sm massiveに浸潤した10mm以下大腸癌のX線所見

Radiographic Diagnosis of Massively Invasive Colorectal Cancer Under 10 mm in Size

要旨　対象と方法：20mm以下の大腸sm癌を対象とし，(1)大きさ(10mm以下と11mm以上)と深達度(sm-slight［sm-s］とsm-massive［sm-m］)で4群に分類し，注腸X線所見を比較した．(2)sm-m［≦10mm］群のX線・内視鏡所見を対比した．(3)垂直浸潤距離を側面硬化像の程度で比較した．結果：(1)正面像ではsm-m［≦10mm］群でバリウム斑の陽性率(82.4％)が他の3群(sm-s［≦10mm］群25.0％；sm-s［＞10mm］群26.3％；sm-m［＞10mm］群57.1％)より高く，平滑な辺縁隆起を伴う傾向を認めた．側面像では角状ないし弧状変形をsm-m［≦10mm］群の81.8％，sm-m［＞10mm］群の82.4％に認めたがsm-s［≦10mm］群では11.1％，sm-s［＞10mm］群では21.4％であった．(2)sm-m［≦10mm］群では隆起の性状と陥凹の有無は内視鏡所見との一致率が高かったが，陥凹の性状は乖離する病変が多かった．(3)弧状変形陽性病変の垂直浸潤距離は角状変形陽性ないし変形陰性病変よりも有意に大きかった．以上より，中心陥凹の有無と平滑な辺縁隆起，および側面変形は10mm以下のsm癌でも深部浸潤を示唆する所見と考えられた．

　In order to establish radiographic features of massively invasive colorectal cancer under 10 mm in size, findings obtained by double-contrast barium examinations of large cancers (≦10 mm or ＞ 10 mm) were compared with reference to their depth of invasion (sm-slight ［sm-s］ or sm-massive ［sm-m］) . The incidence of central barium fleck was greater in cancers of the sm-m ≦ 10 mm group than in other groups (p＜0.0001). The incidence of rigidity under profile view was greater in the sm-m ≦ 10 mm group than in the sm-s ≦ 10 mm group and the sm-s ＞ 10 mm group, while there was no difference between the sm-m ≦ 10 mm group and the sm-m ＞ 10 mm group. Cancers in the sm-m ≦ 10 mm group had a smooth surface more frequently than those in the other groups. However, the conditions indicated by central barium flecks were not always concordant with those observed by colonoscopy. It was thus concluded that central barium fleck, smooth protrusion and rigidity are radiographic signs suggestive of massive invasion in colorectal cancers ≦ 10 mm, as well as in larger ones.