Background

This is a rare polyp that occurs throughout the gastrointestinal tract. For many years it was thought that this polyp was benign. Recently, however, due to work by pathologists, it is becoming increasingly evident that some of these polyps have the potential for malignant change.

OUTLINE

Pathogenesis
Histopathological Features and Variants
Differential Diagnosis
Prognosis and Treatment
Commonly Used Terms

PATHOGENESIS

CHARACTERIZATION

Multiple juvenile polyposis. A study of the pathogenesis of juvenile polyps and their relationship to colonic adenomas. Lipper S, Kahn LB, Sandler RS, Varma V.

Hum Pathol 1981 Sep;12(9):804-13 Abstract quote Solitary juvenile polyps are common lesions whose pathogenesis is poorly understood. Multiple juvenile polyposis is characterized by large numbers of these lesions either confined to the colon or throughout the gastrointestinal tract. A study of two cases of multiple juvenile polyposis provided fresh insight into the pathogenesis of juvenile polyps and their relationship to colonic adenomas. Mucosal ulceration in very early lesions, together with glandular epithelial calcification, suggested that impaired cell renewal resulting from disturbed regenerative kinetics may predispose to surface epithelial erosion, setting in motion a cycle of ulceration, inflammation, and granulation tissue formation. We postulate that a dyskinetic continuum may link juvenile, "metaplastic," and adenomatous polyps. The finding in our second case of multiple adenomatous lesions, including a villoglandular polyp, emphasizes the neoplastic potential of juvenile polyposis.

HISTOLOGICAL TYPES	CHARACTERIZATION
GENERAL
Atypical juvenile polyposis. Grigioni WF, Alampi G, Martinelli G, Piccaluga A.	Histopathology 1981 Jul;5(4):361-76 Abstract quote 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.
Juvenile and inflammatory polyps of the colon--a histological and histochemical study. Franzin G, Zamboni G, Dina R, Scarpa A, Fratton A.	Histopathology 1983 Sep;7(5):719-28 Abstract quote A light microscopy and histochemical study of 24 juvenile and 27 inflammatory polyps showed that both may derive from inflammatory processes. Granulation tissue, secondary to spontaneous local inflammation or due to surgical procedures may subsequently be covered by regenerating epithelium which lines haemorrhagic cavities and mucus lakes to form irregular, elongated and cystic glands, which are characteristic of juvenile polyps. Both juvenile and inflammatory polyps showed cystic, metaplastic and 'transitional-type' glands. The mucin distribution was identical in both types of polyps. All these findings suggest a common origin of the polyps. The presence of 'transitional-type' glands seems to confirm these as a secondary regenerative phenomenon rather than pre-neoplastic, although dysplastic changes in juvenile polyps have been described. It is suggested that both the juvenile and inflammatory polyps may undergo dysplasia only in genetically predisposed subjects. However, this event seems to be very rare.
Colorectal juvenile polyps: an epidemiological and histopathological study of 144 cases in Jordanians. Dajani YF, Kamal MF.	Histopathology 1984 Sep;8(5):765-79 Abstract quote 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 (coli)--high incidence of dysplastic epithelium. Vaiphei K, Thapa BR. Department of Histopathology, Pgimer, Chandigarh, India.	J Pediatr Surg 1997 Sep;32(9):1287-90 Abstract quote BACKGROUND: A juvenile polyp is a commonly seen condition in the pediatric age group as an etiological factor for rectal bleeding. The histological appearance was considered to be nonneoplastic and was distinguished from other neoplastic polyps. But this concept has been changing over the years as higher incidence of colonic and rectal adenocarcinomas are seen in patients with both familial and nonfamilial polyposis. The malignant potential was first recognized in 1980. METHODS: With this background knowledge, the authors carried out a retrospective study of juvenile polyposis patients, who underwent full-length colonoscopy and upper gastrointestinal endoscopy to assess the presence of dysplastic epithelium. There were eleven cases of nonfamilial juvenile polyposis (one case with foregut polyps). RESULTS: Ten cases showed presence of dysplastic epithelium in focal areas in the juvenile polyps, mild in degree in three cases and moderate in degree in 10 cases, with focal severe degree in two. CONCLUSION: All polyps of juvenile polyposis after polypectomy must be subjected to histopathologic examination to determine the presence of dysplastic/adenomatous epithelium.
VARIANTS

