Peripheral T/NK‐cell lymphoma: a report of the IX^th Workshop of the European Assocation for Haematopathology

Abstract

Most peripheral T/NK cell lymphomas could be categorized as distinct entities as described in the recently proposed WHO classification for lymphoid neoplasms.

Nasal-type extranodal natural killer/T-cell lymphomas: a clinicopathologic and genotypic study of 42 cases in Singapore

“…Nasal-type NK/TCL SB Ng et al genetic features. 2 These tumors almost invariably show a cytotoxic T-or NK-cell phenotype and the prevalence of Epstein-Barr virus relates to the geographical origin of the patient and anatomic sites of involvement, being more frequently positive in the nasal than intestinal or subcutaneous tumors. 6 Disease definition is thus, heavily dependent upon clinical findings, rather than the cell lineage.…”

“…6 Disease definition is thus, heavily dependent upon clinical findings, rather than the cell lineage. 2 These tumors have in common, many clinicopathologic features and similar tumors may show variation in immunophenotype and genotype. As such, many of them cannot be neatly classified according to the recognized categories.…”

“…The prototype, extranodal nasal-type NK-cell lymphomas, has been well described in the last few years. [1][2][3] These lymphomas are postulated to originate from activated NK cells. 4 However, rare cases with identical clinical, histologic and immunohistochemical features may be of true T-cell derivation.…”

“…4 However, rare cases with identical clinical, histologic and immunohistochemical features may be of true T-cell derivation. 2,[5][6][7][8][9] This small proportion of tumors appears to be derived from a unique subset of cytotoxic T cells, known as NK-like or NK1 þ T cell, and shows monoclonally rearranged T-cell receptor genes. [10][11][12] Hence, the term NK/T-cell lymphoma (NK/TCL) is preferred.…”

“…Identical tumors may also be encountered in other extranodal sites, including skin and subcutaneous soft tissue, gastrointestinal tract, and testis. 2,4 These neoplasms often pose difficulties in diagnosis and classification as a result of their rarity, lack of well-established etiologic and genetic data, and very importantly, heterogeneity in their clinical, morphologic and immunophenotypic attributes. Although frequently implicated in the pathogenesis of many human cancers, the role of p53 as a prognostic and predictive factor and its involvement in the pathogenesis of nasal-type NK/TCL is unclear.…”