The Lodwick classification is a system for describing the margins of a lucent/lytic bone lesion. The terms used in the description suggest the level of concern for an aggressive, and possibly malignant, process.
type 1: geographic
- 1A: thin, sclerotic margin
- 1B: distinct, well-marginated border, but not sclerotic
- 1C: indistinct border
- type 2: moth-eaten
- type 3: permeative
The classification scheme is vaguely ordinal, with higher numbers representing more aggressive disease, but the terminology should be used more as a way to suggest a range of differential diagnoses than as an indication of malignancy (for instance, benign osteomyelitis could have a type 3 appearance).
Type 1A is usually indicative of a benign lesion with slow growth kinetics (e.g. unicameral bone cyst). Treated metastases may also show a sclerotic rim, however.
The differential for type 1B lesions contains malignant lesions.
Differentiation between types 2 and 3 may be difficult, but often the distinction is not essential, and further imaging (CT or MRI) should be pursued.
Mixed types are possible in some scenarios (for instance transformation of a benign lesion into a malignant lesion).
In addition to the Lodwick classification, periosteal reaction may help characterize a bone lesion.
- 1. Lodwick GS, Wilson AJ, Farrell C et-al. Determining growth rates of focal lesions of bone from radiographs. Radiology. 1980;134 (3): 577-83. doi:10.1148/radiology.134.3.6928321 - Pubmed citation
- 2. Lodwick GS, Wilson AJ, Farrell C et-al. Estimating rate of growth in bone lesions: observer performance and error. Radiology. 1980;134 (3): 585-90. doi:10.1148/radiology.134.3.6986621 - Pubmed citation
- 3. Morrison WB, Sanders TG. Problem solving in musculoskeletal imaging. Mosby. ISBN:0323040349. Read it at Google Books - Find it at Amazon