Interobserver Variation in the Diagnosis of Gastric Epithelial Dysplasia and Carcinoma between Two Pathologists in Japan and Korea

Abstract

Although the biological potential of gastric epithelial dysplasia (GED) as a precursor of gastric cancer has never been in doubt, the classification of these lesions has been controversial and fraught with marked variations in approach to diagnosis across the world. The complexity of cyto-architectural features has been considered to be of paramount importance for the diagnosis of carcinoma in Japan, while breach of the basement membrane and invasion into the lamina propria has been considered the sine qua non of malignancy and hence a pre-requisite for the diagnosis of cancer in the West. In Korea, although the incidence of gastric cancer is similar to Japan, the diagnostic approach to GED or cancer seems to lie midway between Western and Japanese criteria. In this review, we will discuss the difference in the diagnosis of GED and cancer between two pathologists working in the comprehensive cancer center located in Japan and Korea, one of the most prevalent areas in the world for gastric cancer.

Keywords: Carcinoma; Diagnosis; Dysplasia; Observer variation; Stomach.

Fig. 1

Gastric biopsies diagnosed as erosion by both RK and KMK. Although the pit shows neutrophilic abscesses, there was no epithelial cell necrosis, suggesting erosion rather than neoplasia.

Fig. 2

Gastric biopsies diagnosed as suspected adenocarcinoma by RK. This patient was diagnosed with esophageal squamous cell carcinoma and had received chemo-radiation therapy for 3 months. KMK diagnosed this case as regenerative atypia.

Fig. 3

Gastric biopsies diagnosed as suspicious of adenocarcinoma by KMK. RK diagnosed this case as regenerative atypia because these cells contained Golgi areas in the subapical cytoplasm. KMK thought that those regenerative changes were caused by previous biopsy effects.

Fig. 4

Gastric biopsies diagnosed as adenoma with low-grade dysplasia by both RK and KMK.

Fig. 5

Representative photomicrograph of a very well differentiated intramucosal intestinal type adenocarcinoma without invasion diagnosed by RK.

Fig. 6

Representative photomicrograph of an adenocarcinoma diagnosed by RK, but diagnosed as an adenoma with high-grade dysplasia by KMK.

Fig. 7

Representative photomicrograph of gastric type adenocarcinoma diagnosed by RK, but diagnosed as adenoma with high-grade dysplasia by KMK.

Fig. 8

Adenocarcinoma associated with adenoma diagnosed by RK (A) showing clearly different histology from carcinoma (arrow). Adenocarcinoma arising in adenoma diagnosed by KMK (B) showing a transition from adenoma to carcinoma (arrow).