Epstein-Barr virus (EBV)-induced CD30+ natural killer cell-type malignancy resembling malignant histiocytosis: malignant transformation in chronic active EBV infection associating hypogammaglobulinemia

Natural killer cell-type body cavity lymphoma following chronic active Epstein-Barr virus infection

We describe a 69-year-old female who developed natural killer cell-type body cavity lymphoma following chronic active Epstein-Barr virus (CAEBV) infection. Examination of the patient's pleural effusion revealed large abnormal lymphocytes, which were CD2(+), CD7(+), CD30(+), CD56(+), CD3(-), and CD4(-). No rearrangement of T cell receptor genes was detected. Clonal proliferation of Epstein-Barr virus (EBV)-infected cells in pleural effusion was demonstrated by Southern blot hybridization analysis. Human herpesvirus type-8 (HHV-8) DNA was not detected in these cells. The patient achieved a complete remission with combination chemotherapy. Prior to the clinical onset of lymphoma, high fever of unknown origin had persisted for 21 months. IgG antibodies to EBV-viral capsid antigen and to EBV-early antigens, types D and R were not high (1:160 and less than 1:10, respectively). Two months after the onset of fever, however, retrospective quantitative PCR assay revealed a high EBV DNA load in plasma, indicating that CAEBV infection had been the cause of the patient's recurrent fever. The remarkable features of this case are (i) the development of lymphoma following CAEBV infection that demonstrated a normal pattern of EBV-specific antibodies, (ii) the development of HHV-8-negative body cavity lymphoma, and (iii) the effectiveness of combination chemotherapy.

Primary CD56 + nasal-type T/natural killer-cell subcutaneous panniculitic lymphoma: presentation as haemophagocytic syndrome

Natural killer (NK) cells are large granular lymphocytes that mediate cytotoxic reactions which are not restricted by the major histocompatibility complex. In recent years it has become apparent that a minor proportion of malignant lymphomas expresses an NK-cell phenotype defined by its reactivity with the CD56 antibody. Primary purely cutaneous CD56 + lymphomas have rarely been reported. They share a generally aggressive course and are highly associated with Epstein-Barr virus. We describe a patient with a primary cutaneous nasal-type T/NK-cell lymphoma that presented as a haemophagocytic syndrome and showed an aggressive clinical course.