Purpose: To describe, illustrate and understand the relationship between the various periosteal reaction patterns of bone lesions and the underlying pathologies, whether intra or extra-osseous.
Material & Methods: We reviewed the combined teaching files available to one of us (NH), comprising a collection of over 50.000 pathology-proven musculoskeletal cases. We extracted characteristic periosteal reaction patterns that are illustrative and sometimes classically associated with specific pathologies, and when not, associated those patterns with the underlying pathology and class of pathology present.
Results: Periosteal reaction patterns of unilamellar, multi-lamellar, spiculated and blow-out are augmented with other features such as uninterrupted or interrupted coverage (cortical bubbling sign) or thick, unilamellar periosteal reaction patterns. Benign versus malignant features were classically recognized decades ago. Newly identified disorders fit models of classic patterns. Some periosteal reaction patterns can be discerned using MR and some patterns become misleading using MR.
Conclusion: Periosteal reaction patterns can serve as differentiators between high ranked items on a differential list. Understanding periosteal reaction patterns can shorten or even eliminate further workup requirements.
Classical musculoskeletal radiology is still essential knowledge, despite fancy imaging techniques.
The more things change, the more they remain the same.
