Intestinal metaplasia of the gallbladder: a morphologic and immunocytochemical study

The morphologic spectrum of intestinal metaplasia was studied in 49 gallbladders that had been excised because of cholelithiasis. Based on the absence or presence of endocrine cells, the cases of intestinal metaplasia were arbitrarily divided into two groups. The gallbladders from the first group (26 cases) contained isolated or small clusters of mature goblet cells, while those from the second group (23 cases), in addition to the goblet cells, contained argyrophil and argentaffin cells and, less frequently, Paneth cells and gland-like structures similar to colonic crypts. Pseudopyloric glands and superficial gastric-type epithelium were present in both groups. Argyrophil cells outnumbered argentaffin cells by a ratio of 4 to 1. By immunocytochemical methods serotonin-containing cells were found to be the most common endocrine cells. Other endocrine cells showed immunoreactivity for somatostatin, cholecystokinin, gastrin, and pancreatic polypeptide. The presence of gut endocrine cells and Paneth cells in the pseudopyloric glands suggests that these glands are also an integral component of intestinal metaplasia of the gallbladder. The findings support the hypothesis that cholelithiasis induces the appearance of a stem endodermal cell that, in turn, may differentiate into cells with mature intestinal or gastric phenotypes.     

Paneth Cells in Intestinal Metaplasia of the Stomach and Duodenum of Man

The Paneth cells in intestinal metaplasia of stomach and the duodenum in human subjects were studied ultrastructurally, and the fine structures of these cells were compared. Paneth cells showed the ultrastructure of serozymogenic cells and secreted their secretory granules by merocrine process. The rod or tubular dense bodies were observed in the apical region of some Paneth cells. The structures may have some relation to the secretion of the secretory granules. The secretory granules with less dense layer in the periphery, which had never been described in the Paneth cell of man, were also observed. Morphologically intermediate cells between Paneth cell and goblet cell were found. Some of the Paneth cells might be phagocytized by undifferentiated crypt cells. The Paneth cells in intestinal metaplasia were fundamentally the same as those in duodenum at least in morphology. Difference between them was that Paneth cells with many phagolysosomes in the lower cytoplasm were observed more frequently in the duodenum than in intestinal metaplasia of the stomach. The physiological functions of the Paneth cell have been discussed. ACTA PATH. JAP. 27:677–695, 1977.     

Pancreatic endoproteases and pancreatic secretory trypsin inhibitor immunoreactivity in human Paneth cells.

Normal and metaplastic gastrointestinal mucosa obtained at surgical resection were studied by light microscopy, using the unlabelled antibody enzyme method for immunohistochemical staining of lysozyme, pancreatic endoproteases, and pancreatic secretory trypsin inhibitor (PSTI). Paneth cells in the mucosa of normal small intestine, gastric mucosa with intestinal metaplasia, and colonic metaplastic mucosa were found to contain anionic trypsin, cationic trypsin, lysozyme, and PSTI immunoreactivity, but not chymotrypsin and elastase immunoreactivity. Normal gastric and colonic mucosa and some goblet cells in the small intestine showed positive PSTI immunoreactivity but no endoprotease immunoreactivity. The presence of immunoreactive trypsin and immunoreactive PSTI in the Paneth cells, which are of secretory type, probably indicates an important extrapancreatic source of these proteins rather than a storage of endocytosed material.     

An electron microscopic study of intestinal metaplasia in human gallbladder.

Areas of intestinal metaplastic epithelium in gallbladders removed by cholecystectomies performed for gallstones were studied with the electron microscope. Three gallbladders contained areas of goblet cells and endocrine enterochromaffin-like cells and one gallbladder also Paneth cells. The goblet cells contained mucin granules of slightly variable size and shape and relatively great electron lucency. The intervening columnar epithelial cells contained various amounts of electron-lucent mucin granules. The round or oval enterochromaffin-like cells rested on the basement membrane, and in these cells the small, round, electron-opaque secretory granules were located in the infranuclear region. The supranuclear cytoplasm of the Paneth cells in the intestinalized epithelium contained typical large, round secretory granules. The fine structures of the various cells in the metaplastic epithelium bore resemblance to those of the cells in the intestinalized stomach mucosa.     

