Lymphomatoid gastropathy: a distinct clinicopathologic entity of self-limited pseudomalignant NK-cell proliferation.
Diagnostic errors in distinguishing between malignant and reactive processes can cause serious clinical consequences. We report 10 cases of unrecognized self-limited natural killer-cell proliferation in the stomach, designated as lymphomatoid gastropathy (LyGa). This study included 5 men and 5 women (age, 46-75 years) without any gastric symptoms. Gastroscopy showed elevated lesion(s) (diameter, ∼ 1 cm). Histologically, medium-sized to large atypical cells diffusely infiltrated the lamina propria and, occasionally, the glandular epithelium. The cells were CD2(+/-), sCD3(-), cCD3(+), CD4(-), CD5(-), CD7(+), CD8(-), CD16(-), CD20(-), CD45(+), CD56(+), CD117(-), CD158a(-), CD161(-), T cell-restricted intracellular antigen-1(+), granzyme B(+), perforin(+), Epstein-Barr early RNA(-), T-cell receptor αβ(-), and T-cell receptor γδ(-). Analysis of the 16 specimens biopsied from 10 patients led to a diagnosis of lymphoma or suspected lymphoma in 11 specimens, gastritis for 1 specimen, adenocarcinoma for 1 specimen, and LyGa or suspected LyGa for 3 specimens. Most lesions underwent self-regression. Three cases relapsed, but none of the patients died. According to conventional histopathologic criteria, LyGa is probably diagnosed as lymphoma, especially as extranodal natural killer/T-cell lymphoma, nasal type. However, LyGa is recognized as a pseudomalignant process because of its clinical characteristics. The concept of LyGa should be well recognized.
Takeuchi
Kengo
K
The Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan. kentakeuchi-tky@umin.net
Yokoyama
Masahiro
M
Ishizawa
Shin
S
Terui
Yasuhito
Y
Nomura
Kimie
K
Marutsuka
Kousuke
K
Nunomura
Maki
M
Fukushima
Noriyasu
N
Yagyuu
Takahiro
T
Nakamine
Hirokazu
H
Akiyama
Futoshi
F
Hoshi
Kazuei
K
Matsue
Kosei
K
Hatake
Kiyohiko
K
Oshimi
Kazuo
K
D000368:Aged; D015153:Blotting, Western; D020031:Epstein-Barr Virus Infections / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D015321:Gene Rearrangement; D004854:Herpesvirus 4, Human / Q000235:genetics; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D017403:In Situ Hybridization; D007694:Killer Cells, Natural / Q000378:metabolism / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000378:metabolism / Q000473:pathology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000378:metabolism; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013272:Stomach Diseases / Q000378:metabolism / Q000473:pathology* / Q000821:virology
D012333:RNA, Messenger; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta