Biomedical subjects

Kouji Tsuruta

Publications and source records attributed to Kouji Tsuruta.

35 records · Page 2Linked to original sources

PubMed2004

Pathologic changes in the non-carcinomatous epithelium of the gallbladder in patients with a relatively long common channel.

BACKGROUND: Except for pancreaticobiliary maljunction, the relationship between a relatively long common channel and gallbladder carcinoma is unknown. METHODS: For purposes of this study, a high confluence of pancreaticobiliary ducts was defined as a common channel that is 6 mm or greater in length, together with occlusion of the communication between the pancreatic and bile ducts during sphincter contraction. Pancreaticobiliary maljunction and high confluence of the pancreaticobiliary ducts were detected in 69 (2.1%) and 54 (1.6%), respectively, of 3300 consecutive patients who underwent ERCP. Proliferation activity and genetic alteration were examined in the non-carcinomatous epithelium of the gallbladder in patients with these two radiographic findings at ERCP. RESULTS: The Ki-67 labeling index in the epithelium in cases of a high confluence of the pancreaticobiliary ducts and pancreaticobiliary maljunction without biliary dilatation was significantly greater than that in cases of gallbladder carcinoma without these anomalies (p < 0.01). Overexpression of p53 and K-ras mutations were detected in, respectively, 22.2% and 27.8% of cases of a high confluence of pancreaticobiliary ducts. CONCLUSIONS: A relatively long common channel may be an important risk factor for the development of gallbladder carcinoma. Vigilance for the development of gallbladder carcinoma is indicated in patients with a relatively long common channel, in addition to those with pancreaticobiliary maljunction.

Bile Ducts↗

PubMed2003

A new clinicopathological entity of IgG4-related autoimmune disease.

BACKGROUND: Autoimmune pancreatitis (AIP) is occasionally associated with other autoimmune diseases. METHODS: To investigate the pathophysiology of AIP, we immunohistochemically examined the pancreas and other organs in eight patients with AIP, and in controls, using anti-CD4-T and CD8-T cell subsets, as well as IgG4 antibodies. RESULTS: In AIP patients, severe or moderate infiltration of IgG4-positive plasma cells associated with CD4- or CD8-positive T lymphocytes was detected in the peripancreatic tissue (6/6), bile duct (8/8), gallbladder (8/8), portal area of the liver (3/3), gastric mucosa (5/7), colonic mucosa (2/2), salivary glands (1/2), lymph nodes (6/6), and bone marrow (2/2), as well as in the pancreas (8/8). There were few IgG4-positive plasma cells at the same sites in controls. CONCLUSIONS: These results suggest that AIP is not simply pancreatitis but that it is a pancreatic lesion involved in IgG4-related systemic disease with extensive organ involvement. We propose a new clinicopathological entity, of a systemic IgG4-related autoimmune disease in which AIP and its associated diseases might be involved. Autoimmune pancreatitis (AIP) is occasionally associated with other autoimmune diseases.

Aged↗

PubMed2003

Pancreatic endocrine and exocrine function and salivary gland function in autoimmune pancreatitis before and after steroid therapy.

INTRODUCTION: Autoimmune pancreatitis (AIP) is a distinct clinical entity in which an autoimmune mechanism may be involved in pathogenesis. AIM: To investigate salivary gland function in addition to pancreatic endocrine and exocrine function in patients with AIP, and to determine changes occurring after steroid therapy. METHODOLOGY: Fasting serum glucose levels, oral glucose tolerance tests or glycosylated hemoglobin values were examined in 19 patients with AIP. N-benzoyl-L-tyrosyl-p-aminobenzoic acid excretion test, sialochemistry and parotid gland scintigraphy were performed in 8 patients. RESULTS: Eight patients had evidence of DM. Steroid therapy subsequently improved insulin secretion and glycemic control in 3 of 5 patients treated. Pancreatic exocrine function was reduced in 88% of patients. Impaired pancreatic exocrine function improved after steroid therapy in 3 of 6 patients treated. The 3 patients also showed treatment-related improvement in endocrine function. Concentration of beta2-microglobulin in saliva was significantly raised in patients with AIP compared with controls (P < 0.05). Ratio of cumulative peak count to injected radionuclide and washout ratio in parotid scintigraphy in patients with AIP was significantly lower than those of controls (P < 0.01). Salivary gland dysfunction improved after steroid therapy in all 5 patients treated. CONCLUSIONS: Pancreatic endocrine and exocrine and salivary gland function were frequently impaired in patients with AIP, and steroid therapy was occasionally effective for these dysfunctions.

