It is used for describing the margins of a lytic bone lesion. It is used to possibly differentiate benign from malignant bone lesions on preliminary imaging of lesion evaluation.

Classification

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 system should only be used to narrow down the list of differential diagnosis on preliminary imaging. Type 2 and 3 lesions are generally aggressive lesions and can be used as indication for further evaluation for malignancy.
Type 1A is usually indicative of a benign lesion with slow growth potential; For e.g. Simple bone cyst).
Type 1B appearance can have an overlap from malignant lesions.
Diagnosing the lesion based on types IC, II and III may be difficult on preliminary imaging and further imaging (CT or MRI) is always needed with histopathology correlation.

Contributed by – Dr. Varun Tyagi, Mumbai