BACKGROUND: Although the importance of aberrant DNA methylation in the development of gastric adenocarcinoma has been described, the mechanism of pathogenesis has not been revealed yet. We quantitatively analyzed methylation of four CpG islands and one repetitive DNA element, according to the histologic features of adenocarcinoma with precursor lesions. METHODS: We divided the cases as adenocarcinoma with intestinal type precursors (type A, n=19 cases) and adenocarcinoma with diffuse type precursors (type B, n=19 cases). We micro-dissected tumor cells and matched non-neoplastic gastric mucosa from the hematoxylin and eosin-stained slides. RESULTS: A total of 20 CpG sites of long interspersed nucleotide element-1 (LINE1), RAR-related orphan receptor alpha (RORA), Kruppel-like factor 7 (KLF7), mutL homolog 1 (MLH1), MINT25, and CD133 were analyzed. Methylation was determined by bisulfate-pyro-sequencing, and hypomethylation of LINE1 and CD133 was noted in the tumors, compared to the levels in the non-neoplastic gastric mucosa (p=0.014 and p=0.015, respectively). A statistically different methylation pattern of CpG sites at CD133 and KLF7 was noted only in type B lesions, compared to that in matched non-neoplastic gastric mucosa (p=0.027 and p=0.043, respectively). CONCLUSIONS: Given that aberrant methylation occurs in a relatively early phase of carcinogenesis, different patterns of methylation may determine the carcinoma phenotype. However, further large-scale study is required to clarify the significance of this difference.
Adenocarcinoma ; Adenoma ; Child ; Child, Orphaned ; CpG Islands ; DNA ; DNA Methylation ; Gastric Mucosa ; Hematoxylin ; Humans ; Methylation ; Phenotype ; Stomach

Endometrial carcinomas arising in a bicornuate uterus are rare, only five case of which have been previously reported. We present a case of endometrial cancer arising in a bicornuate uterus, occurring in a 65-year-old woman. Unlike previously reported cases, our case showed mixed endometrial adenocarcinoma and undifferentiated carcinoma in one horn and focal adenocarcinoma in the other. Adequate tissue sampling of both horns is necessary for accurate diagnosis of malignancy in patients with a bicornuate uterus. Physicians should be aware of the possibility of this abnormality in cases when endometrial cancer is suspected but histology fails to confirm.
Adenocarcinoma ; Aged ; Animals ; Carcinoma ; Diagnosis ; Endometrial Neoplasms* ; Female ; Horns ; Humans ; Uterus*