Presentation
Incidental finding during KUB examination. No pain at the chest region.
Patient Data
There is a large mass seen arising from the 9th rib posteriorly at the right side of the dorsal spine with rings and arcs calcification or popcorn calcification, measuring about 8 x 7 cm, showing the following criteria:
- a narrow zone of transition
- sharply defined scalloped margins
- expansion of the overlying cortex
- no periosteal reaction
- no soft tissue mass
Case Discussion
Enchondromas (or chondromas ) are a relatively common benign medullary cartilaginous neoplasm with benign imaging features. Mostly, they are an incidental finding. They are usually asymptomatic. It is important to note that if an enchondroma is painful in the absence of a fracture, it should be considered malignant.
Distinguishing between enchondromas and low-grade conventional chondrosarcomas is a frequent difficulty as the lesions are both histologically and radiographically very similar. It is important to remember, though, that differentiating between them may be a moot point since both can either be closely followed up clinically and radiologically or treated if symptomatic. The large size and pain favor chondrosarcomas.
Another differential diagnosis could be added which is fibrous dysplasia due to the variability of the appearance of fibrous dysplasia.