Lodwick classification of lytic bone lesions

Last revised by Andrew Murphy on 1 Feb 2021

The Lodwick classification is a system for describing the margins of a lytic bone lesion (or lucent 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.

In 2016 the "modified Lodwick-Madewell grading system" was proposed in an attempt to better reflect the risk of malignancy in each category 4.

Practical points

Differentiation between types II and III 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.

See also

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Cases and figures

  • Figure 1: revised Lodwick classification
    Drag here to reorder.
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