Metallic implant-associated lymphoma: ALK-negative anaplastic large cell lymphoma associated with total knee replacement arthroplasty.

Metallic implant-associated lymphomas are extremely rare. Only seven cases have been reported in association with knee joint arthroplasty, and all tumors were large B-cell lymphomas. This report is the first case of anaplastic large cell lymphoma occurring after total knee replacement arthroplasty. An 80‑year‑old female patient was admitted because of right knee pain for 2 years. She had undergone total knee replacement arthroplasty 10 years prior. Computed tomography showed an irregular osteolytic lesion in the right lateral femoral condyle, adjacent to the metallic prosthesis. Histologic findings reveal sheets of anaplastic tumor cells that were positive for CD2, CD4, CD5, CD43, and CD30 but negative for CD3, CD20, CD15, and anaplastic lymphoma kinase. Epstein-Barr encoding region in situ hybridization was negative. Analysis of T-cell receptor γ gene rearrangement studies using BIOMED-2-based multiplex polymerase chain reaction confirmed monoclonal T cell proliferation. The woman was finally diagnosed with ALK-negative anaplastic large cell lymphoma.