Transformation to acute leukemia
Onset	Typically in adults over 50
Duration	Chronic
Types	N/A
Causes	Unknown
Risks	Age, genetic mutations
Diagnosis	Blood tests, bone marrow biopsy
Differential diagnosis	N/A
Prevention	N/A
Treatment	Symptomatic management, bone marrow transplant
Medication	N/A
Prognosis	Variable
Frequency	Rare
Deaths	N/A

Idiopathic Myelofibrosis (IMF) is a rare hematological disorder characterized by the replacement of bone marrow with fibrous tissue, leading to anemia, splenomegaly, and other systemic symptoms. It is classified as a type of myeloproliferative neoplasm (MPN).

Pathophysiology

Idiopathic Myelofibrosis is marked by the proliferation of abnormal hematopoietic stem cells in the bone marrow, which leads to the deposition of fibrous connective tissue. This fibrosis disrupts normal blood cell production, resulting in pancytopenia and extramedullary hematopoiesis, often manifesting as splenomegaly. The exact cause of IMF is unknown, but it is associated with mutations in the JAK2, CALR, and MPL genes.

Clinical Presentation

Patients with IMF often present with symptoms related to anemia, such as fatigue and weakness. Splenomegaly can cause abdominal discomfort and early satiety. Other symptoms may include night sweats, weight loss, and bone pain. The disease can progress to acute myeloid leukemia in some cases.

Diagnosis

The diagnosis of IMF is based on clinical findings, blood tests, and bone marrow biopsy. Blood tests typically show anemia, leukocytosis, or thrombocytosis. A bone marrow biopsy reveals fibrosis and atypical megakaryocytes. Molecular testing for JAK2, CALR, and MPL mutations can aid in diagnosis.

Treatment

Treatment of IMF is primarily supportive and aimed at managing symptoms. Options include blood transfusions for anemia, hydroxyurea to control high blood counts, and ruxolitinib, a JAK1/2 inhibitor, to reduce splenomegaly and systemic symptoms. In eligible patients, allogeneic stem cell transplantation may offer a potential cure.

Prognosis

The prognosis of IMF varies widely. Some patients may live for many years with minimal symptoms, while others may experience rapid disease progression. The development of acute leukemia is a significant risk factor for poor outcomes.

Also see

• Myeloproliferative neoplasm
• Polycythemia vera
• Essential thrombocythemia
• Acute myeloid leukemia