Histochemical studies of metaplastic lesions in the human gallbladder

We studied goblet cell metaplasia and pseudopyloric gland metaplasia in 25 surgically removed, paraffin-embedded gallbladder specimens using mucin histochemistry, silver methods for endocrine cells, and the indirect immunoperoxidase method for 12 peptide hormones, secretory component, and lysozyme. Goblet cell metaplasia was closely related to the occurrence of endocrine cells that showed argentaffinity, argyrophilia, or immunoreactive gastrin, somatostatin, pancreatic polypeptide, or motilin. Mucosal areas without goblet cell metaplasia were devoid of such endocrine cells. Metaplastic pseudopyloric glands showing lysozyme immunoreactivity were positive for class III mucin with paradoxical concanavalin A staining. Specimens with florid metaplastic lesions revealed a low tendency to form Rokitansky-Aschoff sinuses whose cells never showed a metaplastic nature. We compared the pathophysiological significance of metaplastic lesions in the gallbladder with intestinal metaplasia of the stomach.     

Expression of calnexin reflects paneth cell differentiation and function

It has been suggested that the behavior and function of Paneth cells in metaplasia are different from those found in normal intestinal mucosa. In this study, we investigated whether calnexin, a protein involved in secretory pathways, might be associated with differentiation and function of Paneth cells in normal small intestine, in complete intestinal metaplasia of the stomach, and in Paneth cell-rich adenomas. Differentiation and function of Paneth cells was monitored by Ki67, lysozyme, and morphologic features. Using a newly established monoclonal antibody, we found that calnexin is regularly synthesized by Paneth cells of normal small intestine. In these cells, the staining intensity of calnexin was inversely correlated with their content of secretory granules (lysozyme). In contrast, Paneth cells of intestinal metaplasia and Paneth cell-rich adenomas showed a reduced immunostaining of both calnexin and lysozyme. Moreover, these Paneth cells synthesized the proliferation marker Ki67, a phenomenon that was never observed in Paneth cells of normal small intestine. In vitro experiments using CaCo2 cells showed that the expression of calnexin is not directly affected by the induction of mitosis. In conclusion, calnexin probably reflects the status of Paneth cell differentiation and function. The results do not necessarily indicate that calnexin has a function in Paneth cell proliferation.     

Identification of Paneth cells in pyloric glands associated with gastric and intestinal mixed-type intestinal metaplasia of the human stomach

We have proposed that intestinal metaplasia (IM) of the human stomach be divided into two types on the basis of cell differentiation status: a gastric and intestinal (GI) mixed type and a solely intestinal (I) type. In the GI mixed type, gastric (foveolar epithelial and pyloric gland cells) and intestinal (goblet, intestinal absorptive, and Paneth cells) phenotype cells coexist in the same intestinalized gastric glands in various combinations and degrees. Consequently, intestinalized gastric glands are hybrids. Although we have described the rare appearance of Paneth-like cells in pyloric glands of GI mixed-type IM, the absence of an appropriate Paneth cell marker leaves room for doubt as to their true character. The purpose of this study was to clearly identify Paneth cells in pyloric glands in IM lesions using a new Paneth cell marker, a polyclonal antibody human defensin (HD)-5, raised against HD-5, which is included in granules of Paneth cells. A total of 105 gastric samples (4 biopsy and 101 surgical resected specimens) were examined. In only nine cases (8.6%), the antibody allowed demonstration of Paneth cells in pyloric glands in GI mixed-type IM, confirming our previous finding. Analysis of the proliferative cell (P) zone indicated that a common stem cell might generate both GI phenotype cells by upward and downward migration. No Paneth cells were found above the P zone. The results suggest that the stem cells show abnormal cell differentiation in IM lesions but preserve their normal direction of migration.     

Loss of differentiation in intestinal metaplasia in cancerous stomachs. A comparative morphologic study.

