LANGERHANS CELL HISTIOCYTOSIS AND ERDHEIM -CHESTER-DISEASE - PROBABLYAN UNFORTUITOUS ASSOCIATION

Background. Erdheim Chester disease (MEC) is a rare non-Langerhans cel l histiocytosis characterized by multi-visceral involvement. We report a case of MEC associated with Langerhans cell histiocytosis (HCL). Ca se report. A 46-year-old women presented skin and vulvar localization of HCL associated with typical MEC bone involvement. Despite chemother apy (vinblastine) and prednisone, the disease progressed to involve th e central nervous system, leading to fatal outcome. Post-mortem examin ation showed HCL in skin, MEC in bones and central nervous system, and intermediate histiocytic: proliferation in the encephalon. Discussion . Usually, MEC and HCL are considered as distinct entities. MEC is cha racterized by a xanthogranulomatous proliferation of CD 68 + foamy his tiocytes nested in fibrosis, and HCL by a proliferation of PS 100 + an d CD1a + Langerhans cells. However, our observation, as well as previo us reports, suggests that MEC is part of the HCL spectrum.