- Rare form of histiocytosis
- Mean age 55 – 60 years
- M:F = 3:1
- Skeletal involvement 95%
- Cardiovascular involvement 50%
- Retroperitoneal fibrosis 30%
- CNS involvement
- Diabetes insipidus
- Exophthalmos
Imaging
- Bilateral, symmetrical cortical/medullary sclerosis of major long bone metadiaphyses with epiphyseal sparing
- Bone scintigraphy, PET-CT show increased uptake