Myelodysplasia

Question 1

Define myelodysplasia

Answer 1

A group of haematological disorders caused by defects in stem cells -> progressive bone
marrow failure and cytopenia -> secondary AML

Question 2

What are the causes/risk factors of myelodysplasia?

Answer 2

Premature apoptosis -> hypercellular bone marrow and peripheral cytopenia
Primary (80%)
Secondary (20%)
• Chemotherapy
• Radiotherapy

Risk Factors
• Chromosomal abnormalities (partial or total loss of 5, 7, 20, Y)
• Chemotherapy
• Radiotherapy

Question 3

What are the symptoms of myelodysplasia?

Answer 3

• Asymptomatic (50%)

Anaemia
• Fatigue/reduced exercise tolerance
• Dizziness

Neutropenia
• Recurrent infections

Thrombocytopenia
• Easy bruising
• Epistaxis

Question 4

What are the signs of myelodysplasia?

Answer 4

Anaemia
• Pallor
• Cardiac flow murmur

Neutropenia
• Recurrent infections

Thrombocytopenia
• Purpura/petechiae
• Ecchymoses

Question 5

What investigations are carried out for myelodysplasia?

Answer 5

• FBC - Pancytopaenia • Blood Film - normocytic or macrocytic red cells. Ovalomacrocytosis. Variable microcytic red cells in RARS. Reduced or absent granulocytes with reduced granulation and bilobed (‘Pelgeroid’) nucleus. Raised monocytes (CMML). Raised myeloblasts.
• Bone Marrow Biopsy - hypercellularity, ringed sideroblasts (haemosiderin deposits in the mitochondria of erythroid precursors form an apparent ring around the nucleus) with dyserythropoietic features, abnormal granulocyte precursors and megakaryocytes. 10 % show marrow fibrosis.