A “rose is a rose is a rose is a rose,” but exactly what is a gastric adenocarcinoma?

In the 14 July 1997, issue of Lancet, Schlemper et al. [1] reported a study in which four Japanese and four Western pathologists (from the United States, Canada, Germany, and Finland) compared their diagnoses of gastric biopsy and resection specimens having epithelial lesions ranging from reactive, through preneoplastic, to invasive carcinoma. These pathologists independently classified microscopic slides from 17 biopsies and 18 mucosal resections of 19 cases of neoplastic and nonneoplastic gastric epithelium. All of the lesions were superficial, involving only the mucosa, or when invasive, not extending beyond the submucosa, thus including examples of early gastric cancer. The selection of primarily superficial lesions focused attention on the minimal criteria required for the diagnosis of malignancy by pathologists from different parts of the world. The pattern that emerged indicated that the terminology favored by the Japanese pathologists differed from that favored by three of the Western pathologists for the same lesions; the fourth Western pathologist sided with the Japanese. Specifically, the Japanese pathologists’ threshold for diagnosing carcinoma was lower than that of the Western pathologists. The Japanese did not require the presence of invasion for a diagnosis of adenocarcinoma of the