Adenocarcinoma of the minor duodenal papilla with intraepithelial spread to the pancreatic duct

It is extremely rare to encounter tumors arising exclusively in the minor duodenal papilla. We report a 60-year-old male patient with a polypoid type of adenocarcinoma of the minor papilla. Preoperative examinations, including computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP), suggested pancreas divisum and showed a series of stones in the dorsal pancreatic duct. The patient underwent subtotal stomach-preserving pancreaticoduodenectomy (SSpPD). On histology, an adenocarcinoma was located in the minor papilla, which was limited to the mucosa, without invasion of the duodenum, sphincter muscles of the minor papilla, or the underlying pancreas. The carcinoma cells, together with dysplastic and hyperplastic epithelium of the pancreatic duct, extended peripherally within the pancreatic duct. No cystic dilatation of the pancreatic duct was observed. The ventral pancreatic duct was short and narrow; there was evidence of chronic pancreatitis in the dorsal pancreas, whereas the ventral pancreas was almost normal, suggesting the existence of pancreas divisum. Although it is well known that adenocarcinoma of the duodenal papilla is sometimes accompanied by intraepithelial spread in the pancreatic duct, an adenocarcinoma arising in the minor papilla in this case with pancreas divisum was more extended than our thoughts.     

Pancreatographic investigation of the pancreatic duct system

Background Embryologically, the pancreatic duct system develops by the fusion between the dorsal and ventral pancreatic bud ducts. It has been suggested that the proximal part of the main dorsal pancreatic duct partially regresses to form the accessory pancreatic duct (APD). Aim of this study was to clarify the anatomy of the pancreatic duct system of the head of the pancreas and investigate the embryology of the normal pancreatic duct system. Methods We reviewed endoscopic retrograde pancreatography of normal pancreatic heads (n = 256) and pancreas divisum (n = 36), focusing on long inferior branches arising from the APD and the main pancreatic duct (MPD). The accessory pancreatograms were divided into two patterns of course and shape, the long type (171 cases) and the short type (85 cases) according to the length of the MPD from the orifice to the junction with the APD. The long-type APD formed a straight line and joined the MPD at the neck portion of the pancreas. The short-type APD joined the MPD near its first inferior branch. Results The shape of the long-type APD was quite similar to that of the dorsal pancreatic duct of pancreas divisum. The short-type APD was less likely to have a long inferior branch arising from the APD. The length of the APD from the orifice to the first long inferior branch was similar in the long-type APD (19.4 ± 4.0 mm) and in the short-type APD (18.8 ± 4.2 mm). The first long inferior branch from the long-type APD passed though the MPD near the origin of the inferior branch from the MPD, whereas the short-type APD joined the MPD near its inferior branch. Conclusions There are two types of APD. The long-type APD was quite similar to the shape of the dorsal pancreatic duct of pancreas divisum, and seems to represent a continuation of the main duct of the dorsal pancreatic bud. The short-type APD was less likely to have a long inferior branch, and seems to be formed by the most proximal part of the main duct of the dorsal pancreatic bud and its long inferior branch.     

Pancreatographic investigation of pancreatic duct system and pancreaticobiliary malformation

To clarify the anatomy of the pancreatic duct system and to investigate its embryology, we reviewed 256 pancreatograms with normal pancreatic head, 81 with pancreas divisum and 74 with pancreaticobiliary maljunction. Accessory pancreatograms were divided into two patterns. The long-type accessory pancreatic duct forms a straight line and joins the main pancreatic duct at the neck portion of the pancreas. The short-type accessory pancreatic duct joins the main pancreatic duct near its first inferior branch. The short-type accessory pancreatic duct is less likely to have a long inferior branch arising from the accessory pancreatic duct. The length of the accessory pancreatic duct from the orifice to the first long inferior branch was similar in the short- and long-type accessory pancreatic ducts. The first long inferior branch from the long-type accessory pancreatic duct passes though the main pancreatic duct near the origin of the inferior branch from the main pancreatic duct. Immunohistochemically, in the short-type accessory pancreatic duct, the main pancreatic duct between the junction with the short-type accessory pancreatic duct and the neck portion was located in the ventral pancreas. The long-type accessory pancreatic duct represents a continuation of the main duct of the dorsal pancreatic bud. The short-type accessory pancreatic duct is probably formed by the proximal main duct of the dorsal pancreatic bud and its long inferior branch.     

