[1466] ΒF1 Negative, T-Cell Receptor Gamma Chain Constant Region Positive (TCRGC, Clone γ3.20) Intestinal T-Cell Lymphomas
AL Wilson, SH Swerdlow, U Surti, J Choi, RE Felgar. University of Pittsburgh, Pittsburgh, PA; Children's Hospital, Philadelphia, PA
Background: Enteropathy-associated T-cell lymphoma (EATL) is an intestinal tumor of cytotoxic T-cells, often associated with celiac disease, unique HLA haplotypes and recurrent genetic abnormalities including 9q amplification. The WHO definition includes 2 types, without specific exclusion of a γδ origin. However, it has been suggested that γδ cases should be classified as mucocutaneous γδ T-cell lymphoma.
Design: Clinical, gross, microscopic, flow cytometric (FC) and/or paraffin immunohistochemical phenotype, and EBER staining of 5 small intestine T-cell lymphomas, βF1-negative, with positivity for TCRGC by paraffin IHC (clone γ3.20, Thermo Scientific, Rockford, IL, AJCP 2009;13:820-6), were evaluated, including 1 definite TCR-γδ+ case (FC). 9q31.3 amplification was assessed by FISH (c-abl probe, Vysis).
Results: Patients had no known skin, spleen or other mucocutaneous involvement. 2 had adenopathy on CT. 3/3 had negative BM. 1 had lung involvement 10 mos after diagnosis (only survivor).4/5 patients died of disease (0-10 mos, med 7). All showed transmural invasion, 3 perforated, and a monomorphic infiltrate of intermediate to large cells, with ulceration and extensive mucosal infiltration overlying tumor, and no reactive inflammatory infiltrate. All were CD3, CD7, TIA-1, and TCRGC positive and CD4, CD5, CD25, PD-1, FOXP3, βF1, CD30, ALK-1, and EBER negative, some staining for CD2 (3/5) and granzyme B (1/5). 1 had confirmed TCR-γδ and weak CD103 by FC. Intra-epithelial lymphocytes (IELs) away from tumor were CD3+, TIA-1+, CD8+, with negative CD5 and CD30 in 3 cases evaluated. 4/5 showed 9q polysomies, including case 1.
| Case No/Age/Sex | Known Enteropathy | Multifocal Intestinal Disease | Villous Atrophy (Away from Tumor) | IELs (Away from Tumor) | CD56 | CD8 | TCRγδ (FC) |
| #1 / 31 / M | No | Yes | Yes | Yes | + | - | + |
| #2 / 63 / M | Yes (58 yrs) | No | Yes | Yes | - | + | Equivocal |
| #3 / 90 / F | No | Yes | No | Yes | + | - | N/A |
| #4 / 72 / M | No | Yes | No | Yes | + | - | N/A |
| #5 / 73 / F | No | No | Yes | Yes | - | - | N/A |