The utility of a novel antibody in the pathological diagnosis of pancreatic acinar cell carcinoma.
OBJECTIVE
Acinar cell carcinomas (ACCs) are rare tumours of the exocrine pancreas accounting for about 1-2% of all pancreatic neoplasms in adults. It is therefore difficult to come across a large number of ACC cases in a single medical institution, and only a few serial studies have been published. Since ACCs present a wide variety of morphological patterns, immunohistochemical analysis is useful. In this study, the authors established a novel monoclonal antibody 2P-1-2-1 by means of a subtractive immunisation method.


METHODS
Immunohistochemical staining was performed using 50 primary pancreatic tumors, including 7 ACCs, 7 neuroendocrine tumours (NETs), 5 solid-pseudopapillary neoplasms (SPNs), and 31 ductal carcinomas and organs other than the pancreas.


RESULTS
Non-neoplastic acinar cells were stained diffusely, but epithelial cells of the pancreatic duct and the islets of Langerhans were not stained. In pancreatic tumours, all the seven ACCs were diffusely positive for the 2P-1-2-1 antibody. However, no positive staining was found in other pancreatic tumours including NETs, SPNs and ductal adenocarcinomas. The sensitivity and specificity of the 2P-1-2-1 antibody for ACCs were both 100%. In other organs studied, positive staining was observed only in the ectopic pancreas.


CONCLUSIONS
It was shown that the 2P-1-2-1 antibody specifically stained the pancreatic acinar cells and tumours of acinar cell origin, such as ACCs. Although it remains unclear at this time to which proteins the monoclonal antibody 2P-1-2-1 is directed, it is suggested to be useful for the pathological diagnosis of ACCs and for the exclusion of other pancreatic tumours.
Department of Pathology, Kurume University School of Medicine, Kurume, Japan.
Makiko
M
Yasumoto
Masato
M
Hamabashiri
Jun
J
Akiba
Sachiko
S
Ogasawara
Yoshiki
Y
Naito
Tomoki
T
Taira
Masamichi
M
Nakayama
Aya
A
Daicho
Fumio
F
Yamasaki
Kazuhide
K
Shimamatsu
Yusuke
Y
Ishida
Ryohei
R
Kaji
Yoshinobu
Y
Okabe
Osamu
O
Nakashima
Koichi
K
Ohshima
Manabu
M
Nakashima
Michio
M
Sata
Hirohisa
H
Yano
D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived; D018267:Carcinoma, Acinar Cell / Q000473:pathology*; D016022:Case-Control Studies; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010189:Pancreatic Juice / Q000276:immunology; D010190:Pancreatic Neoplasms / Q000473:pathology*
D058846:Antibodies, Monoclonal, Murine-Derived; C571902:monoclonal antibody 2P-1-2-1