This study reports two rare cases of thoracic outlet syndrome (TOS) caused by fibrous dysplasia of the first rib. Two patients, aged 19 and 29 years old, were admitted with TOS in the lower trunk of the brachial plexus caused by an inflated first rib. In these two cases symptoms included hypoesthesia of the anterior medial aspect of the forearm and two fingers in the ulnar side, and progressive weakness of the upper limbs. Surgery was required to resect the first rib. Transaxillary and supraclavicular excisions were challenging to perform due to the involvement of the subclavian vasculature and brachial plexus. Thoracoscopy was used in these cases in order to peel the pleura off the first rib and facilitate resection by the supraclavicular approach. None of the patients exhibited nerve or vascular complications following the surgery.
Keywords: fibrous dysplasia; first rib; resection; thoracic outlet syndrome; thoracoscopy.