A case report of unifocal Langerhans' cell histiocytosis or eosinophilic granuloma.

A case of unifocal Langerhans' cell histiocytosis or eosinophilic granuloma in a child is reported where the frontal, zygomatic and maxillary bones of the left orbital wall are affected. As eosinophilic granuloma is a rare disease and the involvement of maxillary bone in orbital eosinophilic granuloma is not well documented in the literature, this case is reported for its unusual involvement of 3 bones at a single site. The diagnosis was established by clinical, radiological and histological findings. As no other system or site was involved and considering the osseous involvement of multiple bones at one site, local radiotherapy was preferred as the mode of treatment. The patient responded favourably to radiotherapy with reduction of proptosis and tumour mass but there was no visual recovery. In the absence of universal agreement over the mode of treatment, the result emphasises the probable benign nature of the tumour and the need to withhold more aggressive treatment modalities for extensive multisystem involvements.