Skeletal manifestations of eosinophilic granuloma (eg)

short notes about Skeletal manifestations of eosinophilic granuloma (EG) summarized by Dr laith fadhel / radiologist

1. Skeletal manifestations of eosinophilic granuloma (EG ) Presented by Dr.laith Fadhel reference David Sutton 1340

2. Epidemiology / The skeletal system is the commonest site of involvement of  Langerhans cell histiocytosis , and in for 60-80% of cases is the only organ system involved. Aged affected / children 3-12 years / young adult / male predominance location / skull , pelvis , femora , diaphysial predilection S ymptoms / pain , swelling , fever Presentation / solitary , multiple lesions Radiological sign / lucent area of bone distraction , Sharpe oval or scalloped margin , bone expansion , in chronic phase with sclerotic margin , collapse vertebra DDX / osteomyelitis , Ewing's tumor , in spine / metastases , atypical TB , neuroblastoma

3. Skull Isolated lesion Bone expansion Sharpe margin Oval , scalloped DDX / epidemoid or fibrous dysplasia

4. Spine collapse vertebra { vertebra plana } wall bulging laterally disc intact Para spinal soft shadow

5. Spine collapse vertebra { vertebra plana } wall bulging laterally disc intact Para spinal soft shadow CT / cortical erosion and soft tissue involvement

6. Spine MRI / T1  - typically low signal  T2  - isointense to hyper intense  STIR  - hyper intense T1 C+ (Gd)  -  often shows contrast enhancement

7. PT Bone scan Variable appearance on bone scintigraphy with lesions showing an increased or decreased tracer uptake depending on the histological picture. Nonetheless bone scans are helpful in other asymptomatic lesions.