[Operative case of eosinophilic granuloma of the skull with dural invasion].

Eosinophilic granuloma is the localized form of Langerhans' cell histiocytosis. There are several reports of magnetic resonance (MR) imaging of eosinophilic granuloma of the skull, however there are few reports about dural enhancement. We report an operative case of eosinophilic granuloma of the skull with dural invasion. A 42-year old man was admitted to our hospital. He was neurologically intact and there were no other osseous or soft tissue lesions. CT showed an osteolytic lesion in the left parietal bone. MR images showed the lesion as isointense on T1-weighted, and high intense on T2-weighted images. T1-weighted images with Gd-DTPA demonstrated the mass which was enhanced with dural surface and subgaleal tissue. The angiogram demonstrated a tumor stain fed by the left occipital artery. Bone scintigraphy demonstrated a solitary lesion showing peripheral uptake with a central defect. The patient underwent craniectomy with removal of the dura and a subgaleal lesion. Histological examination revealed characteristic eosinophilic granuloma with dural invasion. No recurrence of the lesion was demonstrated 6 months after surgery.