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Intraductal tubular adenoma of the pancreas, pyloric gland type: a
clinicopathologic and immunohistochemical study of 6 cases.Am
J Surg Pathol. 2005 May;29(5):607-16.
The intraductal
tubular adenoma (ITA), pyloric gland type, of the pancreas is an
uncommon benign tumor, akin to the pyloric gland type adenoma of the
gallbladder. We report 6 cases of ITA of the pancreas: 3 male and 3
female aged 50 to 79 years (mean, 63.5 years; median, 65 years); all
were examined clinicopathologically. Four patients showed no symptoms,
but appetite loss and/or general fatigue presented in two. Grossly,
all tumors formed a localized polypoid mass protruding into the lumen
of the dilated pancreatic duct. Five of the six tumors were found
within the main duct, and the other arose within the branch duct of
the pancreas. Microscopically, the tumors were composed of closely
packed tubular glands resembling pyloric type glands. They were lined
by columnar or cuboidal epithelial cells with foci of mild to moderate
dysplastic change. In 2 cases, the adjacent pancreas showed foci of
intraductal papillary-mucinous adenoma. Histochemically, the tumors
largely showed neutral mucin with a lesser amount of acidic mucin made
up mainly of sialomucin. Endocrine cells were found in five tumors.
Immunohistochemically, all tumors were labeled with M-GGMC-1 and MUC6,
whereas MUC1 and MUC2 stains were negative. Pepsinogen II was positive
in 5 tumors; thus, the results displayed a pattern of differentiation
similar to those of ordinary gastric pyloric or metaplastic pyloric
glands. DPC4 expression was maintained in all tumors and p53-positive
nuclei were hardly encountered. All patients are alive with no
evidence of disease 3 to 10.5 years after surgical resection.
Pyloric gland-type
tubular adenoma superimposed on intraductal papillary mucinous tumor
of the pancreas. Pyloric gland adenoma of the pancreas.Virchows
Arch. 2002 Feb;440(2):205-8.
We report a
rare case of pyloric gland-type tubular adenoma of the main pancreatic
duct. It was a grossly visible polypoid nodule and was composed of
closely packed pyloric-type glands. This adenoma was present within an
intraductal papillary mucinous adenoma (IPMA). In this IPMA lesion,
aggregations of pyloric-type glands were occasionally observed, and
most of the cells including ductal lining cells expressed pyloric
gland-type mucin. The IPMA of the present case showed more extensive
pyloric gland metaplasia or differentiation than commonly noted in
IPMAs. We consider this pyloric gland-type tubular adenoma to be
derived from a selective growth of IPMA cells showing pyloric gland
metaplasia.
Pyloric gland
adenoma of the main pancreatic duct. Am
J Surg Pathol. 1999;23(2):227-31.
A case of a
pyloric gland type adenoma of the main pancreatic duct in a
69-year-old woman is reported. The tumor led to occlusion and cystic
dilatation of the main duct in the pancreatic tail. The surgical
resection specimen disclosed a polypoid, bilobed mass attached to the
wall of the main pancreatic duct by a thin fibrous stalk.
Light-microscopic examination revealed a well-demarcated nodule
composed of closely packed tubular glands lined by columnar, mucin-secreting
cells with abundant clear cytoplasm and basally oriented nuclei.
Focal, mild cytologic atypia was seen. Pyloric metaplasia and focal
papillary hyperplasia was present in the adjacent ductal epithelium.
Periodic acid-Schiff reactions, with and without diastase predigestion,
showed reactivity in the tubular glands, whereas alcian blue (pH 2.5)
was negative. Immunohistochemical stains for chromogranin, serotonin,
somatostatin, and gastrin failed to detect the respective antigens.
Genetic analysis using polymerase chain reaction with mutant
enrichment and allele specific oligonucleotide hybridization detected
a single mutation at codon 12 of K-ras, which changed the wild-type
glycine to arginine. This mutation is commonly found in invasive
pancreatic ductal carcinomas. Although tumors with microscopic and
immunohistochemical features consistent with pyloric gland adenoma
have been described in the gallbladder, to our knowledge, this is the
first reported case within the pancreatic ductal system. The finding
of a K-ras, codon 12 mutation and the presence of focal dysplasia may
denote neoplastic potential in association with this lesion.
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