[Waldenström's disease and periarteritis nodosa: fortuitous association? (author's transl)].

A 48-year-old-woman had simultaneously a peri-arteritis nodosa (PAN) and a Waldenström disease. PAN's symptoms were quickly regressive, neuropathy excepted (with slowness) under treatment by cyclophosphamide and prednisone. Hemopathy is now stabilized. Such a pathological association is exceptional (2 other cases in literature). Is it accidental? No cryoglobulinaemia or circulating immune-complexes or HBS antigen were found. Immunofluorescence study of arteriolar lesions in muscle showed a polyclonal fixation in inflammatory granuloma and monoclonal (IgM lambda) on endothelial side. Passive deposit is not excluded, because research of specific activity of IgM lambda (against fibrin or endothelial cells) was negative. Waldenström's disease has probably facilitated apparition of necrotizing angeitis but mechanism is not proved.