A 45-year-old man is found to have Hb 7.2 g/dL, MCV 68 fL. Serum iron 8 µmol/L, TIBC 72 µmol/L (elevated), serum ferritin 6 ng/mL. He has no overt GI bleeding, melena or haematuria. Which investigation is mandatory as the next step in a middle-aged male with unexplained iron deficiency anaemia?

• A Bone marrow aspiration to quantify iron stores
• B Check haemoglobin electrophoresis to exclude thalassaemia trait
• C Bidirectional endoscopy (upper GI endoscopy and colonoscopy) to exclude GI malignancy ✓
• D Start IV iron infusion and reassess in 3 months

Explanation

Iron deficiency anaemia in a middle-aged male (or any post-menopausal woman) without an obvious dietary cause is considered GI malignancy until proven otherwise. Bidirectional endoscopy (simultaneous upper GI endoscopy and colonoscopy) is mandatory, as colorectal and gastric cancers are common causes of occult GI blood loss presenting as IDA. A haemoglobin electrophoresis is relevant for diagnosing thalassaemia trait (which shows normal ferritin), not IDA. Treating with iron without investigation risks missing a curable malignancy.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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