Spiculated periosteal reaction

Last revised by Soham J Patel on 1 May 2024

Spiculated periosteal reaction represents spicules of new bone-forming along vascular channels and the fibrous bands that anchor periosteum to bone (Sharpey fibers).


A spiculated periosteal reaction signifies a rapid underlying process that prevents the formation of new bone under the raised periosteum.


The orientation of the spicules reflects the direction of tumor growth. Spiculated periosteal reactions can be divided into subtypes based on the orientation of the spicules:

Perpendicular (hair-on-end)
Divergent (sunburst)
Focal slopping (velvet)

See also

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