Table 1 Diagnostic criteria of ECD

Radiology

Radiography

Bilateral symmetric diametaphyseal osteosclerosis of long bones

^99mTc Bone Scintigraphy

Symmetric and abnormally strong 99mTc labeling of the distal ends of the long bones

Histology

Microscopic Environment

Non Langerhans histiocytes with foamy or eosinophillic cytoplasm, polymorphic granulomae and fibrosis, xanthogranulomatosis, proliferating fibroblasts, lymphocytic aggregates, Touton giant cells

Histiocyte Immunostaining

CD68(+), CD1a(−), S-100(negative/low) ^*

Histiocyte Ultrastructure

Lack of Birbeck granules