Histopathological study of mucosal and submucosal cysts of stomach

To clarify the characteristics of mucosal and submucosal gastric cysts, five stomal cancers of the remnant stomach, two cancers with a diffuse cystic distribution and three ordinarily resected cancers were used to study mucinous patterns, proliferative cells and humoral defensive factors in the cystic epithelia. Most cysts showed a gastric appearance with relatively dominant ConA III (+) pyloric gland-like features, and were positively stained with high-iron diamine-alcian blue. Although a few cells positive for proliferative cell nuclear antigen (PCNA) were seen in epithelia, cysts generally revealed a low degree of proliferation, less than 2% of epithelial cells being PCNA (+). Cysts were formed from the isthmus or from ordinary glands, and showed an increase of IgA and secretory component in epithelia of the supranuclear, luminal or basolateral region and increased lysozyme (Ly) activity. Some cysts contained cells with strong positivity for Ly which could not be confirmed as Paneth cells by HE staining. Mucosal and submucosal cysts are considered to arise as a reaction to inflammation, and have a tendency to show both gastric and intestinal characteristics.