Gastrointestinal polyposis

The Frontiers of Serrated Polyps

The serrated pathway of carcinogenesis has been the subject of intense investigation over the past 2 decades, but many gaps in our understanding still need to be resolved. Serrated polyp precursors include hyperplastic polyps, sessile serrated polyps, and traditional serrated adenomas. These are considered discrete entities, but there is emerging molecular data to suggest that they may be more closely related to each other than currently believed. The recent US Multi-Society Task Force surveillance guidelines for patients with serrated polyps are admittedly based on low quality evidence. In this brief review, we discuss the limitations in endoscopic detection and pathologic interpretation of serrated polyps and the implications of these diagnostic difficulties on risk prediction and postpolypectomy surveillance recommendations.

Serrated Polyps and Serrated Polyposis Syndrome

Colorectal serrated polyps are intermediate lesions in the serrated neoplastic pathway, which account for up to 30% of colorectal cancers. This pathway is biologically distinct from the adenoma-to-carcinoma sequence, with associated cancers exhibiting mutations in the BRAF oncogene, DNA promoter hypermethylation, and microsatellite instability. An evolving understanding of these unique lesions has led to the development of a more accurate classification, improved endoscopic identification, and tailored clinical management guidelines. This article reviews serrated polyps and serrated polyposis syndrome.

Serrated polyps and their alternative pathway to the colorectal cancer: a systematic review

Colorectal cancer (CRC) is the third most frequently diagnosed cancer in the world. For a long time, only one pathway of colorectal carcinogenesis was known. In recent years, a new “alternative” pathway through serrated adenoma was described. Recent meta-analysis estimated these cancers as about 10% to 30% of all CRCs. Serrated polyps are the second most popular groups of polyps (after conventional adenomas) found during colonoscopy. Serrated polyps of the colon are clinically and molecularly diverse changes that have common feature as crypt luminal morphology characterized by glandular serration. Evidence suggests that subtypes of serrated polyps, particularly TSA and SSA/P, can lead to adenocarcinoma through the serrated pathway. Moreover, the data indicate that the SSA/P are the precursors of colorectal carcinoma by MSI and may be subject to rapid progression to malignancy. An important step to reduce the incidence of CRC initiated by the serrated pathway is to improve the detection of serrated polyps and to ensure their complete removal during endoscopy. Understanding of the so-called serrated carcinogenesis pathway is an important step forward in expanding possibilities in the prevention of CRC.

Phenotype and polyp landscape in serrated polyposis syndrome: a series of 100 patients from genetics clinics

Serrated polyposis syndrome (SPS), also known as hyperplastic polyposis, is a syndrome of unknown genetic basis defined by the occurrence of multiple serrated polyps in the large intestine and associated with an increased risk of colorectal cancer (CRC). There are a variety of SPS presentations, which may encompass a continuum of phenotypes modified by environmental and genetic factors. To explore the phenotype of SPS, we recorded the histologic and molecular characteristics of multiple colorectal polyps in patients with SPS recruited between 2000 and 2010 from genetics clinics in Australia, New Zealand, Canada, and the United States. Three specialist gastrointestinal pathologists reviewed the polyps, which they classified into conventional adenomas or serrated polyps, with various subtypes, according to the current World Health Organization criteria. Mutations in BRAF and KRAS and mismatch repair protein expression were determined in a subset of polyps. A total of 100 patients were selected for the study, of whom 58 were female and 42 were male. The total polyp count per patient ranged from 6 to 150 (median 30). The vast majority of patients (89%) had polyposis affecting the entire large intestine. From this cohort, 406 polyps were reviewed. Most of the polyps (83%) were serrated polyps: microvesicular hyperplastic polyps (HP) (n=156), goblet cell HP (n=25), sessile serrated adenoma/polyps (SSA/P) (n=110), SSA/P with cytologic dysplasia (n=28), and traditional serrated adenomas (n=18). A further 69 polyps were conventional adenomas. BRAF mutation was mainly detected in SSA/P with dysplasia (95%), SSA/P (85%), microvesicular HP (76%), and traditional serrated adenoma (54%), whereas KRAS mutation was present mainly in goblet cell HP (50%) and in tubulovillous adenoma (45%). Four of 6 SSA/Ps with high-grade dysplasia showed loss of MLH1/PMS2 expression. CRC was diagnosed in 39 patients who were more often found to have a conventional adenoma compared with patients without CRC (P=0.003). Patients with SPS referred to genetics clinics had a pancolonic disease with a high polyp burden and a high rate of BRAF mutation. The occurrence of CRC was associated with the presence of conventional adenoma.

