Epstein-Barr virus-associated T/natural killer-cell lymphomas in the elderly: the first consensus meeting in Kofu 2013.

From a clinicopathological conference on nine elderly patients with Epstein-Barr virus (EBV)-associated T/natural killer (NK)-cell lymphoma, we have addressed the patients' backgrounds, clinical manifestations, histopathological findings, cytogenesis, complications and prognoses. Among these elderly patients (>65 years old), seven patients had extranodal NK/T-cell lymphoma, nasal type (ENKL) with an NK-cell phenotype, and two patients had EBV(+) T-cell lymphomas or lymphoproliferative disorders (LPD) with cutaneous lesions mimicking pityriasis lichenoides et varioliformis acuta (PLEVA) or hydroa vacciniforme (HV). No patients had a previous episode of EBV-related symptoms such as infectious mononucleosis, chronic active EBV infection, HV or hypersensitivity to mosquito bites. Elderly patients with ENKL may show the centroblastoid variant. EBV(+) CD8(+) CD56(+/-) lymphocytes may be responsible for the development of PLEVA or HV-like cutaneous lesions in the elderly.