linitis plastica型胃癌早期診断へのアプローチ―臨床の立場から

Clinical Approach to Early Detection of Linitis Plastica Type Gastric Cancer

要旨　linitis plastica型胃癌（以下，LP）の早期診断は，その原発巣を探し出すことにあるが，発育経過中に原発巣に潰瘍ができ，ときに瘢痕化し，また周囲粘膜を這ってびらんを形成する．それゆえLPの早い時期のうちに発見しうる可能性も多い．胃底腺領域（以下，F領域）の小さなⅡcあるいはⅡbをすべて発見し刈り取ることができれば，F領域に発生した胃癌はほとんどm癌のうちに発見されることになり，LPはなくなるはずである．その発見はかなり難しいが，発見の糸口をつかむことができた．固定集団の長期逐年検診からみると，Borrmann4型，LPとも著しく減少している．早期癌発見の割合が増加し，それにつれて未分化型早期癌，F領域早期癌発見の割合が増加したためと思われるが，なお早期発見の難しいと思われるものが発見癌120例中3例（2.5％）あり，特殊なLP，Borrmann 4型，Borrmann 3型であった．

　Purpose of this paper is to find the clue to detect early gastric cancer which would lead to linitis plastica type advanced gastric cancer (LP). The main focus on detection of early stage of LP is to find out primary lesions. During development of LP, primary lesions form ulcers and may accompany scars or erosions which cancer cells may invade to mucosa around primary lesions. Therefore, these primary lesions may lead us to find LP in early stage. If we could find type Ⅱc or Ⅱb early gastric cancers on fundus gland area and remove them surgically, we might be able to get rid of LP, because invasion of gastric cancer cells may be confined to mucosa. We should find LP within a stage of mucosal carcinoma.

　It would be difficult to detect early stage of LP, but we are able to find a key to it. According to a long term prospective study on a fixed population, the incidence of Borrmann type 4 advanced gastric cancer or LP has been markedly reduced. As the proportion of early gastric cancer in total gastric cancer has been increased, we suspect this trend might also be true in undifferentiated gastric cancer and LP. We have 120 cases of LP, there were 3 cases (2.5%) which we thought were difficult to diagnose in early stage. They were special cases of LP, Borrmann type 3 and type 4 gastric cancer.