Bursa formation with scapular osteochondroma in hereditary multiple exostosis.

Osteochondroma is the most common benign bone tumour present multiple hereditary exostosis (HME). Scapular osteochondroma associated with pain and bursitis is rarely reported in literature. Here, we describe a 49-year-old male with the diagnosis of HME who was admitted to the Department of Thoracic Surgery with a painful and rapidly enlarging mass behind the left scapula. Computed tomography and magnetic resonance imaging indicated a large bursa formation associated with chest wall mass. Pre-operatively, the mass was diagnosed as osteochondroma and resected. Pathological findings confirmed that mass was a large bursa formation due to scapular osteochondroma without any evidence of malignancy. Osteochondroma should be considered in differential diagnosis of chest wall tumours located at this specific site. We discuss this rare complication of HME and emphasize the importance of early diagnosis and differentiation from malignant transformation of osteochondroma.