Radiculopathy as a manifestation of Langerhans' cell histiocytosis.

Langerhans' cell histiocytosis (LCH) is a rare condition of children and young adults in which Langerhans' cells proliferate. The clinical spectrum ranges from solitary or few focal lesions to multisystem involvement mimicking vasculitis or hematological malignancy. Focal bone lesions, known as eosinophilic granulomas, are the most common manifestations. Eosinophilic granuloma usually presents with a variable combination of pain, swelling, fracture, and fever. Facial bone involvement may manifest as an ear discharge, hearing loss, or exophthalmos. Nerve root pain is rarely reported, even in patients with lesions in the axial skeleton. We report four cases of nerve root pain caused by LCH. Two male patients aged 25 and 34 years, respectively, presented with truncated femoral neuralgia related to acetabular granulomas. A 25-year-old woman with involvement of the L5 vertebral body and a 41-year-old man with a sacral lesion presented with sciatica.