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Vol. 27, No. 2, 2010
Issue release date: June 2010
Dig Surg 2010;27:137–139
(DOI:10.1159/000286920)

Histopathology of the Minor Duodenal Papilla

Suda K.
Departments of Pathology, Tokyo-Nishi Tokushukai Hospital and Juntendo University, School of Medicine, Tokyo, Japan
email Corresponding Author

Abstract

The minor duodenal papilla, which is the orifice of the accessory, or dorsal, pancreatic duct/Santorini duct, mostly accompanied by pancreatic tissue, is situated about 2 cm ventroproximal to the major duodenal papilla. The patency of the terminal accessory pancreatic duct (APD) is recognized in about half or more of cases, and is related to the degree of fibrosis. The APD is lined with simple columnar epithelium and encircled by a smooth muscle layer. It is still controversial whether or not these muscle tissues comprise a sphincter muscle. Pancreatic tissue was found in about 80% of cases in the minor papilla. Among these cases, pancreatic tissue was continuous and/or closely related to the proper pancreas in about 40% of cases, and might have the same exocrine and endocrine morphologies/functions, suggesting that it is a portion of the dorsal pancreas and not an ectopic one. Endocrine cell micronests are frequently found in the ductal wall/surrounding area of the terminal APD, and predominantly consist of somatostatin- and/or pancreatic-polypeptide-containing cells. In cases of pancreas divisum, inadequate pancreatic juice drainage from the minor papilla might occur, resulting in dorsal pancreatitis. In the minor papilla, all ductal tumors may occur, such as an intraductal papillary mucinous neoplasms and invasive ductal carcinoma, but carcinoid tumors are rare.


 Outline


 goto top of outline Key Words

  • Accessory pancreatic duct
  • Endocrine cell micronests
  • Intraductal papillary mucinous neoplasm
  • Pancreas divisum
  • Pancreatic polypeptide

 goto top of outline Abstract

The minor duodenal papilla, which is the orifice of the accessory, or dorsal, pancreatic duct/Santorini duct, mostly accompanied by pancreatic tissue, is situated about 2 cm ventroproximal to the major duodenal papilla. The patency of the terminal accessory pancreatic duct (APD) is recognized in about half or more of cases, and is related to the degree of fibrosis. The APD is lined with simple columnar epithelium and encircled by a smooth muscle layer. It is still controversial whether or not these muscle tissues comprise a sphincter muscle. Pancreatic tissue was found in about 80% of cases in the minor papilla. Among these cases, pancreatic tissue was continuous and/or closely related to the proper pancreas in about 40% of cases, and might have the same exocrine and endocrine morphologies/functions, suggesting that it is a portion of the dorsal pancreas and not an ectopic one. Endocrine cell micronests are frequently found in the ductal wall/surrounding area of the terminal APD, and predominantly consist of somatostatin- and/or pancreatic-polypeptide-containing cells. In cases of pancreas divisum, inadequate pancreatic juice drainage from the minor papilla might occur, resulting in dorsal pancreatitis. In the minor papilla, all ductal tumors may occur, such as an intraductal papillary mucinous neoplasms and invasive ductal carcinoma, but carcinoid tumors are rare.

Copyright © 2010 S. Karger AG, Basel


goto top of outline Introduction

The minor duodenal papilla, which is the orifice/duodenal termination of the accessory, or dorsal, pancreatic duct/Santorini duct, mostly accompanied by pancreatic tissue, is situated in the second portion of the duodenum, typically about 2 cm ventroproximal to the major duodenal papilla.

In the following, the histopathology of the minor duodenal papilla is described.

 

goto top of outline Duodenal Termination of the Accessory Pancreatic Duct

The terminal portion of the accessory pancreatic duct (APD) is the main component of the minor papilla and is nearly always present, but often regresses during development. The patency of the terminal APD is recognized in about half or more of cases [1,2,3] and is related to the degree of fibrosis [2]. The APD contains papillary fronds that are lined by simple columnar epithelium with some goblet cells [4] and encircled by a smooth muscle layer with surrounding growth (fig. 1). These muscle tissues have been the subject of controversy for more than a century regarding whether or not they form a sphincter muscle [2].