Pancreas divisum inversus

Pancreatic duct variations are usually diagnosed incidentally, in particular when using magnetic resonance cholangiopancreatography (MRCP), the most accurate imaging modality for depicting the pancreatic ductal system. However, the frequency and the embryologic development of pancreatic variants have not been well investigated. The purpose of this prospective study was to investigate the frequency of pancreatic ductal variants, providing potential explanations of their embryologic basis. The pancreatic ductal anatomies of 202 patients with mean ± standard deviation (SD) age of 54 ± 27 years, 56% females, who underwent MRCP for different indications between April 2018 and March 2019, were prospectively collected. Normal pancreatic ductal variants were identified in 196 cases (97%), and variants of pancreas divisum in six cases (3%). In the type C variant of the normal pancreatic anatomy, found in 3% of the cases, the dorsal duct was joined to the ventral duct while the accessory duct did not communicate with the dorsal duct. Unlike the classic type C variant, in our cases, the accessory pancreatic duct (APD) was long (mean ± SD of 58 ± 8.5 mm) and originated in the lower portion of the pancreatic head, caudally to the duct of Wirsung. This was a new subtype of the type C variant or a new variant, which could be called “pancreas divisum inversus”; the APD could be called the isolated duct of Santorini. Reporting this new variant could increase knowledge regarding the pancreatic anatomy in order to avoid misdiagnosis and to help in better understanding pancreatic diseases and their relative treatment. Clin. Anat., 33:646–652, 2020. © 2019 Wiley Periodicals, Inc.     

Invasive ductal carcinoma of the pancreas tail with noninvasive growth through the nondilated main pancreatic duct and macroscopically cystic invasive carcinomatous glands

Noninvasive growth forming macroscopically dilated cystic pancreatic ducts is a fundamental feature of intraductal papillary mucinous neoplasm (IPMN), from which invasive carcinomas can arise. However, some invasive ductal carcinomas of the pancreas also show a macroscopically cystic feature. We experienced 2 cases of invasive ductal carcinoma of the pancreas tail with noninvasive growth through the main pancreatic duct without dilation at the body side, and with collection of macroscopically cystic carcinomatous glands infiltrating at the spleen side, which resembled some IPMNs and/or IPMN-derived invasive carcinomas. These cases were different from IPMN in that they lacked macroscopic dilatation of the pancreatic ducts, and the macroscopically dilated cystic carcinomatous glands were invasive but not intraductal. The intraductal component of the carcinomas showed papillary growth of neoplastic epithelia with atypia consistent with PanIN-3. Both intraductal and invasive components predominantly showed gastric mucin phenotype (MUC5AC+, MUC6 focally +, MUC2− or MUC2+ in scattered small number of cells). Recognition of these pancreatic carcinoma cases is important in the following 2 points: (1) The presence of such cases should always be kept in mind as differential diagnosis of IPMN or IPMN-derived invasive carcinoma in imaging and pathologic diagnoses. (2) The histogenesis of these cases might be placed in the intermediate between 2 major histogenetic pathways of pancreatic carcinoma, that is, one from microscopic precursors called PanIN and the other from macroscopic precursors of IPMN. These cases can be regarded as invasive carcinomas derived from semimacroscopic extension of the intraductal lesion of the main pancreatic duct.     

儿童胰腺实性假乳头状瘤多排螺旋CT表现

目的:探讨儿童胰腺实性假乳头状瘤（SPTP）的多排螺旋CT（MDCT）表现。 方法:回顾性分析经手术病理证实为SPTP的10例患儿临床及MDCT资料,分析总结其特征表现。 结果:10例患儿均为女性,SPTP均为单发病灶,位于胰腺头颈部3例,胰腺体尾部7例。肿瘤最大径为2.5~13.8 cm,平均值为5.94 cm。8例呈类圆形,2例呈分叶状。10例均边界清晰,8例有完整包膜。平扫1例肿瘤呈均匀低密度,增强无明显强化;其余9例呈囊实性,8例以实性为主,1例囊实性比例相当,其中1例可见包膜下弧形钙化,实性成分动脉期呈轻度强化,强化程度低于正常胰腺组织,门脉期呈渐进性不均匀强化,囊性成分无强化。1例肿瘤出现肝内胆管和主胰管轻度扩张,1例出现主胰管轻度扩张。所有肿瘤均未见肝脏及淋巴结转移。 结论:儿童SPTP好发于女性,其CT表现具有一定的特征性,对诊断和鉴别诊断具有一定意义。     

The anatomical study on the rat pancreas and its ducts with emphasis on the surgical approach.

