Hemothorax caused by costal exostosis injuring diaphragm: a case report and literature review

Abstract

Background Osteochondromas, also known as exostoses, are the most common benign tumors of bone and can be classified into isolated and multiple osteochondromas. A great majority of osteochondromas is asymptomatic, painless, slow-growing mass, and incidentally found. However, osteochondromas occurring in adolescence or in adult patients can grow in size and become symptomatic as a result of mechanical irritation of the surrounding soft tissues or peripheral nerves, spinal cord compression, or vascular injury. Case presentation We present a case of a 13-year-old girl with spontaneous hemothorax, the cause of which was identified by limited thoracotomy with the aid of video-assisted thoracic surgery to be bleeding from a diaphragmatic laceration incurred by a costal exostosis on the left sixth rib. Preoperative chest computed tomography (CT) depicted a bony projection arising from the rib and bloody effusion in the intrathoracic cavity, but was unable to discern the bleeding cause from the lung or the diaphragm. This case will highlight our awareness that costal exostosis possibly results in bloody pleural effusion. Meanwhile, English literatures about solitary costal exostosis associated with hemothorax were searched in PubMed and nineteen case reports were obtained. Combined our present case with available literature, a comprehensive understanding of this rare disease entity will further be strengthened. Conclusions Injury to the diaphragm is the primary cause of hemothorax caused by costal osteochondroma, including the present case. Thoracic CT scan can help establish a diagnosis of preoperative diagnosis of costal osteochondroma. Surgical intervention should be considered for those patients with symptomatic osteochondroma of the rib. Combined with our case and literature, prophylactic surgical removal of intrathoracic exostosis should be advocated even in asymptomatic patients with the presentation of an inward bony spiculation.

Osteochondroma of the Rib: A Potentially Life-Threatening Benign Tumor

“…Osteochondromas are projections or exostoses on the external surface of the bone, with the presence of cortical and medullary continuity with the parent bone and a hyaline cartilage cap [2,3]. Typically, they originate in the metaphyseal region of long bones (distal femur, proximal tibia, and humerus), growing away from the adjacent joint [2,4].…”

“…Most cases manifest as solitary lesions (85%), with approximately 15% exhibiting multiple tumors in the context of multiple hereditary exostoses (HME), an uncommon genetic disorder with an autosomal dominant inheritance pattern [ 2 ]. Osteochondromas are projections or exostoses on the external surface of the bone, with the presence of cortical and medullary continuity with the parent bone and a hyaline cartilage cap [ 2 , 3 ]. Typically, they originate in the metaphyseal region of long bones (distal femur, proximal tibia, and humerus), growing away from the adjacent joint [ 2 , 4 ].…”

“…Additionally, a cartilaginous matrix within the cartilage cap is often visible as rings and arcs of calcifications [ 2 ]. Cross-sectional imaging such as tomography (CT) and magnetic resonance imaging (MRI) are used to evaluate the cartilage cap, and marrow continuity with the parent bone in complex anatomical regions and assess complications [ 2 , 3 ]. CT scans, with 3D reconstructions, clearly described the morphology, extent, and growth pattern [ 3 ].…”

“…Cross-sectional imaging such as tomography (CT) and magnetic resonance imaging (MRI) are used to evaluate the cartilage cap, and marrow continuity with the parent bone in complex anatomical regions and assess complications [ 2 , 3 ]. CT scans, with 3D reconstructions, clearly described the morphology, extent, and growth pattern [ 3 ]. MRI, on the other hand, excels in depicting tumor morphology, and cartilage thickness, detecting bone or adjacent soft tissue edema (bursitis), and identifying neurovascular complications [ 2 ].…”

“…Osteochondroma is one of the most common benign bone tumors, characterized by the appearance of a bony prominence on the outer surface of the bone [1]. Although it is usually asymptomatic in most cases, clinical symptoms may vary depending on its location and size [1][2][3]. Despite the relative frequency of osteochondromas, their occurrence in the ribs and their association with serious complications such as hemothorax are extremely rare, even in the pediatric population [1].…”