Paediatric Orbital Juvenile Xanthogranuloma: A Case Series and Review of the Literature.

PURPOSE: Juvenile xanthogranuloma (JXG) is a subtype of histiocytosis characterised histologically by foamy non-Langerhan cells with Touton giant cells. It typically manifests as a single self-limiting cutaneous nodule in the paediatric population. Orbital JXG is extremely rare, and its clinical course and management are not well understood or defined. Herein we present 3 cases of orbital JXG and provide a detailed literature review.

METHODS: Review of 3 cases with orbital JXG and literature review of all published cases.

RESULTS: Three presented cases demonstrate the heterogeneous clinical course of orbital JXG. Although centred around the use of steroids, there is neither robust evidence nor consensus on its management. The wider JXG literature is currently concentrated around the classification of JXG with respect to histiocytosis, especially the exclusion of extracutaneous JXG as separate diseases. This separation is based on clinical, histopathological, and molecular findings. It is unclear where orbital JXG best fits in this emerging classification of JXG.

CONCLUSION: Our review of the cases and literature on orbital JXG show that it may manifest with variable clinical course and its molecular pathogenic mechanism may be different to that of the cutaneous JXG.