High-grade angiosarcoma arising beside a pelvic orthopedic implant: a case report

Introduction: Angiosarcomas are very rare, malignant tumors of the endothelial lining of blood vessels and most present cutaneously, while only 10% present as deep soft tissue angiosarcomas. Literature is sparse regarding secondary deep soft tissue angiosarcoma, especially in cases that have formed surrounding a foreign body such as orthopedic implants. Case: A 59-year-old Caucasian male presented with a 1-year history of occasional headaches and non-intentional weight loss. One month prior to consult, he began to experience progressive pelvic pain on weight-bearing, up to 10/10 in severity, with associated swelling of the left leg. Further diagnostics revealed a hypervascular tumor on the anterior left hemipelvis, directly over his initial pelvic injury and orthopedic implants placed 33 years ago. Clinical Discussion: Biopsy revealed a high-grade angiosarcoma surrounding a stainless-steel 316L reconstruction plate adjacent to a titanium alloy (Ti-6Al-4 V) total hip arthroplasty. NextGen Genome sequence analysis done reveals tier II mutations (potential clinical significance) in the HOXB13 p.G84E and RPS6KB1 genes. Conclusion: Few published cases exist regarding secondary deep soft tissue angiosarcoma, and its peculiar presentation in our case arising at the juncture between two orthopedic implants of different compositions suggests a possible effect of galvanic corrosion, and warrants further study.