This week’s case explored a blood film from a patient with known multiple myeloma, now presenting with progressive symptoms and worsening cytopenias.

The blood film showed:

• Numerous plasma cells
• Some rouleaux formation
• Normocytic anaemia
• Cytopenias in other lineages

These features, particularly the presence of circulating plasma cells, are unusual in early stages of myeloma but may be seen in advanced or refractory disease. The mild rouleaux formation correlates with the elevated paraprotein levels and increased serum viscosity often associated with plasma cell disorders. he patient presented with symptoms suggestive of multiple myeloma, such as fatigue, bone pain, and signs of anaemia. These helped guide the interpretation of the film.

Given the limited clinical details and only mild rouleaux, it could be difficult to distinguish this from plasma cell leukaemia on morphology alone. One helpful differentiator is an elevated total protein level, often markedly raised in multiple myeloma.

This case highlights the importance of recognising when a typical multiple myeloma picture shifts into more aggressive behaviour, potentially overlapping with plasma cell leukaemia. Morphology remains a key tool in tracking disease progression and guiding further investigations.