Benign cartilage tumors

Benign cartilage lesions can be divided into those that differentiate towards fetal type cartilage (chondroblastoma and chondromyxoid fibroma) and those that differentiate towards mature hyaline type cartilage (osteochondroma, chondroma). Nora lesion is a reactive periostitis that mimics osteochondroma and is discussed with this group of lesions. This article reviews their clinical, radiological and pathological features along with the main differential diagnoses. It also briefly reviews multiple osteochondromas, multiple enchondromas and Maffucci syndrome.