A 34 year old male presented with a painful, rapidly enlarging chest wall mass. A malignant chest wall neoplasm was suspected. X ray and thorax CT scan showed sixth and seventh internal ribs exostosis. Exostosis were resected the sixth and seventh ribs with thoracotomy. The pathological findings of those bony lesion proved to be consistent with osteochondroma.

Keywords:

Hereditary multiple exostoses, costal exostoses, osteochondroma