229 stomachs resected for duodenal and gastric ulcer and carcinoma were examined with special regard to the morphological and histochemical pattern of intestinal metaplasia (IM). The results of qualitative and semiquantitative studies were analysed statistically. Whereas duodenal and gastric ulcer cases are best discriminated by the presence or absence of IM, the strongest discriminating factor between carcinoma and gastric ulcer is the content of goblet cells in metaplastic crypts. Metaplastic crypts lined exclusively with goblet cells producing sulfated acid glycoproteins could be identified in more than one third of the cancer cases. The increase in goblet cells coincides with a loss of the more differentiated cells in the metaplastic glands, such as enterocytes, APUD cells, or Paneth cells. This "enterocoli metaplasia" seems to be specific for cancer bearing mucosa and occurs more often in cancer of intestinal type; it may represent a form of a derepressive dedifferentiation. The significance of enterocoli metaplasia as a premalignant lesion remains to be elucidated.     

Histochemical similarities of mucins produced by Brunner's glands and pyloric glands: A comparative study

Mucins of the gastroduodenal junction are secreted by the mucous surface and mucus-producing glandular cells in the stomach, and by goblet cells and Brunner's glands in the duodenum. Developmental studies have demonstrated that Brunner's glands can arise from undifferentiated gastric epithelium and/or intestinal epithelium in the proximal duodenum. The aim of this study was to investigate the carbohydrate composition of mucins from this region and compare it with that of mucins from Brunner's glands to evaluate the probable evolution of mucins from these glands. Toward that end, paraffin sections from 13 mammalian species were stained by classic carbohydrate histochemistry and treated with 13 lectins. In general, the mucous surface cells of the stomach, pyloric glands, duodenal goblet cells, and Brunner's glands secretory epithelium had different lectin-binding patterns. However, the lectin-binding profile of the secretory epithelium of Brunner's glands resembled that of pyloric glands more closely than that of duodenal goblet cells and mucous surface cells of the stomach. Mucins from Brunner's glands and pyloric glands showed a greater terminal carbohydrate residue diversity than those of gastric mucous surface cells or duodenal goblet cells. The lectin-binding profile argues for the evolution of similar mucins from the epithelia of Brunner's glands and pyloric glands. The greater diversity of carbohydrate residues in mucins secreted by Brunner's glands suggests that their mucus is more adaptable. This may explain why Brunner's glands metaplasia rather than goblet cell metaplasia is seen in the mucosa adjacent to chronic intestinal ulcers.     

Entero-endocrine cell differentiation in carcinomas of the gallbladder and mucinous cystadenocarcinomas of the pancreas

Forty two carcinomas of the gallbladder and 25 mucinous cystadenocarcinomas of the pancreas were analyzed using silver stains and immunohistochemical techniques. Fourteen (33.3%) gallbladder carcinomas had argyrophil and argentaffin cells and 17 (40%) contained endocrine cells as shown by immunoperoxidase stains. The gallbladder tumors that had the largest number of endocrine cells were the well differentiated adenocarcinomas with colonic features. The most common endocrine cell in these tumors was the serotonin-containing (EC) cell followed by somatostatin-containing cells and cells that reacted to pancreatic polypeptide and gastrin. Intestinal metaplasia with pseudopyloric gland hyperplasia was present in the gallbladder mucosa adjacent to 11 carcinomas and had an endocrine cell population similar to that of the tumors. Endocrine cells were demonstrated in 18 (70%) of the 25 mucinous cystadenocarcinomas of the pancreas by the immunoperoxidase method although only 9 had argyrophil and argentaffin cells. The population of endocrine cells in these mucinous pancreatic tumors was similar to that found in gallbladder carcinomas. Endocrine cells were more numerous in areas with colonic-type glands, goblet cells and Paneth cells. The secretory products of the endocrine cells in these gallbladder and pancreatic tumors did not give rise to systemic endocrine manifestations. The presence of endocrine cells in these tumors can be explained on the basis of intestinal differentiation.     

