In:
Histopathology, Wiley, Vol. 73, No. 6 ( 2018-12), p. 1030-1038
Abstract:
Although the neoplastic cells of extranodal natural killer ( NK )/T‐cell lymphoma ( ENKTL ) usually do not express T‐cell antigens, the T‐cell receptor ( TCR ) gene might be rearranged and TCR protein expressed. The aim is to elucidate the expression of the downstream TCR pathway components and their importance in ENKTL . Methods and results We used formalin‐fixed paraffin‐embedded tissues from 91 ENKTL samples to immunohistochemically characterise the expression of TCR pathway components. The following proteins were variably expressed: ZAP 70 (94%; 83/88), GRAP 2/ GADS (68%; 60/88), DOK 2 (42%; 38/90), LCK (35%; 31/88), and ITK (10%; 9/90). When these tumours were classified as being of T lineage (16%), NK lineage (45%), or indeterminate lineage (38%), the GRAP 2/ GADS expression rate was higher in T lineage tumours (versus NK , P = 0.0073; versus indeterminate, P = 0.00082). GRAP 2/ GADS ‐positive NK lineage tumours more frequently expressed DOK 2 ( P = 0.0073), and were more often confined to the nasal areas ( P = 0.014). Furthermore, when these tumours were immunophenotypically classified into a T signature (42%) or NK signature (58%), the expression rates of GRAP 2/ GADS and ITK were higher in T signature tumours ( P = 0.00074 and P = 0.067, respectively), whereas that of LCK was higher in NK ‐signature tumours ( P = 0.10). Conclusions Although some ENTKL cases were polyclonal for TCR rearrangement and others lacked TCR expression, we speculate that the TCR pathway might be functioning in ENKTL s. A T signature versus a NK signature might be better for delineating the physiology of ENKTL than cellular lineage. Furthermore, ITK may represent a potential therapeutic target for patients with ITK ‐expressing tumours.
Type of Medium:
Online Resource
ISSN:
0309-0167
,
1365-2559
DOI:
10.1111/his.2018.73.issue-6
Language:
English
Publisher:
Wiley
Publication Date:
2018
detail.hit.zdb_id:
2006447-0
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