“…Occasionally, large XGs of the choroid plexus requir ing surgical intervention for symptoms related to a mass effect or obstructive hydrocephalus in both children [16][17][18][19] and adults [20][21][22][23][24][25][26][27][28][29][30][31][32][33] have been reported. These 'chor oid plexus XGs' are considered pseudoneoplastic [9,14], and can be distinguished from JXG by their histologic appearance, which consists chiefly of foamy histiocytes, cholesterol crystals, and eventually, giant cells and inflam matory infiltrates [9], Intracranial dural [34][35][36], spinal dural [37], and dif fuse leptomeningeal involvement [38] with XGs have been reported. Dural based forms generally occur in indi viduals with Langerhans cell histiocytosis, including Hand-Schuller-Christian (HSC) or Weber-Christian dis ease, and are generally distinguishable from JXG by his tological, immunohistochemical and electron microscop ic features [9,10,34,35,39], However, three recent reports of dural-based lesions more characteristic of JXG in children without HSC or Weber-Christian disease are unusual and noteworthy.…”