[Erdheim-Chester disease: a non-Langerhans cell histiocytosis. A clinical-case and review of the literature].

We make a retrospective evaluation of clinical and radiologic features, treatment, and outcome of Erdheim-Chester disease, a rare non-Langerhans cell histiocytosis. We report a case of Erdheim-Chester disease and review 60 cases from the literature. These cases are consider to have Erdheim-Chester disease when they have either typical bone radiographs (symmetrical long bones osteosclerosis) and/or histologic criteria disclosing histiocytic infiltration with distinctive immunohistochemical phenotype of the non-Langerhans cell histiocytes with positive staining for CD68 and negative staining for S-100 protein and CD1a. Our patient undergoes chemiotherapy according to the LCH-II stratification and therapy plan (Vinblastine, Etoposide and Prednisone) and thereafter receives Carboplatin and Etoposide, and Somatostatin. She is alive and clinically well 33 months after onset of symptoms and the lesions don't appear to progress at imaging examinations. In conclusion, Erdheim-Chester disease may be confused with Langerhans cell histiocytosis as it sometimes shares the same clinical (exophthalmos, diabetes insipidus) or radiologic (osteolytic lesions) findings. However, the characteristics radiological pattern of Erdheim-Chester disease together the immunohistochemical phenotype of hystiocytic infiltration supports the theory that Erdheim-Chester disease is a unique disease entity distinct.