外科手術症例から振り返る早期胃癌の随伴0IIb範囲診断

A Clinicopathological Study of the Accompanying Type 0IIb in Early Gastric Cancer

要旨　2001年から2008年までに福井県立病院外科で開腹手術した早期胃癌651例のうち，随伴0IIbとした症例は53例（8.1％）であった．非随伴群と比較すると，随伴0IIb群での男女比は，7.83：1と男性が多く，癌巣全体の平均腫瘍径は5.1cmであり，非随伴群の2.7cmより大きかった．リンパ節転移は随伴0IIb群の13.2％が陽性であり，非随伴群の4.2％より多かった．組織学的断端陽性は随伴0IIb群の3.8％に認め，非随伴群の0.5％より多かった．組織型を分化・未分化の2つに分けた場合でも，両組織型において随伴0IIb群で男性が多く，腫瘍径が大きかった．未分化型癌随伴0IIb群においてはSM癌比率が低いにもかかわらず，リンパ節転移率が高かった．分化型癌で随伴0IIb群は多発癌が多かった．随伴0IIb部分の平均径は2.1cmで，全例粘膜内浸潤で，主たる進展は前後壁方向に多かった．主病変部と随伴0IIb部分の境界を検討すると，明瞭なものが21例，不明瞭なものが32例，明瞭なものには隆起型が多く，周囲粘膜に腸上皮化生が存在すると境界が不明瞭となることが多かった．

　Of 651 early-stage gastric cancer cases, 53（8.1％）had concomitant 0IIb lesions（0IIb group）. Comparison of the 0IIb group vs. the non 0IIb group showed the following several characteristics. The 0IIb group had a higher percentage of males 7.83 : 1. ; larger mean tumor diameter was seen in the 0IIb group（5.1cm vs. 2.7cm）; there were more frequent case of lymph node metastasis in the 0IIb group（13.2％ vs. 4.2％）; and a higher frequency of microscopic cancer-positive stumps were observed in the 0IIb than in the non 0IIb group（3.8％ vs. 0.5％）. Further, histological types were classified into two types of differentiated and undifferentiated, and still the number of males and mean tumor diameter was larger in the 0IIb group in both histological types. A lower percentage of cases with submucosal（SM）cancer and higher percentage of cases with lymph node metastasis was found in the undifferentiated 0IIb group. Multiple carcinoma was more frequent in the differentiated 0IIb group. The concomitant 0IIb lesions had a mean diameter of 2.1cm, all showing submucosal invasion, and frequently extending mainly to the horizontal axis. Of the 53 cases, 21 showed a clear boundary between the main lesion and the concomitant 0IIb lesion, while in 32 cases the boundary was unclear. The protruding type was more common in the former group, and unclear boundary was frequently associated with intestinal metaplasia in the surrounding mucosa.