Histological Diagnosis of Gastric Dysplasia/Intra-Epithelial Neoplasia and Intramucosal Carcinoma

By years 90 differences between Japanese and Western pathologists in diagnosing gastric dysplasia and carcinoma have represented reason to dispute [1].

In Japan the diagnosis of gastric carcinoma is based exclusively on cytological and architectural features, while Western pathologists define carcinomas only invasive tumours (infiltration of the lamina propria).

In 1998 the Vienna Classification was introduced in order to reach a diagnostic higher reproducibility and standardization [2]. The most important advantage of the Vienna Classification is that the various categories are associated with different recommendations for further therapeutic indications. Moreover, since the introduction of it, in the contemporary WHO Classification (2000) the term “dysplasia” was replaced by the category “intra-epithelial neoplasia”. Anyway, intramucosal carcinoma was still considered an invasive neoplasia at that time.

In 2003 Stolte introduced the modified version of the Vienna Classification, combining high grade dysplasia/intra-epithelial neoplasia and intramucosal carcinoma into one category [3]. This up-graded subclassification should have allowed the eventual standardization of the diagnoses between Eastern and Western pathologists for both lesions, which share the same endoscopic treatment. In 2011 the Gastrointestinal Pathology Study Group of Korean Society of Pathologists published the guidelines for the differential diagnosis, defining strict histological criteria [4]. According to them, a diagnosis of carcinoma was based on invasion, a western concept suggested by an important Eastern Pathological Group.

This definition was also included in the last version of the WHO Classification, which was published in 2010 and shared by Western and a few Eastern pathologists [5]. However, some Western pathologists still define high grade dysplasia/intraepithelial neoplasia as tubular adenocarcinoma, irrespective of the invasion of the lamina propria (G.Lauwers and M. Vieth, in press), considering such a lesion at a potential risk of submucosal and/or venous invasion.

So, it seems that we are going on, going back!

In conclusion, although many efforts have been made in order reach an International agreement and standardization, there is still a long way to go because the diagnostic criteria vary widely.

In the meantime, a wide range agreement on the treatment of patients affected by high grade dysplasia and intramucosal carcinoma has been reached, offering a mini-invasive endoscopic approach to the patients in almost cases and by-passing the terminological problem in a certain way.

However, the need, now, is to use a common language.

References

1. Lauwers GY, Shimizu M, Correa P, Riddell RH, Kato Y, Lewin KJ, et al. Evaluation of Gastric Biopsies for Neoplasia: Differences Between Japanese and Western Pathologists. The American Journal of Surgical Pathology. 1999; 23: 511-518
2. Schlemper RJ, Riddell RH, Kato Y, Borchard F, Cooper HS, Dawsey SM, et al. The Vienna classification of gastrointestinal epithelial neoplasia. Gut. 2000; 47: 251-255.
3. Stolte M . The new Vienna classification of epithelial neoplasia of the gastrointestinal tract: advantages and disadvantages. Virchows Arch. 2003; 442: 99-106.
4. Kim JM, Cho MY, Sohn JH, Kang DY, Park CK, Kim WH, et al. Diagnosis of gastric epithelial neoplasia: Dilemma for Korean pathologists. World J Gastroenterol. 2011; 17: 2602-2610.
5. Shin HR, Oh JK, Masuyer E, Curado MP, Bouvard V, Fang Y, et al. Comparison of incidence of intrahepatic and extrahepatic cholangiocarcinoma--focus on East and South-Eastern Asia. Asian Pac J Cancer Prev. 2010; 11: 1159-1166.