病理学的立場からみた胃粘膜部分切除の評価

Partial Resection of Gastric Mucosa : Evaluation from Pathological Point of View

要旨　粘膜部分切除の適応とその粘膜部分切除組織所見について，病理組織学的観点から若干の考察を行った．ある病変がX線・内視鏡的に発見され，そしてその病変が粘膜部分切除に適していると判断された場合には，その組織診断と治療を兼ねてすぐに粘膜部分切除を行うことなく，まず生検を行ってその病変の質的診断を把握しておくことが必要である．粘膜部分切除標本の断端の組織学的判断は，その断端の人工的組織破壊層の内縁を基準として行う．粘膜下組織浸潤の有無の推定には癌組織発生の観点から，客観的に把握できる癌の所見，存在部位〔幽門腺粘膜領域，腺境界領域，胃底腺粘膜領域〕，大きさ〔1cm以下，1.1～2cm〕，肉眼形態〔陥凹型，隆起型〕，組織型〔未分化型癌，分化型癌〕の4要素から成る粘膜下組織浸潤推定のためのdecision treeを作成し，それに基づいて確率的に判断することが必要である．各病変の胃粘膜部分切除後の対処について述べた．

　Discussions were made from pathological point of view regarding indications of partial resection of gastric mucosa and histological findings of the resected specimen.

　When radiological and endoscopic examination have detected a lesion, it is imperative to make a histological diagnosis by obtaining biopsy specimen before directly going to partial mucosal resection which might lead to histological diagnosis and treatment at once. Stump examination should be made using the inner side of the artificially destructed edge of the partially resected mucosal specimen.

　The degree of submucosal infiltration of cancer should be evaluated according to the following four objective findings based on histogenetic point of view: region 〔antral gland area, intermediate zone, fundic gland area〕, size 〔less than 1 cm, 1.1～2.0 cm〕, macroscopic finding 〔depressed type, elevated type〕, histological findings 〔undifferentiated type, differentiated type〕. These findings can be arrayed in a decision tree to probabilistically estimate submucosal infiltration of cancer (Table 3).

　Finally, discussions were made with respect to management of specific lesions following the partial resection of gastric mucosa.