FIG01
Fig. 1. Minor duodenal papilla. The terminal portion of the APD is the main component of the minor papilla, accompanied by pancreatic tissue (arrows). MP = Muscularis propria. HE, ×10 (reproduced with permission from [5]).

One of the important roles of the APD is the additional drainage/outflow of pancreatic juice. In cases of pancreaticobiliary maljunction, in which the junction of the pancreatic and bile ducts is located outside the duodenal wall, pancreatic juice may flow freely into the extrahepatic bile duct and also the gallbladder, resulting in a higher risk of biliary tract carcinoma [6]. According to Kamisawa et al. [7], in these cases of high-level outflow of pancreatic juice into the duodenum through the APD, decreased pancreatic juice reflux into the bile duct may decrease the incidence of biliary tract carcinoma.

 

goto top of outline Pancreatic Tissue

Pancreatic tissue was found in about 80% of cases in the minor papilla [8]. Among these cases, the pancreatic tissue was continuous, without a gap, in the proper/original pancreas in about 20% of cases, and was also located within the muscularis propria of the duodenum, just adjacent to the proper/original site, in the other 20% of cases. Hence, the pancreatic tissue was continuous and/or closely related to the proper pancreas in about 40% of cases. The islets of Langerhans in the pancreatic tissue exhibited a round or oval shape with a few pancreatic polypeptide (PP) cells [8], similar to those of the dorsal pancreas [9,10]. Acinar cells showed positive immunoreactivity for anti-amylase, revealing functioning as in the exocrine pancreas [8]. Although the pancreatic tissue in the minor papilla was considered ectopic [11], based on the continuous tissue expansion to the proper site, and exhibited the same exocrine and endocrine morphologies/functions, it might be a portion of the dorsal pancreas.

 

goto top of outline Endocrine Cell Micronests

Endocrine cell micronests are frequently found in the minor papilla, especially in the ductal wall/surrounding area of the terminal APD (fig. 2). Their frequency was 52.2% in autopsy cases, being more frequent than those of the major papilla [12]. Endocrine cell micronests predominantly consist of somatostatin- and PP-containing cells, and most of the cells staining for somatostatin also contained PP [8,11]. In our previous study, PP cells were selectively found in the ventral pancreas and were stained positive for anti-serotonin, but not for anti-somatostatin [10]. Hence, endocrine cell micronests are a characteristic finding in the minor papilla.

FIG02
Fig. 2. Endocrine cell micronests (arrows) are present in the ductal wall/surrounding area of the terminal APD. Immunostaining for chromogranin A, ×200 (reproduced with permission from [5]).

The significance of PP cells in the minor papilla remains unknown, but might be related to movement of the APD, because the common bile duct ran into the ventral pancreas, which is abundant in PP cells.

 

goto top of outline Pancreas Divisum

Pancreas divisum is a congenital anomaly in which the dorsal and ventral pancreatic ducts do not unite or communicate, and separately drain into the two duodenal papillae. Under this condition, pancreatic juice from the dominant dorsal moiety flows out only through the minor papilla, in which the outlet is notably small in most cases [6]. Subsequently, inadequate pancreatic juice drainage from the minor papilla may occur, called dorsal pancreatitis, a kind of chronic obstructive pancreatitis, which shows inter- and intralobular fibrosis with atrophy or disappearance of the acinar cells/lobuli.

