Intraductal papillary mucinous neoplasms of the pancreas showing fistula formation into other organs.
BACKGROUND
This study assessed the mechanism of fistula formation in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.


METHODS
A total of 274 patients with IPMN who had been diagnosed by endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography (EUS) at our center were enrolled. The patients with IPMN which had fistula formation into other organs were investigated retrospectively as to (1) clinical prevalence and the organs penetrated by IPMN, (2) analysis of the mechanism of fistula formation by immunohistopathological study, (3) efficacy of EUS in progression assessment, and (4) prognosis.


RESULTS
Among the subjects, fistula formation into other organs was observed in 18 patients (6.6%) and into 28 organs. There were 7 patients (39%) in whom multiple organs were penetrated. Of 16 patients who had undergone investigation of the expression of mucin markers, 94% had an intestinal-type tumor. Of 9 patients who had undergone surgery or autopsy, 67% showed mechanical penetration without invasion around the fistula. Only papillary protrusions were seen by EUS in 4 of these patients with noninvasive papillary adenocarcinoma showing mechanical penetration. All 5 patients who had pancreatic parenchymal invasion showed a mass with a mixed-echo pattern in addition to papillary protrusions shown by EUS, corresponding to colloid carcinoma.


CONCLUSIONS
There were 2 processes in the development of fistulas in IPMN. Of those patients showing fistula formation, 94% had intestinal-type IPMN, and 67% showed mechanical penetration. Delineation of a mass with the mixed-echo pattern suggested an invasive penetration due to colloid carcinoma.
Kobayashi
Go
G
Department of Gastroenterology, Sendai City Medical Center, 5-22-1 Tsurugaya, Miyagino-ku, Sendai, Miyagi, Japan. go-koba@mua.biglobe.ne.jp
Fujita
Naotaka
N
Noda
Yutaka
Y
Ito
Kei
K
Horaguchi
Jun
J
Obana
Takashi
T
Koshida
Shinsuke
S
Kanno
Yoshihide
Y
Yamashita
Yasunobu
Y
Kato
Yuhei
Y
Ogawa
Takahisa
T
Oikawa
Masaya
M
Tsuchiya
Takashi
T
Sawai
Takashi
T
D002288:Adenocarcinoma, Mucinous / Q000150:complications* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000150:complications* / Q000473:pathology; D002291:Carcinoma, Papillary / Q000150:complications* / Q000473:pathology; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods; D019160:Endosonography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010185:Pancreatic Fistula / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000150:complications* / Q000473:pathology; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies