Massive Gastric Juvenile Polyposis: A Clinicopathologic Study Using SMAD4 Immunohistochemistry.
OBJECTIVE
Juvenile polyps involving the stomach are uncommon. Massive gastric juvenile polyposis is even rarer.


METHODS
We describe the clinicopathologic features of nine cases of massive gastric juvenile polyposis.


RESULTS
All patients had anemia; four had hypoalbuminemia. The polyps were composed predominantly of dilated crypts lined by columnar epithelium and abundant edematous stroma with mixed inflammatory infiltrates. One patient had a poorly differentiated adenocarcinoma, arising in juvenile polyp-associated intraepithelial neoplasia. A second patient had a well-differentiated intramucosal adenocarcinoma arising in a juvenile polyp with high-grade dysplasia. Three of our cases had polyposis restricted to the stomach. Six (66.6%) had loss of SMAD4 immunoreactivity, making them subject to severe bleeding and hypoproteinemia, as well as developing severe dysplasia or adenocarcinoma.


CONCLUSIONS
SMAD4 immunohistochemstry is a helpful ancillary diagnostic test in cases of suspected juvenile polyposis syndrome involving the stomach.
From the Department of Pathology, University of Washington School of Medicine, Seattle.
Margaret E
ME
Lawless
From the Department of Pathology, University of Washington School of Medicine, Seattle.
Daniel L
DL
Toweill
From the Department of Pathology, University of Washington School of Medicine, Seattle.
Kim D
KD
Jewell
Department of Pathology, Yale University School of Medicine, New Haven, CT.
Dhanpat
D
Jain
Department of Pathology, University of Arkansas, Little Rock, AR.
Laura
L
Lamps
Department of Pathology, University of Pittsburgh, PA.
Alyssa M
AM
Krasinskas
From the Department of Pathology, University of Washington School of Medicine, Seattle.
Paul E
PE
Swanson
From the Department of Pathology, University of Washington School of Medicine, Seattle.
Melissa P
MP
Upton
From the Department of Pathology, University of Washington School of Medicine, Seattle.
Matthew M
MM
Yeh
D000230:Adenocarcinoma / Q000175:diagnosis / Q000235:genetics / Q000473:pathology*; D018256:Adenomatous Polyps / Q000175:diagnosis / Q000235:genetics / Q000473:pathology*; D000328:Adult; D004252:DNA Mutational Analysis; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D044483:Intestinal Polyposis / Q000151:congenital* / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009386:Neoplastic Syndromes, Hereditary / Q000175:diagnosis / Q000235:genetics / Q000473:pathology*; D012189:Retrospective Studies; D051901:Smad4 Protein / Q000235:genetics / Q000378:metabolism*; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000473:pathology*; D055815:Young Adult
C497796:SMAD4 protein, human; D051901:Smad4 Protein
Immunohistochemistry; Juvenile polyps; Massive gastric juvenile polyposis; SMAD4