[Regional growth preferences in hereditary, synchronous, and metachronous colorectal carcinomas. Basics of tumor surgery Part II]

This article discusses the therapeutic importance of the loss of self-regulation of cell division in polypoid adenomas and in the cloacogenic, cancerophilic rectal segment. Regional growth preferences can observed in familial adenomatous polyposis (FAP) and ulcerative colitis, as in other diseases featuring a cancerous disposition on the mucosa. For example, rectal carcinomas are more common than colon carcinomas if one considers the total mucosal surface area at risk. Malignant changes do not occur randomly in existing adenomas of FAP patients, and the adenomas' cell division--as in other adenomas--is governed by some degree of self-regulation. In FAP patients undergoing proctocolectomy, preferred new growth areas for carcinomas include the duodenum and ileum. In patients with synchronous colorectal cancers, the rectum is more commonly affected than other colon segments. If the rectum is resected, metachronous carcinomas are exceedingly rare in the remaining colon segments. Clinical decisions about rectal resection must be informed by understanding of the importance of this organ for anorectal continence as well as the described growth of colorectal malignancies.

Misplacement of dysplastic epithelium in Peutz-Jeghers Polyps: the ultimate diagnostic pitfall?

Peutz-Jeghers syndrome is characterized by multiple polyps throughout the gastrointestinal tract in association with mucocutaneous pigmentation. Small bowel polyps in the syndrome may exhibit epithelial misplacement, into the submucosa, the muscularis propria, and even the subserosa. The authors demonstrate two patients in whom there is also misplacement of dysplastic epithelium into the submucosa and muscularis propria of the small bowel. Epithelial misplacement is recognized to mimic invasive malignancy. Such mimicry is heightened substantially when the misplaced epithelium is dysplastic. Correct interpretation of the histologic changes is aided by the use of special stains, which demonstrate the associated lamina propria and the lack of a desmoplastic response, and immunohistochemistry, which shows that the misplaced dysplastic epithelium is accompanied by non-neoplastic mucosa. There is an increased prevalence of gastrointestinal malignancy in Peutz-Jeghers syndrome. However, the presence of perplexing histologic features, caused by epithelial misplacement, especially when some of that epithelium is dysplastic, in small bowel polyps at least has the potential for the overdiagnosis of malignancy in the syndrome.

Hamartomatous polyps in the intestine of two dogs

Partly obstructing, proliferative mucosal masses in the small intestine of two dogs were shown histologically to be hamartomatous polyps. They were characterized by an extension of smooth muscle from the muscularis mucosae into the lamina propria of the lesion. This is the first report of such lesions in domestic animals. In one of the dogs the lesion had become malignant.

A case report of juvenile polyposis with adenomatous change and a review of 34 cases reported in Japan

It has recently come to be thought that cases of juvenile polyposis have a natural tendency to develop adenoma and/or carcinoma. Here we present a case of juvenile polyposis coli with adenomatous change in a 21-year-old male, with a review of 34 cases of juvenile polyposis in the Japanese literature, and discuss the pathogenetic development of the polyps and their malignant potential. In this case, focal or entire adenomatous areas were found in large part of the polyps in the resected sigmoid colon and rectum, though these findings had not been recognized in 23 polypectomy specimens from the rectum 10 months prior to the operation. It was suggested that adenomatous change developed quickly in a very short time.

Benign lymphoid polyposis of the colon. Report of a case in an adult

A new case of benign lymphoid polyposis of the colon in an adult is presented. Relatively frequent in childhood, this disease remains exceptional in adults. The main concern is differentiation from adenomatous polyposis; the differential diagnosis can be particularly difficult for complex forms of polyposis with coexistent adenomatous and lymphoid polyps. Benign lymphoid polyposis of the colon does not appear to have any propensity for malignant degeneration, and major surgical resection is not indicated.

Investigations on the significance of the adenoma-carcinoma sequence in the small bowel

In view of the rarity of small-bowel epithelial neoplasms as compared with the case for the large bowel, evidence for an adenoma-carcinoma sequence in the small bowel was studied based on a search for data in the medical literature for the years 1927 through 1986. Sufficiently defined data were found for comparison of 185 benign adenomas, 76 adenoma-with-carcinomas, and 1333 carcinomas in patients without familial polyposis disease and for 63, five, and 30, respectively, in patients with disease. For patients without polyposis, it was found that (1) 29.8% of all small-bowel adenomas (33.6% if those at Vater's ampulla are excluded) showed malignancy; (2) the mean and median ages were lower for benign adenoma than for adenoma-with-carcinoma and carcinoma, although the ratios by sex were the same; (3) there is a nearly identical spatial distribution of the three types of epithelial neoplasms within the small bowel; and (4) both the frequency of finding adenomatous residues existing in continuity with carcinoma and the life history of the adenoma-carcinoma sequence are similar in the small bowel as in the large. In comparing these results with those from patients with familial polyposis disease, it was particularly noted that (1) the only difference was that adenomas in familial polyposis occurred earlier and multiply, and (2) the spatial distributions of adenomas and carcinomas for both cases were closely similar. It is therefore postulated that the adenoma-carcinoma sequence is as significant in the small bowels as in the large. A hypothesis regarding the relationship of epithelial neoplasms in people with and without familial polyposis disease is suggested.

