Myelodysplasia

Question 1

Define Myelodysplasia

Answer 1

Series of haematological conditions characterised by chronic cytopenias due to ineffective and dysplastic haematopoeiesis (anaemia, neutropenia, thrombocytopenia) and abnormal cellular maturation

Blasts = 0-20%

Question 2

Aetiology of Myelodysplasia

Answer 2

Primary Chromosomal abnormalities (40-70%), most commonly deletion of tumour suppressor genes

Secondary to radiotherapy or chemotherapy

Question 3

Risk factors for Myelodysplasia

Answer 3

Age >70
Long-term DNA alkylating agent use e.g. chlorambucil, cyclophosphamide
Therapy with topoisomerase inhibitors
Prior haematopoietic stem cell transplantation
Environmental exposure to tobacco, benzene
Congenital neutropenia e.g. Kostmann’s, Shwachman-Diamond’s syndrome, Down’s syndrome (trisomy 21)
Fanconi anaemia
Ataxia telengiectasia
Bloom’s syndrome
Xeroderma pigmentosum
Mutagen-detoxification
Aplastic anaemia

Question 4

Epidemiology of Myelodyspasia

Answer 4

Mean age 65-75
Secondary myelodysplasia is seen more commonly in younger adults
Male more common
2x more common than AML

Question 5

Symptoms of Myelodysplasia

Answer 5

Asymptomatic (found on lab findings)

Anaemia: Fatigue, Exercise intolerance, Pallor
Thrombocytopenia: petechiae, purpura, bleeding
Neutropenia: recurrent infections

Question 6

Signs of Myelodyspasia

Answer 6

Gum hypertrophy
Lymphadenopathy

Spleen does NOT tend to be enlarged

Question 7

Investigations for Myelodysplasia

Answer 7

Bone marrow trephine biopsy: Hypercellular ringed sideroblasts (haemosiderin deposits in the mitochondria) | abnormal granulocyte precursors | megakaryocytes | marrow fibrosis

FBC: Pancytopenia
Blood film: Raised granulocytes + absent granulation + bi-lobed Pelgeroid nucleus | Monocytes raised | myeloblasts | ovalmacrocytosis