[1181] Most Primary Intestinal T and NK/T-Cell Lymphoma in Taiwan Are Unspecified Peripheral T-Cell Lymphomas Showing Cytotoxic Phenotype, and NK Lineage and Perforation Predict Poor Survival

S-S Chuang, S-T Chang, W-T Huang, P-P Hsieh, M-H Tsou, Y-C Jung. Chi-Mei Medical Center, Tainan, Taiwan; Chang Gung Memorial Hospital-Kaohsiung, Kaohsiung, Taiwan; Veterans General Hospital-Kaohsiung, Kaohsiung, Taiwan; Koo Foundation Sun Yat-Sen Cancer Center, Taipei, Taiwan; Sin-Lau Christian Hospital, Tainan, Taiwan

Background: Most primary intestinal T and NK-cell lymphomas (ITNKL) in the West are enteropathy-associated T-cell lymphomas (EATL), a rare complication of celiac disease (CD) which is common in the West but is extremely rare in the East including Taiwan. Type A EATL is definitely CD-associated, with typical HLA types and serology, and large tumor cells that are usually CD56-negative. The rare type B variant is probably unrelated to CD, and the small tumor cells usually express CD56.
Design: We retrospectively collected 22 cases of ITNKL, the largest series from Taiwan, for a clinicopathological and molecular study.
Results: There were 14 males and 8 females with a median age of 56. Seventeen (77%) presented with perforation. Seventeen (77%) patients were at stage I, and 5 (23%) at stage II. Eighteen (82%) tumors were of T cell lineage and 4 (18%), NK cell. The tumor cells in 18/22 (82%) cases were small to medium-sized including 15/18 T and 3/4 NK cell tumors. The T-cell tumors included 16 unspecified peripheral T-cell lymphomas (uPTL) without enteropathy and 2 with features of enteropathy mimicking Western type B EATL (Chuang SS et al. Histopathology 2008; 53: 234). These 18 tumors expressed CD3 (100%), T-cell intracellular antigen-1 (89%), CD7 and CD56 (83%), CD8 and granzyme B (67%), CD2 (56%), and CD5 (6%), but not CD4. All tumors expressed at least one cytotoxic marker. Seven (39%) tumors were positive for EBV-encoded mRNA (EBER). All but two tumors with poor DNA quality were clonal for T-cell receptor (TCR) gene rearrangement. The 4 NK cell lymphomas expressed at least one cytotoxic marker. All 4 tumors were positive for EBER and were polyclonal for TCR. Three of these expressed CD56. The 1-yr and 2-yr survival rates of these 22 patients were at 38% and 21%, respectively. NK cell lineage (log rank test; P = 0.012) and perforation (P = 0.026) were associated with poor survival.
Conclusions: ITNKL in Taiwan is predominately uPTL, with a high frequency of perforation at presentation, lack of association with CD, small to medium tumor cells expressing cytotoxic marker, CD56 and EBER, and poor prognosis. Furthermore, NK cell lineage and perforation predict poor prognosis.
Category: Hematopathology

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 190, Wednesday Morning