Clinicopathologic and Immunophenotypic Features of Primary Intestinal Extranodal NK/T-Cell Lymphoma, Nasal Type.

Primary intestinal extranodal NK/T-cell lymphoma, nasal type, is an extremely rare type of lymphoma with poor prognosis, and early diagnosis is challenging. Here we have investigated the clinicopathologic features and immunophenotypes of primary intestinal extranodal NK/T cell lymphomas, nasal type, in 10 Chinese patients. Complete staging data showed that 1 patient had stage I disease, 7 had stage II disease, and 2 had stage III disease. Eight of 10 (80%) patients had lymphadenopathy and none had bone marrow involvement. All the patients had a low International Prognostic Index (IPI) score (<3) at presentation. The median age at the time of diagnosis was 37.5 years (range = 24-68 years). All the patients died within 21 months, and the median survival time was 9.5 months (range = 2-21 months). So the conventional IPI and staging system failed to predict the outcome of the patients with the lymphoma. Except for the size of tumor cells, most of the morphologic features of the cases we studied were similar to those involving the midline facial tissue. Immunohistochemical studies showed the expression of cytotoxic markers (100%), CD2 (100%), CD3ε (90%), CD56 (80%), P53 (60%), CD30 (30%), LMP1 (30%), EBNA3A (0%). Nine cases (90%) highly expressed Ki-67. In situ hybridization for Epstein-Barr virus-encoded small RNA was positive in all cases.