Epithelial polyps of the large intestine. A classification based on biologic behavior

Classifications of colonic polypoid lesions are often based on their pathogenesis. Little attention is paid to the biologic behavior (or predicted behavior, based on experience) of these lesions. Classification based on biologic behavior separates these lesions, regardless of histogenesis, according to possible malignant potential. This helps the clinician to explain the implications of the histopathologic diagnosis to the patient and to understand when aggressive or prophylactic therapy should be pursued.

Colorectal juvenile polyps: an epidemiological and histopathological study of 144 cases in Jordanians

The minimal incidence rate of colorectal juvenile polyps in Jordanians was 1.4 per 100 000 in the general population and 2.8 per 100 000 in children under 10 years of age. Out of 144 cases, nine had two to seven polyps and one juvenile polyposis coli. There was male preponderance and a mean age of 8 years: 96.5% of the polyps were in the rectum. Characteristically, stromal oedema, inflammation, ulceration with granulation tissue cap formation and gland regeneration were present. Epithelial hyperplasia was not uncommon and focal dysplastic change was occasionally noted, being always accompanied by hyperplastic change. Focal severe dysplasia was seen in one solitary juvenile polyp. It is concluded that varying degrees of focal epithelial atypia can occasionally develop in solitary juvenile polyps, rarely reaching severe dysplastic change. Malignant transformation in the commonly seen form of juvenile polyp (solitary type) is probably a rare phenomenon, but its frequency needs further evaluation.

Juvenile polyposis of the colon with atypical adenomatous changes and carcinoma in situ. Report of a case and review of the literature

Juvenile polyps are thought to have no malignant potential; however, we report a case of diffuse juvenile polyposis coli in a 19-year-old man where mucosal dysplastic changes ranging from mild dysplasia to carcinoma in situ are present. The pathogenetic development of these polyps and their malignant potential are discussed.

Adenomatous and carcinomatous changes in hamartomatous polyps of the small intestine (Peutz-Jeghers syndrome): report of a case and review of the literature

The authors report the unique case of a patient with the Peutz-Jeghers (P-J) syndrome who had multiple small bowel hamartomatous polyps, some of which also showed adenomatous and carcinomatous changes. Over the course of 30 years, over 100 small bowel and colonic polyps were resected; all histologically demonstrated the typical features seen in hamartomatous polyps. Several jejunoileal polyps excised during the last few months of the patient's life showed not only hamartomatous features but also adenomatous epithelium. As far as the authors can determine, this is the first documented case of adenomatous changes found within a small bowel hamartomatous polyp. In addition, at least one duodenal polyp demonstrated areas of hamartoma, adenoma, and in situ carcinoma. The literature on the occurrence of gastrointestinal adenomas and carcinomas in patients with the P-J syndrome is reviewed, and the relationship of hamartomas, adenomas, and carcinomas of the gastrointestinal tract is discussed.

Adenomatous and carcinomatous changes in hamartomatous polyps of the small intestine (Peutz-Jeghers syndrome): report of a case and review of the literature

The authors report the unique case of a patient with the Peutz-Jeghers (P-J) syndrome who had multiple small bowel hamartomatous polyps, some of which also showed adenomatous and carcinomatous changes. Over the course of 30 years, over 100 small bowel and colonic polyps were resected; all histologically demonstrated the typical features seen in hamartomatous polyps. Several jejunoileal polyps excised during the last few months of the patient's life showed not only hamartomatous features but also adenomatous epithelium. As far as the authors can determine, this is the first documented case of adenomatous changes found within a small bowel hamartomatous polyp. In addition, at least one duodenal polyp demonstrated areas of hamartoma, adenoma, and in situ carcinoma. The literature on the occurrence of gastrointestinal adenomas and carcinomas in patients with the P-J syndrome is reviewed, and the relationship of hamartomas, adenomas, and carcinomas of the gastrointestinal tract is discussed.

