Bone marrow aspirate: generalised increase in iron stores Faecal occult blood: negative

An 84-year-old man was referred for investigation of anaemia. He had been feeling weak and lethargic.
His past medical history included diverticular disease and duodenal ulcer.
Investigations showed:
Hb 7.2 g/dl 130-180
WBC 4.8 x 109
/l 4-11
Platelets 182 x 109/l 150-400
MCV 112 fl 80-96
Iron 32 µmol/l 12-30
TIBC 70 µmol/l 45-75
Serum folate 24nmol/l 2-11
Serum B12 270 pmol/l 160-760
TSH 3.4 mU/l 0.4-5.0
LDH 200 U/l 10-250
Blood film: dimorphic picture
Bone marrow aspirate: generalised increase in iron stores
Faecal occult blood: negative.
Which of the following is the correct diagnosis?

A. Gastrointestinal blood loss
B. Haemolytic anaemia
C. Iron deficiency anaemia
D. Megaloblastic anaemia
E. Sideroblastic anaemia (Correct)

Sideroblastic anaemia is a condition in which the bone marrow produces atypical nucleated erythroblasts with
granules of iron accumulated in the perinuclear membrane (sideroblasts). There is inability of iron utilisation,
resulting in disordered haem synthesis and hence microcytic hypochromic cells and diamorphic blood film.
Sideroblastic anaemia is most often associated with myelodysplastic syndromes, but can also be inherited. In
addition, can occur in other bone marrow conditions including myeloma, polycythaemia rubra vera and
leukaemia. Secondary causes include rheumatoid arthritis, SLE, chronic infections and hypothyroidism.
Clinical features are those related to anaemia (and or cytopenia). Diagnosis requires bone marrow
examination, which shows ring sideroblasts and increased iron stores. Full blood count shows anaemia, with a
normal or increased MCV. Serum iron and transferrin saturation are usually high, and the blood film shows a
dimorphic population of normal and hypochromic red blood cells. Total iron binding capacity is usually normal.
Treatment is in general supportive, or of the underlying condition. Transfusion can be considered, with care to
avoid iron overload.
Megaloblastic anaemia is a broad term, often caused by vitamin B12 or folate deficiency. Blood film shows
macrocytes with hypersegmented polymorphs.
Options A and C are unlikely because of normal serum iron and total iron-binding capacity (TIBC) and negative
faecal occult blood.