14–16 In the most recently-updated cancer staging manual by the American Joint Committee on Cancer and International Union against Cancer, the entire section of gastric cardiac cancer involving the distal esophagus has been removed from the chapter on the stomach into that of the esophagus.17 The manual requires using the esophageal cancer-staging criteria for pathological staging of cancers arising in the proximal stomach with esophageal involvement.17 This dramatic

change in paradigm has prompted us to critically review the histological selleck inhibitor evidence on CG in the proximal stomach published in the recent English literature. In 1961, Salenius published a histological study on gastric mucosal development at different gestational ages.18 The formation of gastric click here pits was found at week 8 in all portions of the stomach, except for the pylorus and cardia. Parietal cells were the first differentiated, glandular

cells, while pyloric glands and CG started to develop at week 13.18 These findings were confirmed by the data from a recent, similar study in 2003.19 Using the PAS–alcian blue stain, the investigators showed the presence of CG in all embryonic specimens.19 In their report, the CG formed a single layer of the epithelium lined with tall columnar cells, with a mucus-filled, apical cytoplasm containing both neutral and sialylated mucins, which differed from parietal cells conspicuously on hematoxylin–eosin (HE)-stained sections. Only neutral mucin was present in most superficial foveolar CG. From gestational age 15 weeks onwards, these mucus cells started to form

the CG that opened into pits. At week 23, the squamous mucosa with remnant ciliated columnar cells replaced the primitive esophageal mucosa, and was positioned proximally to the CG. In the last trimester, Terminal deoxynucleotidyl transferase the CG were further differentiated. At week 41, all CG secreted neutral mucin. The authors emphasized that both the CG and the CM were present in all sections of all cases19 (Table 1). This conclusion was similar to, but differs to some extent from, that of an earlier fetal study in 2001.20 In that report with routine, histological sampling, the CG and oxyntocardiac glands in the transition zone were found in 6% and 52% of cases, respectively.20 Both studies found that the number of CG increased with increasing gestational age.19,20 In 2003, Park et al.21 studied the same transition zone with either HE or PAS staining (Table 1). They found that this transition zone measured <0.4 mm, always contained oxyntic cells, but lacked CG in 20% of cases. This observation is different from that reported by De Hartogh et al.,19 who stated that the “CM was distal to, or straddled, the angle of His in all cases”.