Unusual presentation of mastoid eosinophilic granuloma in a young patient

Eosinophilic granuloma is a well-recognized form of langerhans cell histioc ytosis, most commonly involving the skull bones, usually with an excellent prognosis. Recurrent and difficult to recognize osteolytic lesions of the s kull are encountered only rarely. A patient with recurrent eosinophilic gra nuloma of the skull is reported. In spite of appropriate multimodality trea tment, there were several recurrences, most recently with involvement of th e mastoid process. Imaging studies revealed extensive involvement of surrou nding structures with expansion of the tumor into the middle cranial fossa and slight pressure on the antero-medial portion of the temporal lobe of th e brain. Despite extensive involvement, the patient had no complaints. Beca use of the rarity of such silent and unpredictable lesions, a systematic ap proach with regular CT and MRI follow-up is suggested.