経過を追えたSSA/Pの癌化例

The SSA/P Associated Cancer Which was Able to Follow up, Report of a Case

要旨●患者は60歳代，男性．2012年12月の大腸内視鏡検査で，盲腸底部に径20mm大の扁平隆起性病変を認めた．拡大観察では，開II型と伸II型があり，SSA/P由来の腫瘍と思われた．4か月後の再検で，病変中央部に陥凹面を認め，NBI観察では，surface patternは保たれていたが，病変辺縁に通常より口径の太い血管を認め，pit patternは一部V_I型軽度不整を疑う所見も認めた．生検でGroup 4であり，内視鏡治療困難な部位のため，手術が施行された．径20×18mm，中分化型腺癌，pSM 800μm，INFβ，ly2，v0，No.202（＋）であった．病変の局在が原因で手術となったが，結果としてリンパ節転移まで来しており，SSA/P由来の癌の進展速度が急速である可能性が示唆された症例と考えられた．

　In December 2012, a flat, elevated, 20mm diameter lesion was observed in the lower end of the cecum in a 60-year-old male by colonoscopy. Magnifying observations showed a mixture of open II and long II type pit pattern, which suggested a SSA/P（sessile serrated adenoma/polyp）tumor. After 4 months, the lesion center was depressed. Observations using narrow band imaging showed that the surface pattern had not changed, and there were thick vessels near the lesion margins. We considered that the endoscopic treatment was difficult because the locations is bad, we selected surgery. A 20×18mm diameter tumor was found, which was identified as a moderately differentiated tubular adenocarcinoma with serrated adenoma of tub2, pSM（800μm）, INFβ, ly2, v0, No.202（＋）type. The surgery was performed because the location was poor, and the tumor had metastasized to the lymph nodes. Surgery should be considered in cases which suggest a potential rapid growth rate of the cancer from an SSA/P tumor.