Senile EBV+ B-cell lymphoproliferative disorders: a clinicopathologic study of 22 patients.

Twenty-two Epstein-Barr virus-associated B-cell lymphoproliferative disorders (LPDs) without predisposing immunodeficiencies were evaluated clinically and pathologically. All patients were Japanese and negative for anti-human immunodeficiency virus antibody. They were all more than 60 years old with a median age of 75.5 years. Eighteen (82%) patients showed extranodal involvement. Biopsied specimens contained variable numbers of centroblasts, immunoblasts, and Reed-Sternberg-like giant cells often with necrosis and an angiocentric pattern. The 13 cases showing polymorphous composition and inflammatory background were categorized as polymorphic LPD subtype. The other nine cases contained diffuse proliferative lesions of large lymphoid cells and were categorized as large cell lymphoma subtype. Tumor cells expressed CD20 and/or CD79a, and in situ hybridization showed them to be associated with Epstein-Barr virus. LMP1 was detected in all cases and EBNA2 in seven. Eighteen patients initially received combination chemotherapy, and 12 achieved complete remission. However, six patients were refractory to chemotherapy and four patients with complete remission later relapsed. Eight of the 18 patients who received chemotherapy showed an aggressive disease course within a year after the diagnosis. There was a significant difference in prognosis between the group with polymorphic LPDs and the one with large cell lymphomas (p = 0.003). Although the disease profile of the 22 cases was analogous to that of immunodeficiency-associated B-cell LPDs, none of the patients showed evidence of underlying immunodeficiency-related diseases. These findings suggest that Epstein-Barr virus-associated LPD without immunodeficiency mainly occurs in elderly patients. Further investigations are needed to clarify the pathogenesis of this disease and to determine the optimal treatment strategy.