Osteochondroma is the most common benign bone tumor and present as multiple masses in the hereditary disorder of multiple hereditary exostosis. It is usually painless without specific symptoms. However, it rarely causes symptoms such as mass effects that produce several mechanical problems, and malignant transformation of the cartilaginous cap. The deformities and interference with major joint function are the most frequent musculoskeletal complaints dependent on the location of the mass. Large bursa formation with mechanical symptom has been very rarely reported in osteochondroma in which bursa is over the cap. Here, we first described a patient with multiple hereditary exostosis who had developed huge bursitis on chest wall around the osteochondroma arising from the anterior surface of the right scapula after dumbbell lifting exercise for 3 months, and suggest that cystic mass can develop in any site of osteochondroma and should be early differentiated from malignant transformation of osteochondroma.