Myelofibrosis
Overview
Plain-Language Overview
Myelofibrosis is a rare blood disorder that affects the bone marrow, the soft tissue inside bones where blood cells are made. In this condition, the bone marrow becomes scarred and unable to produce enough healthy blood cells, leading to problems like anemia, fatigue, and increased risk of infections or bleeding. The body tries to compensate by producing blood cells in other organs such as the spleen and liver, causing these organs to enlarge. Symptoms often include night sweats, weight loss, and abdominal discomfort due to the enlarged spleen. This disease primarily impacts the blood and immune system, affecting overall health and quality of life.
Clinical Definition
Myelofibrosis is a chronic myeloproliferative neoplasm characterized by bone marrow fibrosis, ineffective hematopoiesis, and extramedullary hematopoiesis. It is commonly caused by mutations in genes such as JAK2, CALR, or MPL, leading to constitutive activation of the JAK-STAT pathway. The hallmark pathological feature is progressive fibrosis of the bone marrow due to abnormal proliferation of megakaryocytes and release of fibrogenic cytokines. Clinically, it presents with splenomegaly, anemia, and constitutional symptoms like fever and weight loss. The disease can progress to acute leukemia and is associated with significant morbidity and mortality. Diagnosis and management require integration of clinical, laboratory, and molecular findings.