DIFFERENTIAL DIAGNOSIS	KEY DIFFERENTIATING FEATURES
CRONKHITE-CANADA POLYPS
The pathology of Cronkhite-Canada polyps. A comparison to juvenile polyposis. Burke AP, Sobin LH. Department of Gastrointestinal Pathology, Armed Forces Institute of Pathology, Washington, D.C. 20306-6000.	Am J Surg Pathol 1989 Nov;13(11):940-6 Abstract quote We studied Cronkhite-Canada (CC) polyps from nine patients, and compared them to gastric and colonic juvenile and gastric hyperplastic polyps. The CC polyp is characterized by its broad sessile base, expanded edematous lamina propria, and cystic glands. Similar features are found in the lesions of juvenile polyposis and gastric hyperplastic polyps. The only reliable distinction between CC and colonic juvenile polyposis was the pedunculated growth of the latter; however, this feature did not hold for gastric lesions. Unlike CC polyps, juvenile polyps sometimes have areas of dysplasia, but this is not typical. Therefore the diagnosis of CC polps, especially when located in the stomach, requires the presence of the ectodermal changes characteristic of this syndrome

 

PROGNOSIS AND TREATMENT	CHARACTERIZATION
PROGNOSTIC FACTORS
Juvenile polyposis--a precancerous condition. Jass JR, Williams CB, Bussey HJ, Morson BC. St Mark's Hospital, London, UK.	Histopathology 1988 Dec;13(6):619-30 Abstract quote Clinical and pathological findings in 87 patients with juvenile polyposis have been reviewed; 1032 polyps were available from 80 of these patients; 840 were typical spherical juvenile polyps whereas 169 differed in being multilobulated or showing a villous configuration; 79 (46.7%) of the latter contained foci of epithelial dysplasia whereas only 76 (9.0%) of the typical juvenile polyps were dysplastic. The series also included 21 adenomas and two hyperplastic (metaplastic) polyps. The demonstration of dysplasia provides a histogenetic mechanism for the evolution of colorectal cancer from hamartomatous polyps; 18 juvenile polyposis patients have developed colorectal cancer at a mean age of 34 years (range 15-59). The clinical outcome was generally poor. No clinical or pathological distinction could be made between polyposis patients with and without colorectal cancer. Thus, the development of cancer in juvenile polyposis appears to be a random event. A working definition of juvenile polyposis is provided: (1) more than five juvenile polyps of the colorectum; and/or (2) juvenile polyps throughout the gastrointestinal tract; and/or (3) any number of juvenile polyps with a family history of juvenile polyposis. It is suggested that the condition should be treated as seriously as familial adenomatous polyposis except that regular colonoscopic surveillance may obviate the need for prophylactic colectomy.
Colorectal neoplasia in juvenile polyposis or juvenile polyps. Giardiello FM, Hamilton SR, Kern SE, Offerhaus GJ, Green PA, Celano P, Krush AJ, Booker SV. Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland 21205.	Arch Dis Child 1991 Aug;66(8):971-5 Abstract quote Juvenile (retention) polyps are usually solitary lesions in the colorectum but may be multiple in juvenile polyposis. The association between juvenile polyps and colorectal neoplasia is controversial. We present three patients with juvenile polyposis who had colorectal adenomas or adenomatous epithelium in juvenile polyps at ages 3, 4, and 7 years. In a retrospective study of 57 additional patients with one or more juvenile polyps, 10 patients (18%) had colorectal neoplasia including three with adenocarcinoma, two with tubular adenoma, and six with adenomatous epithelium in a juvenile polyp (one had both adenomatous epithelium and an adenocarcinoma). Nine of these 10 patients had juvenile polyposis defined by the presence of at least three juvenile polyps; and eight of the nine had a family history of juvenile polyps. Colorectal neoplasia occurred at young age (mean (SEM) 37 (5) years). Our findings suggest that patients with juvenile polyps who have three or more juvenile polyps or a family history of juvenile polyps should undergo surveillance for colorectal neoplasia.
