Quick Cases in Haematology

Module summary

Abnormal full blood count results are often benign or transient, but may be early indicators of significant underlying pathology, including gastrointestinal disease, malignancy, nutritional deficiency or haematological disorders.

This case-based module explores five common but often challenging scenarios: unexplained iron deficiency, isolated macrocytosis, persistent thrombocytosis, functional iron deficiency in heart failure and iron deficiency without anaemia.

Learning objectives

This module will support you to:

• Apply a systematic approach to investigating iron deficiency anaemia (IDA) when initial gastrointestinal investigations are normal, including consideration of small bowel pathology, malabsorption and non-GI sources of blood loss.
• Identify and appropriately investigate causes of persistent macrocytosis in the presence of normal B12 and folate, including recognising when to suspect alcohol-related disease, endocrine disorders or early haematological malignancy.
• Differentiate between reactive and clonal thrombocytosis and carry out appropriate investigations, including malignancy screening and timely referral for suspected myeloproliferative neoplasms.
• Recognise functional iron deficiency in patients with heart failure and understand the role of intravenous iron therapy in improving symptoms and clinical outcomes, even in the absence of anaemia.
• Assess and manage iron deficiency without anaemia, including how to investigate and tailor management based on individual risk factors and clinical context.

Module reviewed by: Dr Keith Hopcroft, GP and Pulse clinical advisor

Date published: 23.04/2026