Barbara J. Bain is Professor of Diagnostic Haematology in the Centre for Haematology, Department of Immunology and Inflammation, Imperial College London, UK, and Honorary Consultant Haematologist, Imperial College NHS Trust, St Mary’s Hospital, London. David M. Clark is a Consultant Haematopathologist at the Haematological Malignancy Diagnostic Service, Nottingham University Hospitals NHS Trust and Honorary Clinical Senior Lecturer, Department of Medicine, Imperial College London. Bridget S. Wilkins is a Consultant Haematopathologist at Guy’s and St Thomas’ Hospital NHS Foundation Trust, London and Hampshire Hospitals NHS Foundation Trust, Winchester, as well as Honorary Clinical Senior Lecturer, Department of Medicine, Imperial College London. Vishakha Sovani is Consultant Haematopathologist at the Haematological Malignancy Diagnostic Service Nottingham, Nottingham University Hospitals NHS Trust.