Castleman disease (CD) describes a rare group of lymphoproliferative disorders with characteristic histopathological appearances.1 Unicentric CD (UCD) presents with isolated lymphadenopathy, usually accompanied by mild or localised symptoms. In contrast, multicentric CD (MCD), presents with lymphadenopathy across multiple sites, usually accompanied by mild to life-threatening constitutional symptoms. MCD represents a constellation of different clinicopathological subtypes that vary in their aetiology, presentation and management.

The incidence of all forms of CD is estimated at 21–25 per million person-years, based on insurance registries in the USA.2 Application of this rate to the UK adult population provides an estimated incidence of CD in the UK of 1100–1300 patients per year.3 There is an approximately even distribution of CD between men and women. UCD is most commonly diagnosed in the fourth decade of life, whereas MCD usually presents later in the fifth and sixth decades.45 The introduction of the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) code D47.Z2 in 2016 should facilitate the understanding of the epidemiology of the disease.6

Declaration of Interests

The BSH paid the expenses incurred during the writing of this guidance. None of the authors had conflicts of interest to declare. All authors have made a declaration of interests to the BSH and Task Force Chairs which may be viewed on request.