Atypical juvenile polyposis

Two cases of atypical juvenile polyposis are described in males of 9 months and 25 years-of-age. The first was associated with congenital megacolon and presented as juvenile polyps with features suggesting mild dysplasia. In the second case six histological lesions are found: I hyperplastic polyps; 2 juvenile polyps; 3 hyperplastic polyps with adenomatous areas; 4 juvenile polyps with areas of dysplastic epithelium; 5 adenomas; and 6 adenocarcinomas. On the basis of the morphological features we propose a pathogenetic sequence of focal mucosal hyperplasia to adenoma and carcinoma through stages of non-neoplastic and non premalignant polyps. Finally, the possibility that hyperplastic epithelium can in some circumstances have a greater dysplastic potential that normal colorectal mucosa is raised.

Gardner's syndrome. Recent developments in research and management

In recent years, a number of comprehensive reviews have been written on inherited intestinal polyposis syndromes (1-7), but none has dealt specifically with Gardner's syndrome and none has focused on basic research being carried out in an attempt to understand this syndrome and to improve the medical management of affected patients. A better understanding of this rare genetic disorder is essential for surgeons, gastroenterologists, cancer researchers, and geneticists alike. To the clinician, it poses difficult challenges in management; to the cancer researcher, it presents a rare opportunity to study very early premalignant transformations; and to the geneticist, it poses exciting questions at the cellular, chromosomal, and molecular levels.

Gastric hamartomatous polyps in the absence of familial polyposis coli

Hamartomatous polyps in the stomach have been described as gastric lesions of familial polyposis coli. Four cases of multiple gastric hamartomatous polyps not associated with polyposis coli were encountered. Histologically, all these polyps consisted of normal oxyntic glands with numerous cystic dilatations of the glandular lumens of various sizes. Endoscopically, the polyps were all located in the acid secreting area and had an acid secreting function, which was revealed by the endoscopic Congo red test.

Gardner syndrome and periampullary malignancy

In a family with colonic polyposis and the typical associated findings of Gardner syndrome (osteomas and soft-tissue tumors), two and possibly four of the affected members developed periampullary malignancy. A review indicates that individuals with Gardner syndrome may have a 100- to 200-fold increased risk of developing periampullary carcinoma when compared to the general population. While certain families and certain individuals (those with other duodenal involvement, males and those with all of the characteristics of Gardner syndrome expressed) may be most susceptible, all patients with Gardner syndrome should be periodically endoscopically evaluated for the presence of upper gastrointestinal tract disease.

Peutz-Jeghers syndrome associated with gastrointestinal carcinoma. Report of two cases in a family

Patients with the Peutz-Jeghers syndrome carry a slight, though definite, increased risk of gastrointestinal carcinoma. The malignant potentiality of Peutz-Jeghers hamartomatous polyps, generally considered benign, is supported by this report. Two cases of metastasising gastrointestinal carcinoma associated with the Peutz-Jeghers syndrome are described in a 56 year old female and her 29 year old son. Both mother and son died from duodenal and gastric carcinomas respectively, which developed in hamartomatous polyps with extensive metastases. Both cases also showed dysplastic areas within hamartomatous polyps. These features indicate that hamartomatous polyps may, in some cases, be the precursors of digestive tract carcinomas.

Peutz--Jeghers syndrome with pseudoinvasion of hamartomatous polyps and multiple epithelial neoplasms

The risk of malignant change developing in the hamartomatous polyps in Peutz-Jeghers syndrome is widely held to be negligible. However an association with tumours of the upper gastro-intestinal tract, ovary and other diverse multiple neoplasms is now recognized. Previously reported cases of malignant change in Peutz--Jeghers polyps may represent 'pseudoinvasion' and we report such a case. This was associated with carcinomas of the bile ducts, left tonsil and a papillary adenoma of the pancreatic duct. It lends further support to the view that there may be a genetic predisposition to the development of neoplasms in this condition. Pathologists and clinicians must be aware of this entity of 'pseudoinvasion' in order to avoid unnecessarily radical surgery in Peutz-Jeghers syndrome.

Juvenile colonic polyposis associated with congenital heart disease

Four members of a family with juvenile colonic polyposis in two generations were examined by the authors. The disease showed a very marked dominant mode of inheritance, not sex-linked, in this family. At the same time, the same members of the family had congenital heart disease, including atrial septal defects and pulmonary stenosis. This disease also resulted from a dominant, highly penetrating gene, not sex-linked. The occurrence of both these hereditary diseases at the same time suggests a close relationship or link between the responsible genes. This combination may represent the emergence of a new syndrome.

