Eosinophilic Granuloma as a Solitary Lytic Lesion of the Cervical Spine in a Child

INTRODUCTION: Eosinophilic granuloma (EG) is a type of Langerhan cell histiocytosis (LCH) with unknown etiology. This benign tumorous lytic lesion affects mainly children or young adults, causing bone destruction. Although, the flat or the long bones are commonly affected, localized spinal involvement in pediatric age group is rare. A thorough workup is therefore necessary for this condition, which may mimic other severe conditions. CASE REPORT: A 10-year-old girl presented with neck pain for 4 months without any history of trauma, fever, or neurological weakness. An X-ray revealed radiolucency and sclerosis of the fifth cervical vertebral body, which was hypointense on T1 and heterogeneous on T2-weighted image, with mild peripheral enhancement on fat-suppressed post-contrast T1-weighted image. Biopsy histomorphology revealed a lymphohistiocytic lesion with scatted histiocytes with grooved nuclei, immunopositive for Langerin; thus consistent with LCH (EG). She was managed conservatively with a completely pain free course with full range of movement at 1-year follow-up. Her follow-up X-ray showed complete remodeling and ongoing fusion. CONCLUSION: EG should be considered as a differential diagnosis in the evaluation of solitary lytic lesion involving spine in pediatric age group. This, although self-resolving, may occasionally need surgical intervention with or without adjuvant therapy.