How can I differentiate between MDS and other causes of cytopenias in a primary care context?

Differentiating between myelodysplastic syndromes (MDS) and other causes of cytopenias in a primary care setting primarily involves recognizing suspicious features and ruling out more common, benign causes before considering referral for specialist investigation ²,⁴. MDS is a group of clonal disorders of haematopoietic stem cells characterized by ineffective haematopoiesis and peripheral cytopenias, which can affect one or more cell lines (anaemia, neutropenia, thrombocytopenia) (Foran and Shammo, 2012).

In primary care, the initial step for unexplained cytopenias is to perform a full blood count (FBC) ²,⁴. Key indicators that may raise suspicion for MDS or other haematological cancers include:

• Persistent unexplained cytopenias affecting one or more cell lines, such as anaemia, neutropenia, or thrombocytopenia ²,⁴. MDS often presents with anaemia, but can also involve isolated neutropenia or thrombocytopenia, or a combination (Foran and Shammo, 2012).
• Abnormal white cell count, particularly unexplained neutropenia ²,⁴.
• Unexplained bruising or bleeding, which could indicate thrombocytopenia ²,⁴.
• Persistent unexplained fatigue, a common symptom of anaemia ²,⁴.
• The presence of other systemic symptoms like unexplained weight loss, fever, night sweats, or lymphadenopathy, although these are less specific to MDS and can indicate other haematological malignancies ²,⁴.
• Splenomegaly, which may be present in some cases of MDS, though it is more common in other myeloproliferative neoplasms (Foran and Shammo, 2012).

Before considering referral for suspected MDS, it is important to investigate and exclude other common causes of cytopenias, which include:

• Nutritional deficiencies (e.g., vitamin B12 or folate deficiency) ¹,⁴.
• Drug-induced cytopenias ¹,⁴.
• Chronic diseases (e.g., chronic kidney disease, liver disease, inflammatory conditions) ¹,⁴.
• Infections ¹,⁴.
• Autoimmune conditions ¹,⁴.

If, after initial investigations, the cytopenias remain unexplained or there are features suggestive of a haematological malignancy, the patient should be referred for a suspected cancer pathway, typically to a haematologist ²,⁴. Definitive diagnosis of MDS requires a bone marrow examination, which is performed in secondary care (Foran and Shammo, 2012).