Cronkhite-Canada syndrome. Case report

The case report of a 72-year-old man with the characteristic clinical and pathologic-anatomic picture of the Cronkhite-Canada syndrome is presented. The clinical features and the radiographic appearance of the gastrointestinal tract suggested Ménétrier's disease. Subtotal gastrectomy was performed and at the subsequent pathologic-anatomic examination, the diagnosis of Cronkhite-Canada syndrome was made. The patient slowly recovered over the following five months while being treated with the so-called astronaut diet (Vivasorb) supplemented with vitamins, iron and electrolytes. He died five months after surgery from intercurrent disease. The differential diagnosis of gastrointestinal polyposis with or without mucocutaneous pigmentation is briefly discussed. The histochemical characteristics of the epithelium in the gastric and colonic polyps was studied in some detail. The authors believe that the gastrointestinal polyps in the Cronkhite-Canada syndrome are regenerative and non-neoplastic in nature.

II. Malignant potential of gastric polyps

The malignant potential of gastric polyps is correlated to their features. The vast majority can be divided into two types: hyperplastic polyp and ademona. Hyperplastic polyp is composed of well-differentiated glands and rarely becomes malignant. It is small, smooth-surfaced, often multiple, and randomly distributed. Adenoma is composed of dysplastic glands and often becomes malignant. The small adenoma is flat-surfaced and slightly raised. The large adenoma is papillary and broad-based. Adenoma is usually single and located in the antrum. In either case, a separate independent carcinoma may be present in the same stomach.

Clinical and roentgen features of the intestinal polyposis syndromes

The intestinal polyposis syndromes represent a challenging diagnostic problem for the radiologist. These syndromes include: familial multiple polyposis, Gardner's, Peutz-Jeghers, Turcot's, Cronkhite-Canada and juvenile polyposis. The polyposis syndromes can usually be differentiated from one another on the basis of the clinical history, examination of the mucocutaneous tissues and roentgen findings. Numerous other conditions, however, may mimmic a polyposis syndrome, and must be considered in the differential diagnosis.

Perifollicular fibromatosis cutis with polyps of the colon--a cutaneo-intestinal syndrome sui generis

In the present study, a peculiar fibromatosis cutis in two siblings has been reported the dermatosis being characterized by innumerable perifollicular fibromas on face, neck and trunk as well as multiple fibromata pendulantia. Since the father allegedly had skin lesions resembling those of his two affected children, an inherited condition is assumed for the disease manifesting itself rather late in age. In the female patient, several adenomatous colon polyps one being transformed into carcinoma were found. Since the association of distinct epithelial and mesenchymal tumours of the skin and the cranial bones with multiple colon polyps is typical for Gardner's syndrome, we have discussed in detail the possiblity of an unknown variant of it. On the other hand, most features of Gardner's syndrome (cutaneous and subcutaneous epidermoid cysts, desmoid tumours, generalized osteomas, a marked multitude of colon polyps, early manifestation of skin and bone changes) were absent in both cases whereas, to our knowledge, in Gardner's syndrome perifollicular fibromas have never been seen. Since perifollicular fibromas are organoid tumours of the mesenchymal hair sheath being clearly defined both clinically and histologically, they must not be confused with the equally well characterized cutaneous tumours of Gardner's syndrome. We are prone to assume that the (irregular?) ASSOCAITION OF MULTIPLE PERIFOLLICULAR FIBROMAS AND COLON POLYPS Represents a distinct nosological entity neither identical with Gardner's syndrome nor with any other known dermo-intestinal syndrome. Thus, perifollicular fibromatosis should alert the dermatologist to consider periodic thorough examination for intestinal polyps the more as they may change into malignant growth.

Hereditary polypoid diseases of the gastrointestinal tract: a working classification

Almost all published cases of hereditary intestinal polypoid diseases can be meaningfully classified into a relatively few distinct syndromes including familial polyposis of the colon, Peutz-Jeghers syndrome, and juvenile polyposis. Familial polyposis is characterized by the development of numerous adenomatous polyps of the colon and subsequent development of colorectal carcinoma in nearly all patients. Extracolonic manifestations are common but do not influence the premalignant nature of this syndrome. Peutz-Jeghers syndrome is identifiable by a combination of circumoral melanin pigmentation and hamartomatous polyps. These polypoid lesions have an unusually wide distribution and may occur in the respiratory, gastrointestinal, or genitourinary tract. There is a small but definite increased incidence of gastrointestinal cancer in these patients. Juvenile polyposis presents a more variable spectrum. In one form there is extensive intestinal involvement leading to diarrhea, inanition, and increased susceptibility to infection. Another form is limited to the colon and easily confused with familial polyposis. With the third form, there is involvement of the stomach, intestines, and colon, which makes it easily mistaken for the Peutz-Jeghers syndrome.