Myelodysplastic/myeloproliferative neoplasm

Myelodysplastic/Myeloproliferative Neoplasms (MDS/MPN) are a group of rare hematological disorders that exhibit both myelodysplastic and myeloproliferative features. These diseases are characterized by ineffective hematopoiesis, which leads to a variety of cytopenias, and by the overproduction of one or more types of blood cells.

Classification

The World Health Organization (WHO) classifies MDS/MPN into four subtypes:

• Chronic Myelomonocytic Leukemia (CMML)
• Juvenile Myelomonocytic Leukemia (JMML)
• Atypical Chronic Myeloid Leukemia (aCML)
• MDS/MPN with Ring Sideroblasts and Thrombocytosis (MDS/MPN-RS-T)

Each subtype has distinct clinical and pathological features, and they are all considered separate diseases.

Pathophysiology

The pathophysiology of MDS/MPN is complex and not fully understood. It is believed to involve a combination of genetic mutations, epigenetic changes, and alterations in the bone marrow microenvironment. Commonly mutated genes in MDS/MPN include RAS, JAK2, and FLT3.

Diagnosis

Diagnosis of MDS/MPN is based on clinical features, blood counts, bone marrow examination, and genetic testing. The WHO has established specific diagnostic criteria for each subtype of MDS/MPN.

Treatment

Treatment of MDS/MPN is largely supportive and includes blood transfusions, growth factor therapy, and targeted therapies for specific genetic mutations. In some cases, stem cell transplantation may be considered.

Prognosis

The prognosis of MDS/MPN varies widely depending on the subtype and the individual patient's characteristics. In general, these diseases are associated with a poor prognosis and a high risk of transformation to acute myeloid leukemia (AML).

See also

• Myelodysplastic syndromes
• Myeloproliferative neoplasms
• Leukemia