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Orthopedic Surgery

Training Level

Resident PGY 2


Henry Ford Hospital


PURPOSE: Osteochondromas (OCE) are typically characterized as benign cartilaginous neoplasms occurring as either solitary lesions or as part of multiple hereditary exostosis (MHE). In some instances, they may cause pain due to irritation of nearby musculoskeletal structures such as ligaments, tendons, nerves and vessels. Growth of these lesions is often slow and mimics skeletal growth. Rapid change in the size of an OCE warrants investigation due to concern for malignant transformation. Presented here is the case of a 17 year old male who noted rapid ongoing growth in a humeral osteochondroma secondary to development of a brachial artery pseudoaneurysm. METHODS: 17 year old male avid basketball player presents with history of MHE who is status post resection of OCE lesions about his knee. He reported a one year history of significant and progressive growth of a lesion in his right medial upper arm associated with mechanical pain (especially during basketball), night pain and occasional numbness. Physical exam revealed a large, firm and relatively immobile non-pulsatile mass just distal to the axilla without adjacent adenopathy. CT scan revealed a 10 cm mass with subjacent cortical irregularity concerning for a mass/sarcoma with hemorrhage versus pseudoaneurysm. MRI was most suggestive of a pseudoaneurysm with displacement of the neurovascular structures. MRA and CT angiogram confirmed the suspected pseudoaneurysm. He subsequently underwent successful resection and repair of the pseudoaneurysm in addition to resection of the offending exostosis by Orthopaedic oncology. His recovery to date has been unremarkable. DISCUSSION: Vascular complications associated with OCE are rare, with around 100 reported in the literature. The most common location for vascular findings is typically the popliteal artery, likely secondary to the knee being a common location for OCE’s, frequent trauma to the area and the relative tethering of this artery about the knee. The humerus is decidedly an uncommon location despite the shoulder’s large range of motion. Conclusion: Rapid or ongoing enlarging OCE’s require prompt medical attention and work up. Whereas sarcomatous degeneration needs to always be considered, other etiologies such as pseudoaneurysms need to be included in the differential diagnosis. Presented is a case report of the rare complication of an OCE leading to a brachial artery pseudo-aneurysm in the upper extremity. Recognition of this potential diagnosis aided in appropriate imaging without disastrous open or needle biopsy and an ultimate successful outcome.

Presentation Date


Brachial Artery Pseudoaneurysm Secondary to a Sessile Osteochondroma in an Avid Teenage Basketball Player