[1305] Extranodal NK/T-Cell Lymphoma, Nasal Type, a Retrospective Study of 50 Cases from the United States.

Shaoying Li, Xiaoli Feng, Pei Lin, Sergej Konoplev, L Jeffrey Medeiros, C Cameron Yin. The University of Texas MD Anderson Cancer Center, Houston

Background: Extranodal NK/T-cell lymphoma, nasal type (ENKTL), is a rare entity endemic in East Asia and Latin America. Although the clinicopathologic features of ENKTL have been well recognized, most data in the literature are derived from Asian countries. There are only case reports and small case series from the western countries.
Design: We retrospectively studied the clinicopathologic features of 50 patients with ENKTL seen at our institution from 1994 to 2010. Survival analysis was performed using the Kaplan-Meier method and compared using the log-rank test.
Results: The study cohort included 30 Caucasians (60%), 13 Hispanics, 4 Asians, and 3 African- Americans (31 men, 19 women, median age at diagnosis 46 years, range 18-88 years). 46 patients (92%) presented with nasal ENKTL, 4 with extranasal disease. 32 (64%) patients with localized nasal disease presented with non-specific sinonasal symptoms. Among cases with clinical data available, 17% (8/48) had anemia, 15% (7/48) had thrombocytopenia and 39% (18/46) had an absolute lymphocyte count (ALC) <1000/μL. 27% (12/45) had elevated serum LDH and 90% (37/41) had elevated β2-microglobulin. 39% (19/49) had stage III/IV disease and 27% (12/45) had an International Prognostic Index (IPI)>2. 23% (11/48) had lymphadenopathy. 13% (6/45) had bone marrow involvement. Histologically, 68% (34/50) of cases showed medium sized cells, 8% (4/50) small cells, 20% (10/50) large cells, and 4% (2/50) mixed small and large cells. 72% (36/50) of cases had angiocentric/angiodestructive growth pattern and 96% (48/50) had necrosis. Immunostains revealed that CD2, CD3, CD4, CD5, CD7, CD8, and CD56 were expressed in 92% (11/12), 94% (44/47), 20% (3/15), 23% (5/22), 67% (8/12), 47% (9/19), and 93% (40/43) of cases, respectively. All cases assessed expressed TIA-1 (n=19) and granzyme B (n=14). In situ hybridization for EBER was positive in 100% of cases. Eight patients received chemotherapy (R-CHOP), 6 had radiation, and 29 had combined radiation and chemotherapy. With a median follow-up of 5.1 years (range, 0.04 to 19.33 years), the median survival was 4.2 years and 5-year overall survival was 45%. Among 15 factors evaluated, ALC<1000/μL, elevated LDH, extranodal sites≥2, stage III/IV disease, IPI>2, and chemotherapy alone were associated with a worse overall survival (P<0.05).
Conclusions: The clinicopathologic and immunophenotypic features of patients with ENKTL from the United States are similar to those from Asian. Compared with Asian population, age, B symptoms, and Hb<11 g/dL are not prognostic factors in our group.
Category: Hematopathology

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 223, Tuesday Morning


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