Functional activity of intestinal epithelium demonstrated by mRNA in situ hybridization

To elucidate the synthetic activity in relation to the morphology of the epithelial cells of the small and large intestine, in situ hybridization with a poly-deoxyribothymidine (poly d(T)) probe was applied to paraffin sections of formalin-fixed blocks. This effectively displays poly-adenylated RNA and, by implication, messenger RNA (mRNA). By minimizing proteinase K pretreatment, the relative concentrations of cellular mRNA were visualized. This revealed minimal mRNA in crypt columnar cells, and maximal mRNA in proliferating cells and in cells showing terminal differentiation. The latter include surface epithelial cells, endocrine cells, Paneth cells, and maturing, but not mature, goblet cells. The goblet cells showing positive hybridization can be regarded as active cells and show characteristic morphology. Such cells are particularly evident in untreated coeliac disease, remitting ulcerative colitis, and transitional mucosa. The proliferating cells showing increased hybridization include normal mitotically active crypt epithelium, regenerating epithelium in ulcerative colitis, adenomatous epithelium, and adenocarcinomatous epithelium. The similarity of hybridization between metaplastic polyp epithelium and surface colonocytes is consistent with the concept that metaplastic polyps are formed of cells showing premature terminal differentiation.     

Emc3 maintains intestinal homeostasis by preserving secretory lineages

Intestinal exocrine secretory lineages, including goblet cells and Paneth cells, provide vital innate host defense to pathogens. However, how these cells are specified and maintained to ensure intestinal barrier function remains poorly defined. Here we show that endoplasmic reticulum membrane protein complex subunit 3 (Emc3) is essential for differentiation and function of exocrine secretory lineages. Deletion of Emc3 in intestinal epithelium decreases mucus production by goblet cells and Paneth cell population, along with gut microbial dysbiosis, which result in spontaneous inflammation and increased susceptibility to DSS-induced colitis. Moreover, Emc3 deletion impairs stem cell niche function of Paneth cells, thus resulting in intestinal organoid culture failure. Mechanistically, Emc3 deficiency leads to increased endoplasmic reticulum (ER) stress. Mitigating ER stress with tauroursodeoxycholate acid alleviates secretory dysfunction and restores organoid formation. Our study identifies a dominant role of Emc3 in maintaining intestinal mucosal homeostasis.     

Varying occurrence of gastroduodenal immunoreactive pancreatic secretory trypsin inhibitor.

Operative specimens from various parts of gastroduodenal mucosa were analysed for immunoreactive pancreatic secretory trypsin inhibitor (PSTI) using a peroxidase-antiperoxidase method. Normal gastric mucosa exhibited a varying degree of PSTI immunoreactivity, which was more pronounced in the foveolar cells of gastric mucosa of fundus type than in the non-pepsinogen producing antrum-pyloric mucosa. With the exception of metaplastic Paneth cells and some goblet cells, the intracellular content of PSTI was low in gastric mucosa with intestinal metaplasia. These findings may indicate that a PSTI immunoreactive substance has a role in the normal defence of the gastric mucosa.     

Morphological range of hyperplastic polyps and carcinomas arising in hyperplastic polyps of the stomach.

A morphological range of 67 hyperplastic polyps was studied. They included polyps removed endoscopically and polyps found incidentally in resected stomachs with gastric ulcers and cancer. The hyperplastic polyps were essentially composed of cystic foveolae and pyloric type glands, lined by cells identical to those of the normal gastric mucosa. Thirty one polyps contained other cytological elements. In 18, intestinal metaplasia was seen; the tubules were mostly composed of columnar and goblet cells and lacked Paneth cells. In 11 polyps, nine cases of gastric dysplasia and two cases of intestinal dysplasia, dysplastic changes were found. The former consisted of a proliferation of irregularly shaped pits with pleomorphic cuboidal/columnar cells with relatively basophilic cytoplasm. They contained mucigen granules of a gastric type. The latter consisted of atypical pits composed of closely packed, tall columnar and small goblet cells, both resembling adenomatous cells of the colon. In three polyps carcinomas were seen, one of which was an intestinal type adenocarcinoma. In the other two, the cancer cells closely resembled the normal foveolar cells, containing gastric type mucigen granules. They were gastric type adenocarcinomas.     

