[Pelvic lymphadenitis after total hip arthroplasty : Mimicking of lymph node metastases in a patient with prostate cancer].

This report describes the case of a 65-year-old patient who underwent radical prostatectomy in our department. Intraoperatively we detected suspicious lymph nodes on the left side. The histopathological examination revealed histiocytosis and foreign body giant cells but no sign of tumor. The enlarged lymph nodes were ascribed to an ipsilateral total hip arthroplasty performed 14 years previously because of progressive coxarthrosis. Lymphadenitis after total hip arthroplasty is frequently observed. Histopathologically and with the use of polarized light microscopy, histiocytosis and wear particles such as titanium, polyethylene, and polyethylene-methylacrylate may be detected. When operating on patients with arthroplasty of a lower limb, particularly those with a total endoprosthesis, the surgeon should bear in mind that changes in lymph node consistency and size do not necessarily indicate tumor involvement or metastases.