Langerhans histiocytosis of temporal bone: role of magnetic resonance imaging.

Abstract

Langerhans cell histiocytosis (LCH) may involve nearly every organ of the body. In children, head and neck involvement has been reported in as many as 82% of patients. Sites of head and neck involvement include skull, temporal bone, orbit, mandible, maxilla and cervical nodes. In addition, patients may have coexisting central nervous system (CNS) involvement adjacent to, or remote from, osseous lesions. Magnetic resonance imaging (MRI) of the temporal bone in patients with LCH is ideal for evaluating the extracranial extent of the soft-tissue mass and is complementary to computed tomography (CT) in the assessment of osseous erosion. MRI is superb in the evaluation of intracranial extension, usually into the middle cranial fossa, and of patency of adjacent vascular structures. It is the imaging modality of choice to evaluate patients with suspected CNS involvement of LCH, which includes lesions of the infundibulum, cerebrum, cerebellum, and extra-axial spaces.