[597] Morphologic Findings in a Novel Familial Polyposis Syndrome.

Phyu P Aung, Langan Russell, Douglas Weinstein, Theo Heller, David Kleiner, Udai Kammula, Udo Rudloff, Itzhak Avital, Martha Quezado. National Cancer Institute, Bethesda, MD; NIDDK, Bethesda, MD

Background: Familial Polyposis Syndromes (FPS) are gastrointestinal disorders characterized by diffuse and regional polyposis and are often associated with systemic manifestations including skin lesions and non-GI malignancies. Known syndromes include Familial Adenomatous Polyposis, Juvenile polyposis, and the harmatomatous polyposes. Specific genetic changes associated with FPS include APC and MYH gene mutations. We now describe the morphologic findings of polyps encountered in family members of an as yet unidentified gastric FPS.
Design: Specimens from patients with gastric polyposis enrolled in an NIH IRB approved protocol were evaluated. Multiple HE sections were reviewed along with p53, MIB-1, and E-cadherin immunostains when available. Six family members have undergone genetic testing using 1x106 SNP array.
Results: Specimens were available in 10 patients (2 male, 8 female), ranging in age from 18 to 64. None had systemic manifestations. 8 had biopsies performed and 2 had total gastrectomy. On endoscopy, 1 had colonic polyps and 6 had gastric polyps and in 3, there were no lesions. Biopsy findings included: fundic gland polyps (1), colonic tubular adenoma (1), colonic hyperplastic polyp (1) and no lesions (5). Gastrctomy specimens from the 2 patients showed similar findings: multiple (>100) fundic gland like polyps with and without dysplasia (low and high grade) and flat mucosa with dysplasia (tubular adenoma like). Dysplastic lesions showed a high proliferative index with MIB-1 and scattered p53 positive cells. E-cadherin stains showed normal staining. Genetic testing using 1x106 SNP array was negative for known genetic abnormalities.
Conclusions: We suggest that fundic gland like polyps with dysplasia and flat gastric mucosal dysplasia are the hallmark of an as yet unidentified novel gastric FPS.
Category: Gastrointestinal

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 148, Tuesday Morning

 

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