Langerhans cell histiocytosis is an uncommon condition and it is unusual for it to present in children under one year of age. Our aim is to review the clinical presentation, and present the radiologic findings and clinical outcome in this particular cohort of patients and determine how this differs from the imaging features of older children presenting with LCH. Materials and methods: A database of 17 patients with LCH who presented between 0 and 12 months of age was retrospectively reviewed. Radiologic findings, initial clinical presentation and ultimate clinical outcome were documented in table format. Results: Eight patients (47 %) initially presented with cutaneous stigmata, seven patients (41 %) had skeletal involvement, five patients (29 %) had splenic involvement, two patients (24 %) had central nervous system involvement either at presentation or at follow-up, three patients (18 %) had lymphadenopathy, two patients (12 %) had liver involvement, and two patients (12 %) had gastrointestinal (GI) involvement. Four patients (24 %) had multisystem involvement either at presentation or at follow-up. One patient died during follow-up. Conclusion:LCH in children under one year of age is uncommon and may have an unusual clinical presentation. The radiologic findings are varied and may differ from the classical imaging appearance more commonly seen in the older age group, with multisystem involvement seen more readily in younger patients.

anaemia, transient abnormal myelopoiesis, post-transplant lymphoproliferative disorder and Fanconi anaemia. Of the remaining 154 patients diagnosed with cancer, 88 (57.1%) were classified as 'green' according to the Royal Marsden Hospital 'Stop-light' system. 48 (31.2%) were classified as 'orange' and 18 (11.7%) were classified as red, qualifying for automatic referral to clinical genetics. Conclusions A significant proportion of patients diagnosed with cancer in OLCHC may benefit from referral to clinical genetics and screening for underlying cancer predisposition syndromes.