Immunoblastic sarcoma of the central nervous system in a patient with lymphomatoid granulomatosis.

A 26-year-old man with lymphomatoid granulomatosis (LYG) was found at postmortem examination to have an immunoblastic sarcoma involving the central nervous system. Residual evidence of LYG was present only in the lungs at autopsy. Studies for intracellular immunoglobulin utilizing the immunoperoxidase technique showed a marked polyclonal reaction in sections of lymph nodes and occasional cells in the cellular central nervous system tumor that stained for intracellular immunoglobulins (IgG, IgM and both kappa and lambda). This case may represent another example of immunoblastic sarcoma occurring in the presence of an abnormal immune state or proliferation.