Colonic and Duodenal Flat Adenomas in Children with Classical Familial Adenomatous Polyposis

Abstract

Flat adenomas of the colon and duodenum have been described as associating with familial adenomatous polyposis (FAP), its attenuated variant, and the so-called hereditary nonpolyposis colorectal cancer. There seem to be no report on the occurrence of flat adenomas in pediatric patients with family history of FAP. We are reporting 4 children from 2 cancer-prone families in whom colonic and duodenal moderately dysplastic flat adenomas were found. Gastrointestinal endoscopy and biopsies were performed in 3 female siblings (7, 9, and 11 years old) and 1 male (9 years old) when referred for screening owing to familial history of bowel cancer (family 1) or evidence of bilateral congenital hypertrophy of the retinal pigment epithelium (CHRPE), which is known to be associated with FAP (family 2). Endoscopic visualization of the mucosa was improved by use of 0.2% indigo carmine solution spray. Biopsies were routinely processed for H&E and immunohistochemistry staining. Present patients were asymptomatic, with the exception of 2 weeks rectal bleeding in 1 of them. The colonic videoendoscopy showed in 2/3 siblings hundreds of flat or slightly raised plaques less than 1 cm in diameter as well as some classic polyps throughout the colon. The other sibling showed 40 flat-topped lesions with minimal elevation and central umbilication in the cecum. Upper endoscopy demonstrated a few flat lesions in the nonperiampullary area of the duodenum in 2/4 patients. The colonic videoendoscopy performed on the 9-year-old boy revealed multiple small sessile polyps. Microscopic study demonstrated tubular adenomas with a few neoplastic crypts, slight disarray of the overall architecture, and moderate (low-grade) dysplasia of the epithelium. These features were more obvious at the center and superficial areas of the adenomas. The 4 children had multiple flat adenomas of the colon and duodenum (2/4) matching with those described in adult patients. Flat adenomas in the context of FAP probably represent early stages of the adenoma development. Careful endoscopic-histologic correlation may result in increasing recognition of these lesions at the pediatric age.

Keywords

familial adenomatous polyposis flat adenoma pediatrics

Get full access to this article

View all access options for this article.

References

Muto T , Kamiya J , Sawada T , et al. Small “flat adenoma” of the large bowel with special reference to its clinicopathologic features. Dis Colon Rectum 28:847–851, 1985

Cooper H. Intestinal neoplasms In: Sternberg S (ed.). Diagnostic surgical pathology. Lippincott Williams & Wilkins, Philadelphia, 1999, pp. 1413–1467

Lynch H , Smyrk T , Lanspa S , Marcus J , Kriegler M , Lynch J , Appelman H. Flat adenomas in a colon cancer-prone kindred. J Natl Cancer Inst 80:278–282, 1988

Lynch H , Smyrk T , Lanspa S , et al. Phenotypic variation in colorectal adenoma/cancer expression in two families. Hereditary flat adenoma syndrome. Cancer 66:909–915, 1990

Lynch H , Smyrk T , Watson P , et al. Hereditary flat adenoma syndrome: A variant of familial adenomatous polyposis? Dis Colon Rectum 35:411–421, 1992

Lynch H , Smyrk T , McGinn T , et al. Attenuated familial adenomatous polyposis (AFAP). A phenotypically and genotypically distinctive variant of FAP. Cancer 76:2427–2433, 1995

Aaltonen L , Jass J , Howe J. Juvenile polyposis. In: Hamilton S , Aaltonen L , (eds.). World Health Organization Classification of tumours. Pathology and genetics of tumours of the digestive system. IARC Press, Lyon, 2000, pp. 130–132

Talbot I , Burt R , Jarvinen H , Thomas G . Familial adenomatous polyposis. In: Hamilton S , Aaltonen L , (eds.). World Health Organization Classification of tumours. Pathology and genetics of tumours of the digestive system. IARC Press, Lyon, 2000, pp. 120–125

Lowichik A , Jackson WA , Coffin Ch. Gastrointestinal polyposis in childhood: Clinicopathologic and genetic features. Pediatr Dev Pathol 6:371–391, 2003

10.

Spirio L , Olschwang S , Groden J , et al. Alleles of the APC gene: An attenuated form of familial polyposis. Cell 1993; 75: 951-957.

11.

Kubota O , Kino I . Minute adenomas of the depressed type in familial adenomatous polyposis of the colon. A pathway to ordinary polypoid adenomas. Cancer 72:1159–1164, 1993

12.

Kubota O , Kino I . Depressed adenomas of the colon in familial adenomatous polyposis. Histology, immunohistochemical detection of proliferating cell nuclear antigen (PCNA), and analysis of the background mucosa. Am J Surg Pathol 19:318–327, 1995

13.

Samowitz W , Randall B . The nonspecificity of histological findings reported for flat adenomas. Hum Pathol 26:571–573, 1995

14.

Lane N , Lev R . Observations of the origin of adenomatous epithelium of the colon. Serial section studies of minute polyps in familial polyposis. Cancer 16:751–754, 1963

15.

Talbot IC . Dysplasia in the lower gastrointestinal tract. In: Lowe D , Underwood JCE , (eds.). Recent advances in histopathology. Churchill Livingstone, London, 2001, pp. 211–225

16.

Wolber R , Owen D . Flat adenomas of the colon. Hum Pathol 22:70–74, 1991

17.

Watanabe T , Muto T , Sawada T , Miyaki M . Flat adenoma as a precursor of colorectal carcinoma in hereditary nonpolyposis colorectal carcinoma. Cancer 77:627–634, 1996

18.

Matsumoto T , Lida M , Nakamura S , et al. Depressed adenoma of the duodenum in patients with familial adenomatous polyposis. Endoscopic and immunohistochemical features. Cancer 86:1414– 1420, 1999

19.

Lanspa S , Rouse J , Smyrk T , Watson P , Jenkins J , Lynch H . Epidemiologic characteristics of the flat adenoma of Muto. A prospective study. Dis Colon Rectum 35:543–546, 1992

20.

Nomura M , Watari J , Yokota K , Saitoh Y , Obara T , Kohgo Y . Morphogenesis of nonpolypoid colorectal adenomas and early carcinomas assessed by cell proliferation and apoptosis. Virchows Arch 437:17–24, 2000

21.

Ramón G , Luna C , Valencia P . Poliposis múltiple. Experiencia en el Hospital Infantil de México Federico Gómez. Patología, 39:S8-S8 (abstract), 2001