Ring-enhancement pattern on contrast-enhanced CT predicts adenosquamous carcinoma of the pancreas: a matched case-control study.
OBJECTIVE
Adenosquamous carcinoma of the pancreas (ASC) is a rare malignant neoplasm of the pancreas, exhibiting both glandular and squamous differentiation. However, little is known about its imaging features. This study examined the imaging features of pancreatic ASC.


METHODS
We evaluated images of contrast-enhanced computed tomography (CT) and endoscopic ultrasonography (EUS). As controls, solid pancreatic neoplasms matched in a 2:1 ratio to ASC cases for age, sex and tumor location were also evaluated.


RESULTS
Twenty-three ASC cases were examined, and 46 solid pancreatic neoplasms (43 pancreatic ductal adenocarcinomas, two pancreatic neuroendocrine tumors and one acinar cell carcinoma) were matched as controls. Univariate analysis demonstrated significant differences in the outline and vascularity of tumors on contrast-enhanced CT in the ASC and control groups (P < 0.001 and P < 0.001, respectively). A smooth outline, cystic changes, and the ring-enhancement pattern on contrast-enhanced CT were seen to have significant predictive powers by stepwise forward logistic regression analysis (P = 0.044, P = 0.010, and P = 0.001, respectively). Of the three, the ring-enhancement pattern was the most useful, and its predictive diagnostic sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of ASC were 65.2%, 89.6%, 75.0% and 84.3%, respectively.


CONCLUSIONS
These results demonstrate that presence of the ring-enhancement pattern on contrast-enhanced CT is the most useful predictive factor for ASC.
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan. Electronic address: hiroshi.imaoka.md@me.com.
Hiroshi
H
Imaoka
Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
Yasuhiro
Y
Shimizu
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Nobumasa
N
Mizuno
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Kazuo
K
Hara
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Susumu
S
Hijioka
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Masahiro
M
Tajika
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Tsutomu
T
Tanaka
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Makoto
M
Ishihara
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Takeshi
T
Ogura
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Tomohiko
T
Obayashi
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Akihide
A
Shinagawa
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Masafumi
M
Sakaguchi
Department of Diagnostic and Interventional Radiology, Aichi Cancer Center Hospital, Nagoya, Japan.
Hidekazu
H
Yamaura
Department of Diagnostic and Interventional Radiology, Aichi Cancer Center Hospital, Nagoya, Japan.
Mina
M
Kato
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Yasumasa
Y
Niwa
Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
Kenji
K
Yamao
D000328:Adult; D000368:Aged; D018196:Carcinoma, Adenosquamous / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D019160:Endosonography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D015999:Multivariate Analysis; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed / Q000379:methods*
Adenosquamous carcinoma of the pancreas (ASC); Contrast-enhanced computed tomography (CT); Endoscopic ultrasonography (EUS); Matched case-control study; Pancreatic ductal adenocarcinoma (PDAC)