Clinicopathological features of early gastric cancers arising in <i>Helicobacter pylori</i> uninfected patients
Chiko Sato, Kingo Hirasawa, Yoko Tateishi, Yuichiro Ozeki, Atsushi Sawada, Ryosuke Ikeda, Takehide Fukuchi, Masafumi Nishio, Ryosuke Kobayashi, Makomo Makazu, Hiroaki Kaneko, Yoshiaki Inayama, Shin Maeda
Abstract
BACKGROUND: uninfected patients though rarely reported, is a concern to be addressed and needs elucidation of its clinicopathological features. AIM: -uninfected patients. METHODS: -IgG antibody, urease breath test, rapid urease test, and microscopic examination. RESULTS: The frequency of HpUIGC was 1.2% (30/2462) for the patients in our study. The study included 19 males and 11 females with a mean age of 59 years. The location of the stomach lesions was divided into three sections; upper third (U), middle third (M), lower third (L). Of the 30 lesions, 15 were U, 1 was M, and 14 were L. Morphologically, 17 lesions were protruded and flat elevated type (0-I, 0-IIa, 0-IIa + IIc), and 13 lesions were flat and depressed type (0-IIb, 0-IIc). The median tumor diameter was 8 mm (range 2-98 mm). Histological analysis revealed that 22 lesions (73.3%) were differentiated type.The HpUIGC lesions were classified into fundic gland type adenocarcinoma (7 cases), foveolar type well-differentiated adenocarcinoma (8 cases), intestinal phenotype adenocarcinoma (7 cases), and pure signet-ring cell carcinoma (8 cases). Among 30 HpUIGCs, 24 lesions (80%) were limited to the mucosa; wherein, the remaining 6 lesions showed submucosal invasion. One of the submucosal invasive lesions showed more than 500 μm invasion. The mucin phenotype analysis identified 7 HpUIGC with intestinal phenotype and 23 with gastric phenotype. CONCLUSION: We elucidated the clinicopathological characteristics of HpUIGC, revealing recognition not only undifferentiated-type but also differentiated-type. In addition, intestinal phenotype tumors were also observed and could be an important tip.