Are metaplasias in colorectal adenomas truly metaplasias?

Five thousand seven hundred seventy-eight adenomas or adenomas containing carcinoma from 3215 patients were examined by routine histologic methods for the presence of epithelial metaplasias. Three forms of epithelial metaplasia were encountered: squamous cell metaplasia (0.44%), Paneth cell metaplasia (0.20%), and melanocytic metaplasia (0.017%). In several instances multiple forms of metaplasia were encountered in the same polyp. In those cases in which the paraffin blocks were available, a Grimelius stain was performed. Grimelius-positive cells were present in 63% of the adenomas containing a metaplastic cell type. All cases with Paneth cell differentiation were immunoreactive for lysozyme; all lesions containing areas of squamous differentiation were immunoreactive for keratin except 2. The histopathologic features of these cases are discussed, and it is concluded that rather than representing a true metaplastic process, Paneth cell, squamous cell, and melanocyte differentiation represent the full range of cellular differentiation that endodermally derived tissues can exhibit, particularly when they undergo neoplastic alterations.     

Small cell carcinoma of the gall-bladder with intestinal metaplastic epithelium

A case of small cell carcinoma of the gall-bladder Is described. lmmunohistochemically, the tumor cells were positive for chromogranin A, synaptophysin and neuronspecific enolase, which suggests that they derived from neuroendocrine cells. The overlying and surroundlng epithelium of the tumor showed intestinal metaplasia including goblet cells, pseudopyloric glands, Paneth's cells, and chromogranin A and synaptophysin-positive endocrine cells. Definite adenocarcinoma was absent. The endocrine cells in the epithellum were more numerous In the vicinity of the tumor. The present case supports the supposition that endocrine cell tumor (including small cell carcinoma) of the gall-bladder may develop from endocrine cells of the intestinal metaplastic lesion.     

Immunohistochemical study of enterochromaffin-like cell in human gastric mucosa

Enterochromaffin-like (ECL) cell has been identified as the histamine-containing argyrophil cell in rat gastric mucosa and vigorously studied. However, there are few reports of the distribution of ECL cell in human stomach. The aim of the present study was to determine the precise distribution of ECL cell by immunohistochemical staining of histidine decarboxylase (HDC) and gastrin-cholecystokinin B receptor (CCK-BR) in human stomach, and the correlation between their distribution and that of parietal cells. Thirty specimens of surgically resected stomach were used. Parietal cell, Grimelius-silver-positive cell, gastrin, HDC- and CCK-BR-immunoreactive cell were studied on continuous cell counting in the restricted field along the lamina muscularis from the oral to the anal ends. The percentage of HDC-immunoreactive cells of endocrine cells was smaller (15%) than that of a previous report (35%) in the fundic region. HDC- and CCK-BR-immunoreactive cells were found not only in the fundic region, but also in the intermediate and pyloric regions. In the pyloric region, HDC- and CCK-BR-immunoreactive cells were found mainly in the mucosa with intestinal metaplasia. Double-positive cells were also found, but only in small numbers. This suggests that ECL cell, or a cell sharing its function, is present in the pyloric region.     

Modifications of gastric mucosa in diffuse and intestinal cancer

The study was made of 29 intestinal type gastric carcinomas, 37 diffuse type gastric carcinomas and stomach mucosa (SM). Both carcinomas slightly differed by frequency of the fundal glands atrophy. Intestinal type was characterized by a higher frequency of antral glands atrophy, intestinal metaplasia, particularly of colon type. Intestinal cell differentiation was about the same in both types. Hyperplasia of lining and endocrine cells in the fundal part of the mucosa was more frequent and neuroendocrine differentiation was more pronounced in diffuse stomach carcinoma. It is suggested that environmental impacts including helicobacter pylori result in proliferation of the epithelium, intestinal metaplasia, dysplasia and carcinoma of the intestinal type. Diffuse carcinoma is associated with proliferation of glandular epithelium (parietal, endocrine, cervical) due to genetic factors, hypergastrinemia caused by fundal gland atrophy, alkalization of the mucosa due to Helicobacter pylori infection.