Radiological and clinicopathological features of orbital xanthogranuloma

Background-Orbital xanthogranuloma, a diagnosis confirmed histologically, o ccurs rarely in adults and children. With its characteristic macroscopic ap pearance the adult form may be associated with at spectrum of biochemical a nd haematological abnormalities including lymphoproliferative malignancies. Method-The clinicopathological features and imaging appearances on computed tomography and magnetic resonance imaging of this condition are described in eight adults and a child. Results-Radiological evidence of proptosis was present in seven patients. I n all nine patients an abnormal infiltrative soft tissue mass was seen, wit h increased fat in six cases. All patients had associated enlargement of ex traocular muscles suggestive of infiltration and five had lacrimal gland in volvement. Encasement of the optic nerve, bone destruction, and intracrania l extension was present only in the child with juvenile xanthogranuloma. Ha ematological and/or biochemical abnormalities were detected in seven patien ts and seven patients had other systemic diseases which were considered to have an immune basis. One patient subsequently developed non-Hodgkin's lymp homa. Conclusion-The investigation and management of orbital xanthogranulomas req uires a multidisciplinary approach even though the diagnosis may be suspect ed clinically. Imaging delineates the extent of disease and involvement of local structures and may influence the differential diagnosis. The juvenile form may be more locally aggressive, causing bone destruction with consequ ent intracranial extension.