ENDOSCOPIC ULTRASONOGRAPHY IN THE DIAGNOSIS OF THE DEPTH OF GASTRIC CANCEROUS INVASION; DIFFERENTIAL DIAGNOSIS BETWEEN CANCEROUS INVASION AND FIBROSIS OF THE CO-EXISTING ULCER

Abstract

Diagnostic method for the depth of gastric cancerous invasion using endoscopic ultrasonograhy (EUS) was studied, especially in the cases of differential diagnosis between cancerous invasion and fibrosis of the co-existing ulcer. 65 cases of IIc+III and IIc + (III) type early gastric cancer and depressed type like advanced cancer were analysed histopathologically. Fibrosis of the co-existing ulcer in m-cancer group, the invasion of which is limited to the mucosa, always showed a fanshaped propagation towards the outside of the stomach. Fibrosis of the co-existing ulcer in sm-cancer group, the invasion of which spread to the submucosa, except microinvasion cases, showed irregular arch-shaped propagation. In the depressed type like advanced cancer group that invaded ss-s (subserosa-serosa) layer without ul-III, IV ulceration, thickening of pm (proper muscle) layer and hump of the serosa was observed. In the depressed type like advanced group that invaded pm or ss-s layer with ul-III ulceration, thickening of sm-pm layer and hump of the serosa was observed. Diagnosis on the depth of cancerous invasion using the ultrasonographic pattern analysis was clinically attemped, the correct diagnostic rate for the ulceration-complicated early gastric cancer group was 78.4% (29/37 cases), while that for the non-complicated group was 88.9% (64/72 cases). Moreover, the result of 76.2% (16/21 cases) for the depressed type like advanced gastric cancer group was obtained. However, a poor correct diagnostic rate of 60.0% (9/15 cases) was obtained for the IIc + III sm-cancer group. That is, minute intra- or para-fibrosis invasion was not detected ultrasonographically. The correct diagnostic rates for lesions of the aeterior wall and the angle of the stomach were 70.6% (24/34 cases) and 78.0% (32/ 41 cases), respectively, which were poor when compared to the others. There was a tendency for the results to be poor as the diameter was increased up to 6 cm in diameter. It was found that a large portion of misdiagnosed cases were grouped under 3 × 2 mm or below of microinvasion, which was thought to be the clinical limit at this stage. It is concluded that the diagnosis on the depth of cancerous invasion using the ultrasonographic pattern analysis was useful especially in the case of ulceration-complicated gastric cancer.