However, it cannot be used to predict if the growth of tumor is inward in regards to the cap.[4] Angiography is used to detect vascular lesions caused by osteochondroma due to ossified cartilaginous cap. It is also used to characterize malignant transformation lesions through neovascularity.[4] Clinical testing such as sequence analysis can be done of the entire coding regions of both EXT1 and EXT2 to detect mutations.[12] A biopsy of the tissue sample of the tumor can also be taken to check for cancer.[11]