Preoperative histological subtype classification of intraductal papillary mucinous neoplasms (IPMN) by pancreatic juice cytology with MUC stain.
OBJECTIVE
To prospectively evaluate the diagnostic value of preoperative histological subtyping of intraductal papillary mucinous neoplasms (IPMNs) by pancreatic juice cytology (PJC) with mucin (MUC) stain.


BACKGROUND
IPMNs are classified into four subtypes based on their histomorphology and mucin phenotype, and varied degrees of malignant nature and prognosis among these subtypes have been shown.


METHODS
The subjects were 36 patients with surgically confirmed IPMNs, who underwent PJC preoperatively by endoscopic retrograde cholangiopancreatography. Histological subtyping of cytological samples with or without MUC stain (MUC1, MUC2, and MUC5AC) was compared with that of resected specimens.


RESULTS
Histologically, low-grade dysplasia was found in 4 patients, intermediate in 10, high grade in 11, and invasive carcinoma in 11. Gastric, intestinal, pancreatobiliary, and oncocytic subtypes corresponded to 16, 14, 5, and 1 patient, respectively. The rate of high-grade dysplasia (HGD) and/or invasive IPMNs was 25% for gastric subtype, 85.7% for intestinal subtype, and 100% for both pancreatobiliary and oncocytic subtypes, showing a significant correlation between histological subtype and rate of HGD and/or invasive IPMN (P < 0.01 for gastric vs nongastric).Histological subtype was successfully diagnosed by PJC in 42% (15/36) without MUC stain, and the rate was significantly improved to 89% (32/36) with MUC stain (P < 0.01). The sensitivity, specificity, and overall accuracy of PJC with MUC stain were 86%, 100%, and 94% for intestinal subtype, respectively. When cytological grade was combined with MUC stain, the diagnosis of HGD/invasive IPMN showed 77.2% sensitivity, 85.7% specificity, and 80.5% accuracy.


CONCLUSIONS
Preoperative PJC with MUC stain proved to be highly reliable for identifying the histological subtype of IPMN and may provide useful information for deciding surgical indication.
Division of Endoscopy, Chiba Cancer Center, Chiba, Japan. thara@chiba-cc.jp
Taro
T
Hara
Dai
D
Ikebe
Akiko
A
Odaka
Kentaro
K
Sudo
Kazuyoshi
K
Nakamura
Hiroshi
H
Yamamoto
Makiko
M
Itami
Tetsushi
T
Hirata
Junya
J
Kashimura
Taketo
T
Yamaguchi
D002288:Adenocarcinoma, Mucinous / Q000473:pathology* / Q000601:surgery; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000473:pathology* / Q000601:surgery; D016009:Chi-Square Distribution; D002760:Cholangiopancreatography, Endoscopic Retrograde; D003952:Diagnostic Imaging; D005260:Female; D006801:Humans; D008297:Male; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D010189:Pancreatic Juice / Q000166:cytology*; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000601:surgery; D010641:Phenotype; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity