Juvenile xanthogranuloma: challenges in complicated cases.

Juvenile xanthogranuloma (JXG) is one of the most common forms of non-Langerhans cell histiocytosis in children. Although it usually presents as a self-limited skin lesion with typical histopathology, JXG can be challenging to diagnose due to an atypical initial presentation with corresponding variable histopathology for different stages of development. We present challenging cases of JXG from Sydney Children's Hospital, collected over 10 years - two with multisystem involvement and concomitant urticaria, one associated with neurofibromatosis, and one case of giant JXG with an initial histopathological challenge. Although JXG has been reported with urticaria pigmentosa, in two of our cases persistent urticaria, in association with JXG is discussed.