Juvenile xanthogranuloma of peripheral nerve: a report of two cases.

As a rule, juvenile xanthogranuloma (JXG) is a cutaneous lesion most often occurring in infancy. An inflammatory process of unknown etiology, it is self-limited and benign in nature. The spectrum of JXG has expanded to include adult examples, multifocal lesions, and ones arising at extracutaneous locations. Although a variety of extracutaneous sites may be affected, few reported lesions have involved cranial or peripheral nerves. Solitary examples have been reported in trigeminal nerve and spinal nerve root; affected individuals were children or adolescents. An optic nerve lesion has also been described. We describe two additional cases of JXG of nerve. One patient developed multiple dorsal nerve root lesions, as well as skin involvement. The other case featured isolated involvement of the left radial nerve. Both patients were adults with no known underlying systemic disorder. These cases further expand the spectrum of extracutaneous JXG, and underscore its consideration in the differential of nerve "tumors."