LAUSR

A previously healthy 9yearold boy presented to dermatology outpatient clinic with a 2month history of an enlarging nodule on the anterior right shoulder (figure 1). There were no specific symptoms, family history or relevant medical history. Examination demonstrated a 1×1 cm indurated yellow nodule with ulceration. Differential diagnoses included giant molluscum, giant juvenile xanthogranuloma (JXG) and keratoacanthoma. Histology from an incisional biopsy demonstrated surface excoriation and focal erosion with underlying dense monomorphous histiocytic population with abundant eosinophilic infiltration (figure 2), confirming the diagnosis of JXG. Treatment options included observation for selfinvolution and surgical excision of the lesion. Generally, surgical management is reserved for symptomatic lesions as this may result in scarring, local infection and, in some cases, recurrence. Three months later, signs of spontaneous regression were observed. This is not uncommon, as the treatment for solitary JXG is usually observation, with lesions typically regressing in 3–6 years. What is unique about this case, however, is the unusual site and age of presentation. JXG is a benign histocytic infiltrative disease of unknown aetiology. It typically presents before the age of one, with lesions often described as yellow papules with a ‘setting sun’ appearance. Typically, there is a solitary asymptomatic lesion on the neck or head measuring between 1 and 10 mm in diameter. A few reports have described JXG on the trunk. Both paediatricians and paediatric dermatologists need to be aware of giant JXG as a differential for rapidly progressing skin lesions. Molly Papadopoullos, Lucy Smith , Muhammad Aslam, Periasamy Balasubramaniam School of Medicine, Cardiff University, Cardiff, UK Department of Dermatology, Betsi Cadwaladr University Health Board, North Wales, UK Department of Histopathology, Betsi Cadwaladr University Health Board, North Wales, UK