Costal Exostosis: A Rare Cause of Hemothorax.

SESSION TYPE: Pleural Cases IPRESENTED ON: Tuesday, October 23, 2012 at 11:15 AM - 12:30 PMINTRODUCTION: The most common cause of hemothorax is trauma. Non-traumatic hemothorax is uncommon and can be caused by malignancy, tuberculosis, blood dyscrasias, pulmonary embolism, thoracic aortic aneurysm, pulmonary artery aneurysm, arteriovenous fistula, connective tissue disease, and catamenial hemothorax. We present the case of a patient who developed a hemothorax as a result of a costal exostosis: a rare cause of spontaneous hemothorax.CASE PRESENTATION: A 22-year old male with no previous medical history presented with a 3-day history of severe pleuritic right-sided chest pain radiating to lower back associated with shortness of breath. He reported no infectious symptoms, cough, hemoptysis, or trauma to his chest. His vital signs were normal and he had decreased breath sounds on the right. A chest X-ray showed blunting of the right costophrenic sulcus and a bony abnormality of the right humerus. Pleural fluid analysis was consistent with a hemothorax. A computed tomography revealed a moderate sized right-sided effusion and multiple sub metaphyseal exostoses in both proximal humeri, as well as in the heads of multiple ribs bilaterally. Patient underwent video assisted thoracic surgery with pleurodesis and pleural biopsy. There was visual evidence that the costal exostosis was causing significant local inflammation of the pleura and causing hemorrhage. Pleural biopsy demonstrated inflammation, but no malignancy or infection. The patient was evaluated as an outpatient after his procedure with complete resolution of the pleural effusion and symptoms.DISCUSSION: Osteochondroma, also known as exostosis, is a benign tumor that contains both bone and cartilage and usually occurs near the end of long bones. It takes the form of a cartilage-capped bony spur or outgrowth on the surface of the bone. Spontaneous hemothorax can be a complication of costal exostoses, but the underlying etiology is still unclear. Shearing of the pleura or diaphragm by the margins of costal exostoses has been proposed. Examination of lung tissue adjacent to an exostosis has revealed fibrosis of the pleura and subpleural lung parenchyma, dilated muscular arteries, and bronchiolectatic cysts. It is important to consider costal exostosis as a cause of hemothorax.CONCLUSIONS: Vascular complications of costal exostosis including hemothorax and hemopericardium are rare, but potentially life-threatening. Treatment includes tube thoracotomy, throracoscopy and resection of the affected ribs. It is important to consider bony exostosis as a cause of spontaneous hemothorax, as this represents a treatable cause of a serious condition.1) Nakano Y, Endo S, et al. Hemothorax Caused by a Solitary Costal Exostosis. Ann Thorac Surg. 2009; 88:306.DISCLOSURE: The following authors have nothing to disclose: Karla Diaz, Diego Maselli, Manuel Rivera, Stephanie LevineNo Product/Research Disclosure InformationUniversity of Texas Health Science Center at San Antonio, San Antonio, TX.