This week’s case presented with a striking macrocytic anaemia on full blood count:

• Haemoglobin: 60 g/L
• MCV: 121.5 fL
• RBC: 1.44 ×10¹²/L
• Platelets: 240 ×10⁹/L

The cause of the macrocytosis was confirmed by the biochemistry results:

• Vitamin B12: 90 ng/L ↓
• Folate: Normal
• LDH: 1140 IU/L ↑

The peripheral blood film showed anisocytosis, polychromasia and oval macrocytes.

Together, the findings pointed toward a diagnosis of megaloblastic anaemia, in this case most likely due to vitamin B12 deficiency. The elevated LDH is consistent with ineffective erythropoiesis, a hallmark of this condition.

This case highlights the importance of recognising macrocytic patterns and pairing haematology testing and morphology with biochemical testing for timely diagnosis and management.