 

goto top of outline Tumor of Minor Duodenal Papilla

In the minor duodenal papilla, all ductal tumors may occur, such as intraductal papillary mucinous neoplasms and invasive ductal carcinomas, but carcinoid tumors are less frequent in the minor than in the major papilla [12].


 goto top of outline References
  1. Kamisawa T: Clinical significance of the minor duodenal papilla and accessory pancreatic duct. J Gastroenterol 2004;39:605–615.
  2. Stimec B, Alempijevic T, Micev M, Milicevic M, Ille T, Kovacevic N, Bulajic M: Relationship between papillary fibrosis and patency of the accessory pancreatic duct. Ann Anat 2005;187:99–103.
  3. Komatsu K: Pancreatographical and histopathological study of dilatation of the pancreatic ducts – with special references to cystic dilatations (in Japanese). Juntendo Med J 1973;19:250–269.
  4. Friersonk HF Jr: The gross anatomy and histology of the gallbladder, extrahepatic ducts, Vaterian system, and minor papilla. Am J Surg Pathol 1989:13:146–162.
  5. Kamisawa T (ed): Major and Minor Duodenal Papilla. Tokyo, Arc Medium, 2009.
  6. Suda K, Nobukawa B, Suzuki F, Fujii H, Matsumoto M, Matsumoto Y, Miyano T: Anomalous lesions of the pancreatic head and Vaterian system, related to their structures; in Suda K (ed): Pancreas – Pathological Practice and Research. Basel, Karger 2007, pp 12–24.
  7. Kamisawa T, Tu Y, Egawa N, Tsuruta K, Okamoto A, Matsukawa M: Pancreas divisum in pancreaticobiliary maljunction. Hepatogastroenterology 2008;55:249–253.
  8. Suda K, Mogaki M: Histopathological and immuno-histochemical studies on the minor duodenal papilla (in Japanese). J Jpn Pancreat Soc 1990;4:511–517.
  9. Suda K, Mizuguchi K, Hoshino A: Differences of the ventral and dorsal anlagen of pancreas after fusion. Acta Pathol Jpn 1981;31:583–589.
  10. Suda K, Yuminamochi T, Ishii Y, Nakazawa K, Kawaoi A: Distribution of endocrine cells based on difference of the pancreatic anlage (in Japanese). Jpn J Clin Pathol 1987;35:809–812.
  11. Chatelain D, Vibert E, Yzet T, Geslin G, Bartoli E, Manaouil D, Delcenserie R, Brevet M, Dupas J-L, Regimbeau J-M: Groove pancreatitis and pancreatic heterotopia in the minor duodenal papilla. Pancreas 2005;30:e92–e95.
  12. Noda Y, Watanabe H, Iwafuchi M, Furuta K, Ishihara N, Satoh M, Ajioka Y: Carcinoids and endocrine cell micronests of the minor and major duodenal papillae. Their incidence and characteristics. Cancer 1992;70:1825–1833.

 goto top of outline Author Contacts

Koichi Suda, MD
Department of Pathology, Tokyo-Nishi Tokushukai Hospital
3-1-1 Matsubara-cho, Akishima-shi
Tokyo 196-0003 (Japan)
Tel. +81 42 500 4433, Fax +81 42 500 6632, E-Mail koichi.suda@tokushukai.jp


 goto top of outline Article Information

Published online: June 10, 2010
Number of Print Pages : 3
Number of Figures : 2, Number of Tables : 0, Number of References : 12


 goto top of outline Publication Details

Digestive Surgery

Vol. 27, No. 2, Year 2010 (Cover Date: June 2010)

Journal Editor: Büchler M.W. (Heidelberg), Neoptolemos J.P. (Liverpool)
ISSN: 0253-4886 (Print), eISSN: 1421-9883 (Online)

For additional information: http://www.karger.com/DSU


Copyright / Drug Dosage / Disclaimer

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

Abstract

The minor duodenal papilla, which is the orifice of the accessory, or dorsal, pancreatic duct/Santorini duct, mostly accompanied by pancreatic tissue, is situated about 2 cm ventroproximal to the major duodenal papilla. The patency of the terminal accessory pancreatic duct (APD) is recognized in about half or more of cases, and is related to the degree of fibrosis. The APD is lined with simple columnar epithelium and encircled by a smooth muscle layer. It is still controversial whether or not these muscle tissues comprise a sphincter muscle. Pancreatic tissue was found in about 80% of cases in the minor papilla. Among these cases, pancreatic tissue was continuous and/or closely related to the proper pancreas in about 40% of cases, and might have the same exocrine and endocrine morphologies/functions, suggesting that it is a portion of the dorsal pancreas and not an ectopic one. Endocrine cell micronests are frequently found in the ductal wall/surrounding area of the terminal APD, and predominantly consist of somatostatin- and/or pancreatic-polypeptide-containing cells. In cases of pancreas divisum, inadequate pancreatic juice drainage from the minor papilla might occur, resulting in dorsal pancreatitis. In the minor papilla, all ductal tumors may occur, such as an intraductal papillary mucinous neoplasms and invasive ductal carcinoma, but carcinoid tumors are rare.



