Intestinal γδ T-cell lymphomas are most frequently of type II enteropathy-associated T-cell type

Enteropathy-associated T-cell lymphoma includes type I cases and distinctive type II cases that, according to 2008 and 2010 World Health Organization descriptions, are T-cell receptor beta(+). Although T-cell receptor gamma delta enteropathy-associated T-cell lymphomas are reported, it is unknown if they have distinctive features and if they should be categorized as enteropathy-associated T-cell lymphoma or as a mucocutaneous gamma delta T-cell lymphoma. To address these questions, the clinicopathologic, immunophenotypic, molecular, and cytogenetic features of 5 gamma delta-enteropathy-associated T-cell lymphomas were investigated. Only 1 patient had celiac disease and had type I enteropathy-associated T-cell lymphoma, and the others fulfilled the histopathologic criteria for type II enteropathy-associated T-cell lymphoma. All lacked cutaneous involvement. A celiac disease associated HLA type was found in the patient with CD and one of four others. All were T-cell receptor gamma(+), T-cell receptor delta(+), beta F1-, CD3+, CD7+, CD5-, CD4-, and TIA-1+ with variable staining for CD2 (3/5), CD8 (2/5), Granzyme B (1/5), and CD56 (4/5). Fluorescence in situ hybridization demonstrated 9q34 gains in 4 cases, with 9q33-34 gains by single nucleotide polymorphism in 3 of these. Single nucleotide polymorphism analysis also demonstrated gains in 5q34-q35.1/5q35.1 (4/5), 8q24 (3/5), and in 32 other regions in 3 of 5 cases. V delta 1 rearrangements were identified in 4 of 4 cases with documented clonality showing the same clone in normal-appearing distant mucosa (3/3 tested cases). Thus, gamma delta-enteropathy-associated T-cell lymphomas share many features with other enteropathy-associated T-cell lymphoma and are mostly of type II. Their usual nonactivated cytotoxic phenotype and V delta 1 usage are features unlike many other mucocutaneous gamma delta T-cell lymphomas but shared with hepatosplenic T-cell lymphoma. These findings support the conclusion that a gamma delta T-cell origin at extracutaneous sites does not define a specific entity. (C) 2013 Elsevier Inc. All rights reserved.