Follow-up analysis of lesion characteristics of enchondromas and atypical cartilaginous tumours of the knee and shoulder region on MRI

Question Both singular MRI and histological examination have limitations regarding differentiation of enchondromas (EC) and atypical cartilaginous tumours (ACTs). Findings Median ACT growth rates were 0.039 mm/month (knee) and 0.083 mm/month (shoulder), while median growth rates of EC in the knee and shoulder were 0.0 mm/month. Clinical relevance Active surveillance is a safe strategy when dealing with ECs and ACTs of the long bones; follow-up MRIs may support tumour distinction of cartilage lesions, as ECs and ACTs show different growth behaviour.