 goto top of outline Author Contacts

Koichi Suda, MD
Department of Pathology, Tokyo-Nishi Tokushukai Hospital
3-1-1 Matsubara-cho, Akishima-shi
Tokyo 196-0003 (Japan)
Tel. +81 42 500 4433, Fax +81 42 500 6632, E-Mail koichi.suda@tokushukai.jp


 goto top of outline Article Information

Published online: June 10, 2010
Number of Print Pages : 3
Number of Figures : 2, Number of Tables : 0, Number of References : 12


 goto top of outline Publication Details

Digestive Surgery

Vol. 27, No. 2, Year 2010 (Cover Date: June 2010)

Journal Editor: Büchler M.W. (Heidelberg), Neoptolemos J.P. (Liverpool)
ISSN: 0253-4886 (Print), eISSN: 1421-9883 (Online)

For additional information: http://www.karger.com/DSU


Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

References

  1. Kamisawa T: Clinical significance of the minor duodenal papilla and accessory pancreatic duct. J Gastroenterol 2004;39:605–615.
  2. Stimec B, Alempijevic T, Micev M, Milicevic M, Ille T, Kovacevic N, Bulajic M: Relationship between papillary fibrosis and patency of the accessory pancreatic duct. Ann Anat 2005;187:99–103.
  3. Komatsu K: Pancreatographical and histopathological study of dilatation of the pancreatic ducts – with special references to cystic dilatations (in Japanese). Juntendo Med J 1973;19:250–269.
  4. Friersonk HF Jr: The gross anatomy and histology of the gallbladder, extrahepatic ducts, Vaterian system, and minor papilla. Am J Surg Pathol 1989:13:146–162.
  5. Kamisawa T (ed): Major and Minor Duodenal Papilla. Tokyo, Arc Medium, 2009.
  6. Suda K, Nobukawa B, Suzuki F, Fujii H, Matsumoto M, Matsumoto Y, Miyano T: Anomalous lesions of the pancreatic head and Vaterian system, related to their structures; in Suda K (ed): Pancreas – Pathological Practice and Research. Basel, Karger 2007, pp 12–24.
  7. Kamisawa T, Tu Y, Egawa N, Tsuruta K, Okamoto A, Matsukawa M: Pancreas divisum in pancreaticobiliary maljunction. Hepatogastroenterology 2008;55:249–253.
  8. Suda K, Mogaki M: Histopathological and immuno-histochemical studies on the minor duodenal papilla (in Japanese). J Jpn Pancreat Soc 1990;4:511–517.
  9. Suda K, Mizuguchi K, Hoshino A: Differences of the ventral and dorsal anlagen of pancreas after fusion. Acta Pathol Jpn 1981;31:583–589.
  10. Suda K, Yuminamochi T, Ishii Y, Nakazawa K, Kawaoi A: Distribution of endocrine cells based on difference of the pancreatic anlage (in Japanese). Jpn J Clin Pathol 1987;35:809–812.
  11. Chatelain D, Vibert E, Yzet T, Geslin G, Bartoli E, Manaouil D, Delcenserie R, Brevet M, Dupas J-L, Regimbeau J-M: Groove pancreatitis and pancreatic heterotopia in the minor duodenal papilla. Pancreas 2005;30:e92–e95.
  12. Noda Y, Watanabe H, Iwafuchi M, Furuta K, Ishihara N, Satoh M, Ajioka Y: Carcinoids and endocrine cell micronests of the minor and major duodenal papillae. Their incidence and characteristics. Cancer 1992;70:1825–1833.