4型大腸癌と鑑別を要する疾患―腸間膜脂肪織炎とのX線所見上の鑑別

Colorectal Diseases which Need to be Differentiated from Type 4 Advanced Colorectal Cancer: Panniculitis Diagnosed by Barium Enema Study

要旨　4型大腸癌は，病理組織学的にlinitis plastica型胃癌様の進展をするもの（LP型）と，lymphangiosis様の進展をするもの（LA型）に分けられる．注腸X線所見では，粘膜面の凹凸が目立たないもの（平滑型）と，一見して目立つもの（凹凸不整型）に分けられる．自験例7例のうち，手術可能であった4例では，注腸X線で平滑型の2例はLP型であり，凹凸不整型の2例はLA型であった．腸間膜脂肪織炎の注腸X線像の特徴から，凹凸不整型4型大腸癌との鑑別が必要であるものと考えられた．凹凸不整型4型大腸癌の腸間膜脂肪織炎との鑑別点は，粘膜像では不均一な横ひだと不揃いで輪郭不整な顆粒状ないし結節状陰影であり，辺縁像では変形の程度が不均一であり角張った鋸歯状の伸展不良像であった．狭窄部に関しては，4型大腸癌で高度な傾向があったが，同部での鑑別は難しいものと考えられた．

　Histopathologically, type 4 advanced colorectal cancer (CRC4) has been classified into two types; one is Linitis Plastica type (LP) which is known to originate from undifferentiated adenocarcinoma, the other is Lymphangiosis type (LA) which is known to originate from differentiated adenocarcinoma. In this study, we found two types of patterns in double contrast barium enema study of 7 cases studied in our hospital: the smooth-pattern and the irregular pattern. Only four cases fulfilled the criteria for operability. The histological finding of two of the lesions with smooth-pattern was LP and that for the other two, which had an irregular-pattern, was LA.

　Panniculitis which is an inflammatory disease of unknown origin, on the other hand, has characteristic features viewed by double contrast study, such as a serrated shape on the mesenteric side or “saw-tooth appearance” and shortening of the colo-rectum. But these findings are sometimes similar to the findings of LA type of CRC4. We discussed the differences between both diseases based on double contrast barium enema study. The characteristic findings of the LA type of CRC4 are: lack of uniformity of the folds, with an irregular width, presence of nodules of different size and a sharp margin and irregularity of the serrated shape on the mesenteric side of the colon. On the contrary, in Panniculitis the characteristic findings are: regular uniform folds with a regular width, presence of nodules of almost the same size with no shape margin and regularity of the serrated shape on the mesenteric side of the colon.