RT Journal Article SR Electronic T1 Adverse reactions to metal debris: histopathological features of periprosthetic soft tissue reactions seen in association with failed metal on metal hip arthroplasties JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 409 OP 418 DO 10.1136/jclinpath-2011-200398 VO 65 IS 5 A1 Sonali Natu A1 Raghavendra Prasad Sidaginamale A1 Jamshid Gandhi A1 David J Langton A1 Antoni V F Nargol YR 2012 UL http://jcp.bmj.com/content/65/5/409.abstract AB Aim To describe the histopathology of localised adverse reactions to metal debris (ARMD) seen in association with failed metal on metal (MoM) hip arthroplasties. The nature of aseptic lymphocytic vasculitis associated lesion (ALVAL) is investigated.Methods Periprosthetic soft tissues biopsied at time of revision from failed MoM hip arthroplasties from January 2007 to March 2011 were analysed. The inflammatory cell response was categorised into perivascular lymphocytic cuffing (ALVAL), lymphoid aggregate formation with or without germinal centres, metallosis characterised by sheets of macrophages with intracytoplasmic metallic debris and well-defined granulomas.Results 123 patient samples were analysed, 36 males (29.2%) and 87 females (70.8%). Three cases showing complete tissue necrosis were excluded. Patients were reviewed between 3.27 to 69.6 months postarthroplasty, with an average of 30.92 months. 103 cases (85.8%) showed ALVAL, 18 cases also showed well-defined granulomas. Of the 103 cases with ALVAL, 60 cases also showed a diffuse chronic lymphocytic synovitis, and 40 cases showed lymphoid aggregates with germinal centres. 17 cases (14.2%) showed pure metallosis. Small vessels showing ALVAL expressed peripheral node addressin.Conclusions ARMD is a spectrum of changes comprising of pure metallosis, ALVAL and granulomatous inflammation. ALVAL, a distinctive inflammatory response seen in ARMD, is a precursor of lymphoid neogenesis. Lymphoid neogenesis documented in a variety of chronic inflammatory conditions most probably contributes to tissue necrosis and prosthetic failure seen in MoM hip arthroplasties. The role of vascular changes in contributing to necrosis is unclear at this stage.