[1311] Extranodal Natural Killer/T-Cell Lymphomas in Jujuy North-West Argentina: A Clinic-Pathologic Study of 40 Cases.

Oscar Marin. Pablo Soria Hospital, S.S. Jujuy, Argentina

Background: In Argentina the incidence of Extranodal Natural Killer / T-cell Lymphomas are unknown. Our Hospital register cases suspicious of NK/T-cell lymphomas but without immunohistochemical studies. Our State located near Bolivia had around 600.000 people mainly Amerindians ethnically related with Asian people that clear overcame people from European ancestry. In many aspects lymphomas in Jujuy mimics the features of lymphomas in Asian countries including low incidence of Follicular Lymphomas and prevalence of T-cell Lymphomas including and Adult T-cell lymphoma (ATLL) HTLV-1 associated and a few cases of NK/T-cell lymphomas are reported.
Design: Paraffin embedded material was obtain for immunohistochemestry and in-situ hibridization in 33/40 cases suspicious of nasal type lymphomas. Biopsies were fixed in a solution of Formalin 10%, and routinely studied by Haematoxylin-Eosin, Giemsa, and P.A.S. stains in sections of the 3 micrometers. The lesions were examined for necrosis, angiocentric / angioinvasive growth and cytological features. Paraffin-immunohistochemistry (pIHC): ABC method with antibodies against CD3, CD4, CD5, CD7,CD8, D30, CD56, CD20, CD79a, TdT, TIA1, Perforin, granzime-B, LMP-1, bcl-2, CD30, p53 and Bcl-10. In-situ hybridization (ISH) of EBV-encoded small nuclear early region-1 (EBER-1).
Results: 32/33 cases are NK/T-cell nasal type lymphoma, 1 case a cytotoxic T-cell lymphoma without EBV signal by ISH and negative for CD56. The age range is 07-84 years old. 28 patients are males and 5 females. Nasal lymphomas in 14 cases and 18 are extranasal including palate, skin, soft tissue, eyelid and testis. The clinical outcome was very aggressive. The morphology show necrosis, angiodestruction and a cytological range from small polymorphic cells to median and large size cells mainly with clear cytoplasm and occasional large, bizarre cells. IMMUNOPHENOTYPIC STUDY: In 32/33 the immunophenotype make a definitive diagnosis of NK/T-cell lymphoma with EBV+ by ISH-EBER-1 or LMP-1. 9/19 p53+, 9/16 Bcl-10+, Ki-67 show high mitotic index.
Conclusions: Our cases of NK/T-cell lymphomas also show a clear association of EBV, aggressive outcome and because the majority of cases are Amerindians living isolated near the Andes and genetic related to Asian but also with people from Bolivia and Peru a strong racial predisposition is suggested.
Category: Hematopathology

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 222, Tuesday Morning

 

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