[Clinical polymorphism in Epstein-Barr virus infection].

: Several diseases was associated with Epstein Barr virus (EBV) infection. In the next three cases, the clinical course was unusual . Case I: Polyclonal hypergammaglobulinemia, female 47 years old, she had systemic lupus erythematosus and clinical data of infectious mononucleosis but she evolved to a polyclonal gammopathy with IgM predominantly against EBV. Case II: Demyelinating encephalitis, male, 32 years old with central neurological alterations, IgM antibodies against EBV and demyelinating lesion in magnetic resonance image in brain steam. Case III. Villous leukoplakia, male, 40 years old developed right tonsil tumor. He had IgM antibodies against EBV. The antiviral and immunomodulator treatment (specific for each case) done a satisfactory clinical response in the three patients.