Eosinophilic granuloma of the thoracolumbar junction in the adult spine: A case report and review of literature

Abstract

Langerhans cell histiocytosis (LCH) is a common disease in the pediatric population with a peak incidence between 5 and 10 years of age. Eosinophilic granuloma (EG) accounts for less than 1% of all primary bone tumors primarily affecting the skull, pelvis, ribs and metaphyses of long bones and is a benign localized form of LCH. It is extremely rare in adults, more so in the spine, with a predilection for the thoracic spine than the lumbar and cervical region. A 35-year-old gentleman presented with transitional mid back pain for two months radiating to the right flank which worsened at night. There was no history of fever or trauma. Physical examination revealed right dorsolumbar tenderness without any neurological deficit. Serological parameters were normal and C-reactive protein (CRP) was negative. X-ray showed radiolucency in the right D12 pedicle with CT scan showing a lytic lesion in D12 body extending into the right pedicle. Magnetic resonance imaging (MRI) showed a hypointense lesion on T1 and hyperintense lesion on T2. Transpedicular biopsy was done and histopathology revealed Langerhans cell with abundant basophilic cytoplasm and a centrally placed nucleus with a groove. On further confirmation with IHC, a diagnosis of LCH was made. He then received radiotherapy for 12 days. PET CT done one year after diagnosis revealed near-total metabolic response of the tumor after comparing the PET CT done prior to diagnosis. The patient has reported complete relief since 2 years with recent radiological evidence of no recurrence. A precise diagnosis of LCH largely relies on biopsy and histopathology and once definitive diagnosis is established, EG can be managed by chemotherapy and/or radiotherapy in patients with no neurological deficit. Despite its rarity, EG should be considered as an important differential for solitary osteolytic lesions at the thoracolumbar junction in the adult spine.