Non-Hodgkin lymphoma

### What you need to know Non-Hodgkin lymphoma are malignant disorders arising from cells of the immune system, and manifest predominantly as lymphadenopathy or solid tumours. The classification of non-Hodgkin lymphoma is complex and ever-evolving, with more than 50 different subtypes listed in the latest World Health Organization classification.1 For non-specialists, however, they can most usefully be categorised as low grade (indolent) or high grade (aggressive) lymphoma since this broad distinction determines the likely natural course and management of the disease. In this clinical update we discuss the principles of diagnosis and management that are of particular relevance to non-specialist physicians, who may encounter patients with non-Hodgkin lymphoma during their initial presentation, therapy, and follow-up. ### Sources and selection criteria We searched PubMed using the key words “non-Hodgkin lymphoma,” “diffuse large B cell lymphoma,” and “follicular lymphoma” to identify reviews and major studies published since 2000. This was supplemented by a review of management guidelines (listed in the “Further educational resources” box), by personal experience of the authors, and by feedback from patients. Non-Hodgkin lymphoma is the sixth commonest malignancy in the UK with 13 000 new cases diagnosed annually (fig 1).34 The International …