T-cell non-Hodgkin's lymphomas can be considered the neoplastic equiva
lents of immunologically functional, site-restricted T lymphocytes. Li
ttle is known about the occurrence and clinical behavior of T-cell lym
phomas that are the neoplastic equivalents of different functional T-c
ell subsets. Here. we investigated the prevalence. preferential site,
immunophenotype, and clinical behavior of the neoplastic equivalents o
f activated cytotoxic T cells (CTLs) in a group of 140 nodal and extra
nodal T-cell lymphomas. Activated CTLs were shown immunohistochemicall
y with a monoclonal antibody against granzyme B, a major constituent o
f the cytotoxic granules of activated T cells. Granzyme B-positive T-c
ell lymphomas were mainly found in mucosa-associated lymphoid tissue (
MALT; nose, 63% of the cases; gastrointestinal tract, 46%; and lung, 3
3%). Granzyme B-positive cases with primary localization in MALT were
more often associated with angioinvasion (P = .005), necrosis (P = .00
2), and histologic characteristics of celiac disease in adjacent mucos
a not involved with lymphoma. Eosinophilia was more often observed in
granzyme B-negative cases (P = .03). Most cases belonged to the pleomo
rphic medium- and large-cell group of the Kiel classification. CD30 ex
pression was more often found in granzyme B-positive lymphomas of MALT
(P = .04), whereas CD56 expression was exclusively found in nasal gra
nzyme B-positive lymphomas. Immuno-phenotypically, most of the cases s
hould be considered as neoplastic equivalents of activated CTLs based
on the presence of T-cell markers on tumor eels. In two cases of nasal
lymphoma, tumor cells probably were the neoplastic counterparts of na
tural killer cells. The prognosis of the granzyme B-positive gastroint
estinal T-cell lymphomas was poor but did not differ from granzyme B-n
egative gastrointestinal T-cell lymphomas. This indicates that, in per
ipheral T-cell lymphomas, site of origin is more important as a progno
stic parameter than derivation of activated CTLs. (C) 1994 by The Amer
ican Society of Hematology.