Solitary juvenile polyps: not a marker for subsequent malignancy. Nugent KP, Talbot IC, Hodgson SV, Phillips RK. Department of Pathology, St. Marks Hospital, London, England.	Gastroenterology 1993 Sep;105(3):698-700 Abstract quote BACKGROUND: Solitary juvenile polyps are considered benign. In contrast, juvenile polyposis is associated with malignancy and poor long-term outcome. Recent reports suggest that solitary juvenile polyps may also undergo both adenomatous and malignant change. The long-term outcome of patients with solitary juvenile polyps is unknown. Patients are treated conservatively and discharged from follow-up. The present study was designed to examine the incidence of cancer and mortality of these patients, comparing their life expectancy with that of the general population. METHODS: The outcome of 82 patients with a solitary juvenile polyp between 1958 and 1982 was examined by life table analysis. Patients were traced through the Office of Population Censuses and Surveys for death and cancer registration. Patients were compared with an age- and sex-matched group of the general population. RESULTS: The relative risk of dying for patients who have previously had a solitary juvenile polyp in comparison with the general population was found to be 0.66 (95% confidence interval, 0.34-1.14). There was only one case of colorectal cancer. CONCLUSIONS: Patients with a solitary juvenile polyp are not at increased risk of dying of or developing colorectal cancer and do not require further follow-up or investigations.
What is a juvenile polyp? An analysis based on 21 patients with solitary and multiple polyps. Coffin CM, Dehner LP. Division of Pediatric Pathology, Primary Children's Medical Center, University of Utah Health Sciences, Salt Lake City 84113, USA.	Arch Pathol Lab Med 1996 Nov;120(11):1032-8 Abstract quote BACKGROUND: Juvenile polyps, the most common pediatric gastrointestinal polyp, have been typically characterized as either hamartomatous overgrowths or reactive inflammatory proliferations. Recent observations of excessive colonic and gastric carcinoma and dysplasia in juvenile polyposis have prompted reclassification of this entity as a premalignant condition. The relationship between solitary or multiple juvenile polyps and malignancy is less clear. PATIENTS AND METHODS: To further investigate the frequency and significance of dysplasia in juvenile polyps, we analyzed 28 polyps from 21 patients histologically and immunohistochemically for substances previously associated with neoplastic transformation in the colorectal adenomacarcinoma sequence. RESULTS: Fifteen patients had a solitary polyp, two had 2 to 9 polyps, and four had polyposis with 10 or more polyps. Most polyps exhibited inflammatory or regenerative atypia. Foci of dysplasia were noted in polyps from 11 patients, and immunoreactivity for p53 and human chorionic gonadotropin was present in 12 of the 28 polyps each. These findings were all more frequent in the polyposis specimens than in solitary polyps. CONCLUSIONS: These observations, in combination with reports of an increased risk of carcinoma in juvenile polyposis, suggest that juvenile polyps are lesions with a potential for neoplastic and malignant transformation, although they share features of an inflammatory reactive process. The implications for clinical management of patients and pathologic evaluation of juvenile polyps warrant further investigation.
Symptomatic colonic polyps in childhood: not so benign. Hoffenberg EJ, Sauaia A, Maltzman T, Knoll K, Ahnen DJ. Department of Pediatrics, University of Colorado School of Medicine, and The Children's Hospital, Denver, USA.	J Pediatr Gastroenterol Nutr 1999 Feb;28(2):175-81 Abstract quote BACKGROUND: The clinical spectrum of symptomatic polyps and the frequency of familial polyposis is not well defined in children. In the present study, a series of children with juvenile polyposis coli (JPC) and non-JPC polyps were studied. METHODS: Children with symptomatic colonic polyps and negative family history of polyps were ascertained by review of endoscopic records. Juvenile polyposis coli was defined as 10 or more juvenile polyps or any juvenile polyp in a relative of an index case of JPC. Polyps were tested for Ki-ras mutations, p53 overexpression, and aneuploidy. RESULTS: Seventy-eight children (age range, 0.4-18 years) were identified, all evaluated for lower gastrointestinal bleeding. Nine (12%) had JPC, 66 (84%) had isolated juvenile polyps, and 3 (4%) had other types of polyps. The JPC and non-JPC groups were similar in age (p = 0.4) and symptom duration (p = 0.3). The JPC group had more polyps (p = 0.0001), and greater likelihood of anemia (p = 0.01), polyps with adenomatous change (p = 0.03), and right-colon polyps (p = 0.001). In three of eight JPC families, polyps were identified in asymptomatic first-degree relatives. No abnormalities in Ki-ras, p53, or aneuploidy were identified. CONCLUSIONS: Juvenile polyposis coli is common in children with symptomatic polyps, and is associated with anemia, right-colon polyps, and adenomas. The risk of polyps and of colorectal cancer in relatives of persons with JPC requires further study.

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Gastrointestinal Tract

Last Updated 8/7/2002

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