Infectious mononucleosis mimicking a B cell immunoblastic lymphoma associated with an abnormality in regulatory T...

An elderly woman is described with infectious mononucleosis in whom cervical node biopsy was interpreted as showing immunoblastic lymphoma. Concomitant reactive lymphocytosis, Epstein-Barr virus serologic results consistent with an acute infection, and demonstration of polyclonal B cell infiltration of other tissues argued against intervention. Defective in vitro T cell responses were demonstrated during the acute phase of Epstein-Barr virus infection. Infectious mononucleosis has rarely been reported as mimicking a non-Hodgkin's lymphoma. At 18 months, our patient's course has been typical for infectious mononucleosis with no evidence of disseminated malignancy.