November 20, 2012

Spinal Langerhans Cell Histiocytosis (LCH)

Figure 1: Tc-99m MDP bone scan (posterior image) shows a focus of increased activity at L2 vertebral body in a 24-year-old woman presenting with back pain.

Figures 2&3: Axial GRE T2W and sagittal post-contrast T1W MR images show a round focus of bone destruction surrounded by bone marrow edema and enhancement of L2 body, sparing the posterior elements. 

Facts: LCH
  • Rare, benign disorder of unknown etiology comprises of eosinophilic granuloma (unifocal), Hand-Schuller-Christian disease (multifocal) and Letterer-Siwe disease (disseminated variant) - these are different manifestations of a same disease
  • Clonal proliferation of Langerhans cells
  • Peak incidence 5-10 years but there is a shift toward younger children
Spinal LCH
  • Vertebral involvement in 8-25% of cases
  • Thoracic > cervical, lumbar
  • Vertebral body >> posterior elements
  • Solitary, well-defined osteolytic lesion with scalloped borders eventually progresses to collapse and a classic "vertebra plana"
  • Typically single vertebral body involved. Disc spaces spared
  • Soft tissue mass suggests more aggressive course
Main Imaging Differentials of Spinal LCH
  • Osteomyelitis
  • Ewing sarcoma
  • Leukemia, lymphoma, metastatic neuroblastoma

Reference:
Hosalkar HS, Greenberg JS, Wells L, Dormans JP. Isolated Langerhans Cell Histiocytosis of the T12 vertebra in an adolescent. Am J Orthop 2007;36: E21-E24.

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