Unusual presentation of osteochondroma (Trevor's disease)

Osteochondromas are common benign tumors. They probably are developmental malformation rather than true neoplasm and are thought to originate within the periosteum and small cartilage nodule. They rarely develop in the joint. Trevor disease or dysplasia epiphysealis hemimelica (DEH) refers to intraarticular epiphyseal osteochondroma. DEH has an incidence of 1 in 1 million and is characterized by asymmetric overgrowth of cartilage. Though many cases of DEH are asymptomatic, but they may be troublesome when they cause mechanical and pressure symptoms depending on the size and location. We report a case of Trevor's disease of the knee in a 21-year-old male with mechanical obstruction.