A permeative, moth-eaten lesion of a diaphysis or flat bone with lamellated (onion-skin) or spiculated periosteal reaction and a soft tissue mass larger than the bone destruction suggests — in a child or young adult.
Orient first
- Second commonest primary bone sarcoma of youth after osteosarcoma; pelvis and long-bone diaphyses.
- Osteomyelitis and LCH mimic it clinically and on imaging.
- Staging: whole-bone MRI for skip lesions, chest CT and PET-CT or whole-body MRI for metastases.
Acquire the study
- Radiographs in two planes; MRI of the whole bone with the adjacent joints before biopsy.
The manoeuvre
- On two orthogonal radiographs: permeative or moth-eaten destruction with a wide zone of transition.
- Periosteal reaction along the cortex: lamellated, spiculated, Codman triangle.
- Location on the AP projection: diaphyseal vs metaphyseal, or a flat bone (pelvis, rib, scapula).
What confirms it
- Histology with molecular confirmation (EWSR1 rearrangement) after biopsy planned with the treating sarcoma centre.
What licenses you to exclude it
- A normal radiograph does not exclude early marrow disease; MRI does.
The classic misread
- Biopsying outside a sarcoma centre through a route that contaminates the resection.
- Calling it osteomyelitis and delaying tissue.