Tissue reactions to wear debris in prosthetic arthroplasties: diagnostic problems. Two cases report

We report two cases of tissue reactions to wear debris after large joint pr ostheses. In the first case, a septic loosening of a hip arthroplasty was s uspected after emergence of an inguinal mass. In the second case, a patient with loose hip prosthesis had surgery for a prostatic adenocarcinoma and p elvic lymph nodes were discovered during surgery. They were first suspected to be metastatic carcinoma. These two diagnostic problems were resolved by histology which revealed sinusal histiocytic reaction to wear debris. The peculiar sign of this reaction is the presence of birefrengent components s uch as polyethylene seen with polarized light. These problems will become m ore frequent in the future because of the increasing number of elderly pati ents who have had hip replacement and will undergo surgery for pelvic cance r. A close medico-surgical collaboration should help pathologists in such c ases.