TY - JOUR T1 - Osteochondroma of acromioclavicular joint JF - BMJ Case Reports JO - BMJ Case Reports DO - 10.1136/bcr-2019-230246 VL - 12 IS - 8 SP - e230246 AU - Muhammad Nouman Baig AU - Sandra O’Malley AU - Christopher Fenelon AU - Ken Kaar Y1 - 2019/08/01 UR - http://casereports.bmj.com/content/12/8/e230246.abstract N2 - Osteochondroma is the most common type of benign bone tumour. It is a benign chondrogenic lesion derived from aberrant cartilage from the perichondral ring, and it commonly presents in the proximal humerus, proximal femur and knee. Osteochondroma is usually solitary but can be multiple with patients with hereditary multiple exostoses. Malignant changes happen in approximately 1% of cases. Osteochondroma usually causes local pain or swelling. We discuss a unique case of an osteochondroma that highlights the fact that osteochondroma can occur in the most unlikely places, and they should be properly visualised via radiography to evaluate any extensions and compromised surrounding structures before surgical intervention. ER -