Mode of progression of intraductal papillary-mucinous tumor of the pancreas: Analysis of patients with follow-up by EUS

Go Kobayashi, Naotaka Fujita, Yutaka Noda, Kei Ito, Jun Horaguchi, Osamu Takasawa, Satoshi Akaishi, Takashi Tsuchiya, Masao Kobari

Research output: Contribution to journalArticlepeer-review

102 Citations (Scopus)


Background: We investigated the mode of progression of intraductal papillary-mucinous neoplasm of the pancreas (IPMN) in patients who underwent follow-up in order to elucidate the characteristics of malignancy and to establish an effective treatment strategy. Methods: Fifty-one patients with IPMN (branch-duct type, 47; main-duct type, 4) who had undergone follow-up study by endoscopic ultrasonography (EUS) were included (mean follow-up duration, 41.0 ± 32.3 months; average number of EUS examinations performed during follow-up, 4.4). Chronological changes in EUS findings and histological findings of resected specimens were evaluated. Results: Of the patients with the branch-duct type, only 2% showed enlargement of the dilated branches. In the main-duct-type group, an increase in size of the main pancreatic duct (MPD) was observed in 75% of the patients. In 14 patients with papillary protrusions, an increase in size and lateral spread was observed in 71% and 43%, respectively. No patients developed invasive cancer. In 15 patients who had thick septum-like structures (TSS), the development of papillary protrusions and that of invasive cancer were observed in 53% and 13%, respectively. Twenty-nine patients who had thin septum-like structures showed no change. Two patients with dense multilocular large cysts and TSS developed invasive cancer without change in the cystic lesions. One patient developed carcinoma with multifocal stromal invasion. Conclusions: Patients with branch-duct type IPMNs without papillary protrusions or TSS are not immediate candidates for surgery. Those who have small papillary protrusions have a benign course. It is recommended that patients with the large branch-duct type with TSS should undergo surgery. Attention should be paid to the entire pancreas when performing follow-up examinations in patients with branch-duct type IPMN, as invasive ductal adenocarcinoma can develop at a site in the pancreas different from that of the IPMN.

Original languageEnglish
Pages (from-to)744-751
Number of pages8
JournalJournal of gastroenterology
Issue number7
Publication statusPublished - 2005 Jul 1
Externally publishedYes


  • Endoscopic ultrasonography
  • Intraductal papillary-mucinous neoplasm
  • natural history
  • pancreatic tumor

ASJC Scopus subject areas

  • Gastroenterology


Dive into the research topics of 'Mode of progression of intraductal papillary-mucinous tumor of the pancreas: Analysis of patients with follow-up by EUS'. Together they form a unique fingerprint.

Cite this