Virus-associated hemophagocytic syndrome: identification of an immunoproliferative precursor lesion.

Virus-associated hemophagocytic syndrome (VAHS) is a nonneoplastic, generalized histiocytic proliferation with marked hemophagocytosis associated with a systemic viral infection. Histologic studies of lymph nodes usually show lymphoid depletion and histiocytic proliferation. In this report we describe the case of a patient with Epstein-Barr virus-associated VAHS in which initial lymph node biopsy samples showed an immunoproliferative lesion that preceded the usual generalized histiocytic proliferation. This finding suggests that some cases of VAHS may have an immunoproliferative precursor lesion.