A renewed insight into Barrett's esophagus: comparative histopathological analysis of esophageal columnar metaplasia

Specialized intestinal metaplasia (SIM) is considered as a premalignant condition of the esophagus, but other types of esophageal metaplasia are commonly neglected. A standardized histopathological analysis was focused not only on SIM but also on the presence of metaplastic processes typical of additional glands. A morphological study using standardized histopathological tests was carried out between 2004 and 2007, with biopsies taken from esophageal mucosa of 826 consecutive patients. Mean age and male : female ratio of patients were 55.6 ± 14.7 and 1.1 : 1, respectively. Only 4.1% (n = 34) of all cases proved to have SIM. The remainder of the cases (n = 615; 74.4%) contained cardiac-fundic mucosa without SIM. Some samples exhibited superficial mucous glands, pancreatic acinar metaplasia (PAM), and ciliated metaplasia accounting for 24% (n = 198), 14.9% (n = 123), and 0.2% (n = 2), respectively. SIM was colocalized with superficial mucous glands (103/198 superficial mucous gland cases; P < 0.001). Low-grade dysplasia (n = 51; 6.2%) and high-grade dysplasia (n = 9; 1.1%) were found mainly in SIM (37/51; 9/9; P = 0.071) with male preponderance (3 : 1 at low-grade and 2 : 1 at high-grade dysplasia). PAM was found mainly in cases without dysplasia (103 of 123 pancreatic metaplasias; P < 0.001). SIM alone in the esophagus is rare, and its frequent association with cardiac mucosa-type metaplasia testifies to transition of mucinous-goblet cell through pseudogoblet cells. PAM rather indicates absence of dysplasia, but superficial mucous glands predicts that SIM follows dysplasia.