Natural Killer (NK) cell lymphomas, which include the nasal and the "nasal type" varieties, are defined as angiocentric lymphomas in the revised European American Lymphoma (R.E.A.L.) classification. This group of diseases is rare in the United States and Europe but is more common in Asia and Central America. It is associated with the Epstein-Barr virus (EBV) and its response to treatment and prognosis are usually very poor. The aim of this study was to describe our experience with 13 patients with angiocentric lymphomas seen at The University of Texas M. D. Anderson Cancer Center (UTMDACC) over the last 14 years. Thirteen patients with a diagnosis of nasal NK cell lymphoma were treated at UTMDACC from 1987 to 1999. Eleven patients were treated initially with doxorubicin based chemotherapy with or without radiotherapy. One patient received interferon (IFN)-alpha and vitamin A and another methotrexate, vincristine, L-Asparaginase, and radiotherapy. The median age was 44 years (range 15-76); there were four women and nine men. All patients presented with local disease involving the sinonasal region. Typical immunophenotypes expressing CD2+, CD3- and CD56+ surface markers as well as non rearrangement of T-receptors were present in all patients. Eight patients (62%) responded to therapy; six (46%) with complete response (CR) and two (16%) with partial response (PR). Five patients (38%) were alive, four with no evidence of disease (NED) at 1, 2, 3, and 9 years after treatment, and one patient was alive with disease (AWD) at the time of publication. One patient died while in CR from complications from allogeneic bone marrow transplant. Six patients had disease progression to extranodal sites including: testis (2), central nervous system (2), lung (1), bone marrow (2), liver (2), peripheral blood (2), and skin (2). In conclusion, the response to doxorubicin-containing regimens is inferior to that of patients with other non-Hodgkin's lymphomas and similar prognostic factors. Because the disease is associated with EBV virus in 90%-100% of the cases and the prognosis is poor, innovative therapies should be tried including immunotherapy that targets the expression of EBV by the tumor with or without myeloablative procedures.