The first mode of investigation for a lump (especially in a pediatric patient) should be an ultrasound. In this case, the diagnosis was made on the ultrasound, but an X-ray allows a clearer picture of the extent of the osteochondroma.

Measuring the cartilage cap on the osteochondroma is important, especially where the patient describes pain because of the relationship between the thickness of the cartilage cap and malignant transformation. In children, it is exceptionally rare.