INTESTINE Vol.19 No.3(6)

Series
Title A case of adenocarcinoma with serrated lesion (microvesicular hyperplastic polyp)
Publish Date 2015/05
Author Yoshihito Tanaka Department of Gastroenterology, Akita Red Cross Hospital
Author Hiro-o Yamano Department of Gastroenterology, Akita Red Cross Hospital
Author Noriyuki Uesugi Department of Molecular Diagnostic Pathology, Iwate Medical University School of Medicine
Author Tamotsu Sugai Department of Molecular Diagnostic Pathology, Iwate Medical University School of Medicine
Author Eiichiro Yamamoto Department of Molecular Biology, Sapporo Medical University
Author Hiromu Suzuki Department of Molecular Biology, Sapporo Medical University
[ Summary ] The patient was a 70-year-old man. He had a laterally spreading tumor (LST) in the transverse colon, suspected to be a hyperplastic polyp, in November 2009. A surface protrusion appeared in the same lesion in March 2011. This evolved in a protruded lesion within the LST in October 2012. Magnifying endoscopy indicated a Type V pit pattern in the protruded part of the lesion. Type II pit patterns were observed in the LST part of the lesion. From these findings, we diagnosed this lesion as carcinoma accompanied by a hyperplastic polyp. Surgical resection was performed. The histological diagnosis was of adenocarcinoma with microvesicular hyperplasic polyp (MVHP). Carcinoma component : tub1>tub2>pap, pSS, ly2, v1, pPM0, pDM0, pN0. We performed analysis of genetic markers. We did not recognize BRAF or kras mutation in both the carcinoma and MVHP areas. We identified CpG island hypermethylation in both carcinoma and MVHP areas, but methylation of hMLH1 was found only in the carcinoma. This lesion was defined as a colon cancer with microsatellite instability.
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