| Theme |
Molecular biology of colorectal tumors |
| Title |
Case of colonic cancer of MSS phenotype occurring in sessile serrated adenoma/polyp |
| Author |
Keisuke Kawasaki |
Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, |
| Author |
Makoto Eizuka |
Department of Diagnostic Pathology, Iwate Medical University |
| Author |
Shunichi Yanai |
Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University |
| Author |
Kazuyuki Ishida |
Department of Diagnostic Pathology, Iwate Medical University |
| Author |
Masaki Endo |
Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University / Kaiunbashi Endoscopy Clinic |
| Author |
Shotaro Nakamura |
Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University |
| Author |
Tamotsu Sugai |
Department of Diagnostic Pathology, Iwate Medical University |
| Author |
Takayuki Matsumoto |
Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University |
| [ Summary ] |
A 43-year-old woman underwent a colonoscopy because of positive fecal occult blood findings. Colonoscopy revealed a sessile polypoid lesion with a central depression. Magnifying colonoscopic findings suggested a diagnosis of cancer in a sessile serrated adenoma/polyp (SSA/P). The patient was subsequently treated with endoscopic mucosal resection. Histological examinations exhibited moderately to well differentiated adenocarcinoma in the SSA/P with deep submucosal invasion. Molecular findings revealed that both SSA/P and cancer were positive for BRAF mutations and a high methylation epigenotype. However, an analysis of microsatellite stability revealed that both SSA/P and cancer were microsatellite stable. The patient was diagnosed as having colonic cancer with a MSS phenotype occurring with SSA/P. |