Dermatological manifestations of inherited cancer syndromes in children

Various cutaneous signs presenting in childhood, for example café-au-lait macules, may have systemic cancer associations. Indeed, this may be the first manifestation of the underlying cancer predisposition. The syndromes covered in this review fall into four main categories: (i) DNA damage processing defects including Fanconi anaemia, ataxia telangiectasia, Bloom syndrome, Rothmund-Thomson syndrome, constitutional mismatch repair defects and xeroderma pigmentosum; (ii) signalling pathway defects, including naevoid basal cell carcinoma and Costello syndromes; (iii) primary immunodeficiency syndromes; and (iv) syndromes that do not fit this molecular classification, such as X-linked dyskeratosis congenita. This review focuses on the dermatological findings of these conditions. Some of these conditions exhibit a milder heterozygous phenotype and this should be elicited in the family history. Where the dermatological findings are subtle, a targeted family history can provide clues towards making a diagnosis. Nondermatological features of each condition are summarized too, together with molecular testing strategies, which will direct genetic counselling and screening. This review will enable the dermatologist and other clinicians in the early recognition and molecular confirmation of underlying cancer-predisposing syndromes. This allows the possibility of surveillance and prevention strategies to be initiated in a timely manner, in affected children and other at-risk family members.