Multiple hereditary exostoses (MHE) is an autosomal-dominant disorder characterized by the formation of ectopic, cartilage-capped, growth plate–like exostoses. The goal of this video is to discuss the exceptional case presentation of a young patient with MHE of the ribs. The patient is a 16-year-old individual with a family history of MHE who had left-sided atraumatic chest pain. Radiographs and CT scans of the patient's chest revealed exostoses at the left third, fourth, and sixth ribs and intact bone cortex.

Under general anesthesia, a double-lumen endotracheal tube was inserted for unilateral ventilation. A skin incision was made in the most superior aspect of the axilla, posterior to the pectoralis major muscle and anterior to the latissimus dorsi muscle. The fifth intercostal space immediately beneath the skin incision was located, and the intercostal muscles were separated from the superior aspect of the rib to avoid nerve injury. Three substantial exostoses were identified in the left side of the chest via thoracoscopy. The exostoses scratched the pericardium during cardiac pulsations under unilateral ventilation. Each exostosis was resected with the use of a chisel via an additional 4-cm long mini-thoracotomy incision to prevent organ injury and recurrent exostoses. The lung was re-expanded to evaluate correct ventilation.

Pathologic examination showed costal exostoses measuring 2 cm × 1 cm in the third rib, 2 cm × 0.5 cm in the fourth rib, and 2.5 cm × 1.5 cm in the sixth rib. MHE rarely involve the ribs, spine, metatarsals, metacarpals, and phalanges; however, the risk of malignant transformation is increased at axial sites. Osteochondroma grows in size and gradually ossifies during skeletal development and stops growing at skeletal maturity, after which no new osteochondroma develops. Patients with MHE with an absence of clinical problems do not require therapy; however, therapy is recommended in patients in whom a risk for lethal thoracic organ injury or risk of hemothorax from trauma or a vascular wound directly caused by the tip of the exostosis is suspected. Video-assisted thoracoscopic surgery is a minimally invasive surgical technique used to successfully manage symptomatic costal exostoses and decrease thoracotomy morbidity.