Sporadic fundic gland polyps: an immunohistochemical study of their antigenic profile.
Fundic Gland Polyps (FGPs) are small sessile (2-5 mm), usually multiple polyps arising in the gastric, acid-secreting mucosa of disputed histogenesis. They have been described in a sporadic form, prevalently in middle aged females, or associated with familial adenomatosis coli-Gardner's syndrome. We performed an immunohistochemical study on 24 sporadic FGPs, using monoclonal antibodies (MAbs) against differentiation markers, class II MHC antigens (HLA-DR), oncofetal and proliferation antigens, aimed to characterize the antigenic profile of the polyps. A preliminary cytogenetic study on five polyps was also done, using an in situ culture method after collagenase treatment. Cytokeratins 8-18 (CAM 5.2 MAb) and 20 (IT-Ks 20.8 MAb), Epithelial Membrane Antigen (EMA) and Chromogranin A were normally expressed by FGPs. FGPs did not express HLA II DR. FGPs did not react with an anti-CEA MAb (F6), but they were frequently positive (22/24, 91.6%) with B72.3 MAb (reacting with the cancer-associated mucin epitope sialyl-Tn). The PC10 MAb (against PCNA or cyclin) showed enhanced expression in the deep glandular-cystic compartment of FGPs; the PCNA index of FGPs was significantly higher than in normal fundic mucosa. The cytogenetic study on the 5 cases analysed, revealed a normal karyotype. We have demonstrated that FGPs express in the paranuclear zone the sialyl-Tn epitope, a side-chain sugar normally masqued in adult gastric mucins, thus revealing an alteration in mucin synthesis; FGPs' higher proliferation index as compared with normal fundic mucosa supports the hypothesis of their hyperproliferative nature.
Department of Pathology, Legnano General Hospital, Italy.
P
P
Declich
G
G
Isimbaldi
M
M
Sironi
C
C
Galli
A
A
Ferrara
S
S
Caruso
M P
MP
Baldacci
S
S
Stioui
O
O
Privitera
G
G
Boccazzi
S
S
Federici
D000951:Antigens, Neoplasm / Q000032:analysis* / Q000276:immunology*; D005260:Female; D005748:Gastric Fundus / Q000737:chemistry / Q000276:immunology* / Q000473:pathology; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011127:Polyps / Q000737:chemistry / Q000276:immunology* / Q000473:pathology; D013274:Stomach Neoplasms / Q000737:chemistry / Q000276:immunology* / Q000473:pathology
D000951:Antigens, Neoplasm; D006684:HLA-DR Antigens