[Diffuse normolipemic xanthomatosis and IgG monoclonal dysglobulinemia].

A 56-year-old man with diffuse cutaneous xanthomatosis had neither mucosal lesions nor diabetes insipidus. Cutaneous lesions were characterised by dermal histiocytic infiltration, without X bodies, associated with Touton's cells and abundant iron deposits. Plasma lipid levels were normal. A lambda G monoclonal dysglobulinemia was present without Bence-Jones proteinuria or myeloma, except for a moderate increase in medullary plasmocytic cell elements. The diagnosis of disseminated xanthomatosis was established, the differential diagnosis from other histiocytic proliferations, particularly diffuse plane xanthoma, being sometimes difficult. The relation between normolipaemic xanthomatosis and dysglobulinemia certainly exists, but no satisfactory pathogenic explanation was possible in this case, in the absence of cryoglobulin, paraprotein antilipoprotein activity, and cutaneous deposits of lipoprotein-paraprotein complexes.