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.