Angiosarcoma around total hip arthroplasty: case series and review of the literature.

BACKGROUND: Angiosarcoma (AS) is a rare and malignant tumor which mainly arises in the skin and superficial soft tissue and less frequently in deep soft tissue and bones. Some cases of AS are described in association with vascular and orthopedic devices. Nonetheless, only a few cases of AS around THA are reported in the literature. MATERIALS AND METHODS: We describe five cases of AS arising around total hip arthroplasty who received surgery at our institution (Istituto Ortopedico Rizzoli, Bologna, Italy), and we report the cases described in literature. RESULTS: Foreign bodies such as polyethylene were demonstrated to have a carcinogenic role in animals, but reports of similar cases in humans are rare. Nevertheless, osteolysis induced by wear particles of polyethylene is a frequent event and could induce to desist form considering other more rare causes of osteolysis such as AS. This could be the reason why the diagnosis in several cases was significantly delayed. Common features of these cases could be helpful for doing a prompt diagnosis. The initial presentation is suggestive for septic or aseptic loosening with a massive osteolysis around the cup and/or the stem associated with peculiar aspects as bleeding and loss of weight. Frequently, needle biopsy is negative because foreign-body reaction might have "covered" the most relevant condition of epithelioid AS. CONCLUSIONS: In conclusion in a patient who presents with uncontrollable bleeding, loss of weight and massive osteolysis, AS must be actually considered as possible diagnosis.