Magnetic resonance imaging of calvarial eosinophilic granuloma with pericranial soft tissue reaction--case report.

A 4-year-old girl presented with an eosinophilic granuloma in the cranial vault. Magnetic resonance (MR) imaging showed the mass as slightly low intensity on T1- and high intensity on T2-weighted images. The pericranial soft tissue was densely enhanced after gadolinium-diethylenetriaminepenta-acetic acid infusion. The mass was soft and successfully removed. Histological examination disclosed Langerhans' cell histiocytosis. MR imaging is useful for the diagnosis of calvarial eosinophilic granuloma with soft tissue involvement.