It was intended to present information about the anatomy of the pancreas and especially to emphasize the variation of pancreatic ducts in the rat, which may guide researchers in experimental studies. In 27 adult rats, latex dye was introduced into the biliopancreatic duct, portal vein and arteries. The pancreas with the neighboring structures was studied with the aid of the dissection microscope and measurements were by means of micrometric ocular. The pancreas was divided into three parts i.e. the biliary, duodenal and gastrosplenic portions. The biliopancreatic and pancreatic ducts as well as biliary and duodenal portions of the pancreas could be seen ventrally with a minor procedure such as pulling the duodenum caudally, and additionally the entire pancreas and its ducts could also be reached dorsally since the stomach was turned cranially with the duodenum. The biliopancreatic duct diameter and length of the ducts were 1.01+/-0.03 and 28.86+/-0.59 mm, respectively. The anterior pancreatic duct originated from the biliopancreatic duct on different sides, 17.96+/-0.75mm away from the duodenal papilla. The anterior pancreatic duct drained the gastrosplenic portion of the rat pancreas and this duct, via the duodenal duct, partially collected secretion of the duodenal portion at a ratio of 74.07%. The posterior pancreatic duct opened to the biliopancreatic duct and its distance from papilla duodeni was changed from 0 to 8 mm. When the biliopancreatic duct is ligated at the level of the duodenal opening, the posterior pancreatic duct or a small duct from duodenal portion should be taken into consideration because these ducts opened to biliopancreatic duct at the level of papilla duodeni at a ratio of 37.04%. In conclusion, the duct system of pancreas had a great variation and therefore the success rate of the surgery could be increased when surgeons have more knowledge on variations of the duct system in this region.     

Anatomical features of the minor duodenal papilla in pancreas divisum

Background Clinical expression of pancreas divisum is often explained as a consequence of relative or true stenosis of the minor papilla with dorsal duct obstruction. This anatomo-functional study of the minor papilla in pancreas divisum has included its topographical, functional and structural features.Materials and methods The study was carried out on 37 human autopsy specimens of duodenopancreas, which underwent pancreatography, manometrically controlled perfusion and light microscopy.Results One pancreas divisum was detected in the study group. In this case, the distances between the minor and the major papilla was 24.0 mm, and between the minor papilla and the superior duodenal flexure 27.4 mm. The minor papilla was patent when perfused under pressure of 10 mmHg, and its light microscopy revealed regular global histological organization with only light fibrosis and no cellular atypia.Conclusions The structure and position of the minor papilla in pancreas divisum did not significantly differ from the ones in fused pancreases.     

Unusual fusion between ventral and dorsal primordia causes anomalous pancreaticobiliary junction

Anomalous pancreaticobiliary junction (APBJ) is a congenital anomaly in which the pancreatic duct joins the common bile duct proximal to the sphincter of Oddi. Anatomical and immunohistochemical examination of the pancreas with APBJ has rarely been performed. A 72-year-old woman with gallbladder cancer and APBJ died of respiratory failure. Macroscopic features of the pancreas were examined in detail. Immunohistochemistry using anti-pancreatic polypeptide (anti-PP) antibody was done to discriminate ventral and dorsal pancreas. Macroscopically the inferior part of the head of the pancreas was smaller than normal. The posterior surface of the head was obliquely grooved. Part of the pancreatic head protruded into the posterior side of the pancreatic head. A PP-rich region was located in the superioposterior position of the pancreas head. Considering the relationship between the ventral and dorsal pancreas, it was inferred that the ventral primordium could obliquely fuse with the dorsal primordium during embryological development. As a result, APBJ occurs through an abnormal fusion between ventral and dorsal primordia.     

Pancreatic hemi-agenesis in MEN1: A clinical report

We first describe a patient with multiple endocrine neoplasia type 1 (MEN1) and dorsal pancreatic hemi-agenesis. Previously, pancreas divisum has been reported in MEN1.Recent data in mice have elucidated the molecular mechanisms of pancreatic endoderm specification. Disinhibition of hedgehog signaling appears to be important in how Gata4 and Gata6 variants cause pancreatic agenesis. Disinhibition of hedgehog signaling has also been observed in Men1 knockout pancreatic islets.Although we cannot exclude a spurious association between dorsal pancreatic hemi-agenesis and MEN1 in our patient, we argue that developmental abnormalities of the pancreas may have to be considered as possibly related to the MEN1 phenotype.     

