title: A case of lymphomatoid gastropathy: a self-limited pseudomalignant natural killer (NK)-cell proliferative disease mimicking NK/T-cell lymphomas.
abstract: Natural killer (NK)/T-cell lymphomas exhibit aggressive tumor behavior and have a poor prognosis. Recently, self-limited pseudomalignant NK-cell proliferative disorders of the stomach mimicking NK/T-cell lymphomas have been recognized. We report a rare case of lymphomatoid gastropathy in a 71-year-old female. The patient underwent esophagogastroduodenoscopy (EGD) because of slight epigastric discomfort which revealed a 10-mm, reddish, flat elevation with erosion on the posterior wall of the lower gastric body. Histological examination of biopsy specimens showed atypical NK/T cell infiltration with cytoplasmic CD3+, CD4-, CD5-, CD7+, CD8-, CD16-, CD20-, CD56+, CD68-, CD117-, MPO-, TIA1+, and granzyme B+. Epstein-Barr virus-encoded RNA in situ hybridization was negative. Three months later, repeated endoscopic examination surprisingly revealed spontaneous regression of the lesion without any treatment. It is important that endoscopists consider this rare entity in the differential diagnosis, and excessive treatment should be avoided.
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan. yoko.ishibashi@dream.com.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ishibashi
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Matsuzono
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Yokoyama
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Ohara
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan.
authors.forename: Nozomu
authors.initials: N
authors.lastname: Sugai
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Seki
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan.
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Miura
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Fujita
authors.affiliation: Department of Gastroenterology, KKR Sapporo Medical Center, 3-40, 1-jo, 6-chome, Toyohira-ku, Sapporo, 062-0931, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Suzuki
authors.affiliation: Department of Pathology, KKR Sapporo Medical Center, Sapporo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujisawa
authors.affiliation: Department of Pathology, KKR Sapporo Medical Center, Sapporo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hatanaka
keywords: Helicobacter pylori; Lymphomatoid gastropathy; NK-cell enteropathy; NK/T-cell lymphoma nasal type; Stomach