Intraductal Pancreatic Neuroendocrine Tumor

Intraductal lesions of the pancreas are usually due to intraductal papillary mucinous neoplasms and the less common intraductal tubular adenoma. Cases of acinar cell carcinoma within intraductal location have also been encountered recently. Pancreatic neuroendocrine tumors are rarely encountered within the main pancreatic duct. A 74-year-old male presented with non-specific abdominal symptoms and was found to have an obstructive lesion in the main pancreatic duct with associated chronic pancreatitis. A distal pancreatectomy was performed which revealed a solid and cystic tumor measuring 6 × 3 × 2 cm situated wholly within the main pancreatic duct. It formed an obstructing intraluminal polypoid lesion that resulted in surrounding chronic pancreatitis. Microscopic evaluation of the mass showed it to be a well-differentiated pancreatic neuroendocrine tumor with entrapped, non-malignant tubules. Intraductal pancreatic neuroendocrine tumors may occur in two settings. Firstly, and more commonly, there is a parenchymal-based tumor that then encroaches on and pushes into the main pancreatic duct. The less common scenario is of a primary intraductal location without a pancreatic parenchymal lesion. While an intraductal location of a pancreatic neuroendocrine tumor is rare, it should be borne in mind when confronted by an intraductal lesion in the pancreas.     

Primary adenocarcinoma of the minor duodenal papilla

A 70-year-old man was admitted to our institution due to aggravation of blood-sugar level control and because an abdominal CT showed dilatation of the main pancreatic duct. Upper gastrointestinal endoscopy revealed a flat elevated tumor with central ulceration in the second portion of the duodenum. Subsequent duodenoscopy for a more detailed examination showed that the tumor had originated in the minor duodenal papilla. A biopsy specimen showed moderately differentiated adenocarcinoma. Endoscopic retrograde pancreatography via the major duodenal papilla revealed a slightly dilated main pancreatic duct and obstruction of the accessory pancreatic duct. Endoscopic ultrasonography showed a hypoechoic mass in the minor duodenal papilla with retention of the muscularis propria of the duodenum. These findings suggest that the tumor existed only to a limited extent in the minor duodenal papilla, and that the tumor did not infiltrate into the pancreas. For treatment, pylorus-preserving pancreatoduodenectomy was performed, and histological findings revealed a well-differentiated adenocarcinoma that originated in the minor duodenal papilla. Primary adenocarcinoma of the minor duodenal papilla is extremely rare. Our case is the first report of primary adenocarcinoma of the minor duodenal papilla at an early stage with no infiltration into muscularis propria of the duodenum and pancreas.     

Anomalous pancreatico-biliary ductal union with cystic dilatation of the bile duct

We report, in an adult, an asymptomatic association between cystic dilatation of the bile duct (type IV A in Todani’s classification) and anomalous pancreatico-biliary ductal union (APBD) with stones in a long common channel. In APBD, the connection between the common bile duct and the main pancreatic duct is located outside the duodenal wall and is therefore not under the influence of the sphincter of Boyden. An abnormally long common channel is in excess of 15 mm. Two types of convergence anomalies are defined according to whether the bile duct opens into the main pancreatic duct (BP) or the main pancreatic duct into the bile duct (PB). In APBD, there is probably a reverse pressure gradient between the bile and pancreatic ducts, with regurgitation of pancreatic juice into the bile duct, repeated attacks of cholangitis, stenosis and cystic dilatation. A long common channel is associated with a higher incidence of carcinoma of the gall bladder or the bile duct.     

Pancreatic abscess associated with pancreas divisum

Pancreas divisum has been implicated as a cause of pancreatitis. Pseudocyst development in association with chronic pancreatitis has also been observed in a few patients with this anomaly. The association of pancreatic abscess with pancreas divisum has not been observed previously. The case herein reported illustrates a coincidental finding of pancreas divisum in a patient who presented with a pancreatic abscess.     

A case of minute intraductal papillary mucinous tumor of the pancreas presenting with recurrent acute pancreatitis

Intraductal papillary mucinous tumor (IPMT) of the pancreas, a lesion consisting of mucin-producing cells with neoplastic potential, is characterized by duct ectasia, mucin hypersecretion, often extensive papillary intraductal growth, varying degrees of cytologic atypia, and relatively indolent growth. The clinical presentation of IPMT of the pancreas is characterized by chronic or recurrent attacks of abdominal discomfort often in association with low level pancreatic enzyme elevations. Less commonly these lesions may be detected as asymptomatic radiographic abnormalities. Interestingly, a case of a minute IPMT (2 mm in height and 7 mm in length, adenoma) in the main pancreatic duct presenting with acute pancreatitis in a 55 year-old man has been reported in the Japanese literature. Recently, we also experienced a case of a minute IPMT in a branch pancreatic duct causing repeated bouts of acute pancreatitis in a 75 year-old man. A filling defect at the neck of the main pancreatic duct seen on an endoscopic retrograde pancreatogram performed after recovery of the second attack of acute pancreatitis led the patient to undergo an exploratory laparotomy. After a near-total pancreatectomy was carried out, a minute (3 x 7 mm) IPMT of borderline malignancy was discovered in a branch duct at the head portion near the pancreatic neck without any lesions in the main pancreatic duct. Surprisingly, despite the resective surgery the patient died of carcinomatosis 8.5 months after the operation. We herein report a case of a minute but aggressive IPMT of the pancreas with a review of the literature.     

The relationship of anatomic variation of pancreatic ductal system and pancreaticobiliary diseases

The aims of this study were to identify the morphological diversities and anatomical variations of pancreatic ductal system and to define the relationships between pancreatic ductal systems, pancreaticobiliary diseases, and procedure- related complications, including post-ERCP pancreatitis. This study included 582 patients in whom both pancreatic duct (PD) and common bile duct were clearly visible by ERCP. PD systems were categorized into four types according to the relationship between common bile duct and PD. In types A and B, Wirsung duct formed the main PD. In type C, Wirsung duct did not form the main PD. If PD system did not fall into any of these three types, it was categorized as type D. The distribution of types among pancreatic ducts examined was as follows: type A: 491 cases (84.4%), type B: 56 cases (9.6%), type C: 20 cases (3.4%), and type D: 15 cases (2.6%). The anomalous anatomic variations of PD systems were divided into migration, fusion, and duplication anomalies. PD anomalies were noted in 51 patients, of which 19 (3.3%) were fusion anomalies (12 complete pancreas divisum, 7 incomplete pancreas divisum), and 32 (5.5%) were duplication anomalies (5 number variations, 27 form variations). No significant relationships between various PD morphologies and pancreaticobiliary diseases were found. However, post- ERCP hyperamylasemia was more frequently found in types C (41.7%), D (50%) and A (19.8%) than in type B (9.4%). In summary, whether Wirsung duct forms the main PD and the presence or absence of the opening of the Santorini duct are both important factors in determining the development of pancreatitis and hyperamylasemia after ERCP.     

Duct‐obstructive pancreatitis with granulocytic epithelial lesion in a patient with ulcerative colitis: An atypical manifestation of type 2 autoimmune pancreatitis?

Type 2 autoimmune pancreatitis (AIP) typically presents with diffuse or focal enlargement of the pancreas; however, its diverse clinical presentation has not yet been clarified. We herein described a 46‐year‐old man with a 1‐month history of ulcerative colitis who presented with imaging features of a mass‐like lesion in the pancreatic body with upstream duct dilatation and serum CA19‐9 elevation. He underwent laparoscopic distal pancreatectomy with splenectomy for suspected malignancy. Histologically, the area radiologically suspected to be duct dilatation consisted of necrotic tissue, in which the disrupted main pancreatic duct was involved. The area radiologically suspected to be the mass lesion showed features of pancreatitis without discrete mass. In addition, several ducts showed neutrophilic duct injury similar to granulocytic epithelial lesions observed in type 2 AIP. Immunohistochemistry revealed the aberrant expression of IL‐8 in the pancreatic ductules and infiltrating CD3‐positive T‐lymphocytes, findings recently identified in type 2 AIP. The present case is not typical for either type 2 AIP or other known conditions, but extreme examples of type 2 AIP may present with ductal obstruction because of severe neutrophilic duct injury. IL‐8 immunostaining may also assist in establishing a diagnosis of type 2 AIP with an atypical presentation.