Adult↗

PubMed2003

Clinical difficulties in the differentiation of autoimmune pancreatitis and pancreatic carcinoma.

OBJECTIVES: Autoimmune pancreatitis (AIP) is a newly described entity with characteristic clinical, histologic, and morphologic changes, in which autoimmune mechanisms are involved in pathogenesis. However, difficulties can arise in the differentiation of AIP from pancreatic carcinoma. The aims of this study were to clarify clinical and radiologic features of AIP to elucidate areas of diagnostic confusion. METHODS: Clinical, serologic, and radiologic findings were evaluated in 17 patients with AIP. RESULTS: All 17 patients were initially suspected to have pancreatic carcinoma. The patients were predominantly elderly men who frequently presented with jaundice but without features of acute pancreatitis. Elevation of serum gamma-globulin and IgG along with the presence of autoantibodies were usually evident, whereas serum tumor markers were elevated in 54% of cases. Stenosis of the bile duct was detected in 94% of cases. Diffuse enlargement of the pancreas and irregular narrowing of the main pancreatic duct were radiologically characteristic; however, segmental swelling and narrowing were detected in seven and two patients, respectively. In segmental cases, neither atrophy of the distal pancreas nor marked upstream dilation of the distal main pancreatic duct was observed. Angiographic abnormalities occurred in 54% of cases. Serologic and radiologic abnormalities showed considerable improvement with steroid therapy. CONCLUSIONS: Frequent stenosis of the bile duct, elevation of serum tumor markers, segmental pancreatic enlargement or narrowing of the main pancreatic duct, and angiographic abnormalities can cause confusion in the differential diagnosis of AIP and pancreatic carcinoma.

Adult↗

PubMed2002

Ductal and acinar differentiation in pancreatic endocrine tumors.

Rare pancreatic endocrine tumors consisting of both exocrine and endocrine components have been reported sporadically. We investigated the ductal and acinar differentiation in pancreatic endocrine tumors. In immunohistochemical studies of 28 pancreatic endocrine tumors, staining with anti-carcinoembryonic antigen (CEA) or CA19-9 antibody indicated ductal differentiation, while staining with anti-amylase or anti-trypsin antibody indicated acinar differentiation. K-ras gene mutations and p53 gene alterations also were studied. Ten tumors were immunoreactive for CEA or CA19-9. Five tumors diffusely immunoreactive for CEA or CA19-9, in addition to endocrine markers, were diagnosed as duct-endocrine cell tumors of the pancreas. Two tumors diffusely immunoreactive for CEA or CA19-9 and also for pancreaticogut hormones as well as endocrine markers were diagnosed as duct-acinarendocrine cell tumors. These tumors showed uniform histologic features and synchronous ductal, acinar, and endocrine differentiation, distinct from the coexisting different cellular populations seen in collision tumors. All tumors were malignant. These duct-endocrine cell tumors or duct-acinar- endocrine cell tumors of the pancreas may be derived from a stem cell that retains the capability of expressing either an exocrine or endocrine phenotype. Only one K-ras gene mutation and no p53 gene alterations were detected in these tumors, which suggests that they constitute an entity with a different origin than ductal carcinomas.

Adult↗

PubMed2002

Clinical significance of a long common channel.

BACKGROUND/AIM: It was reported that in only 19 (11%) of 173 patients was the common channel at the junction of the pancreatic and bile ducts found to be 6 mm or longer. Pancreaticobiliary maljunction (PBM) is defined as an anomaly with a markedly long common channel with the junction located outside the duodenal wall, so the action of the sphincter of Oddi does not functionally affect the junction. We defined high confluence of pancreaticobiliary ducts (HCPBD) as a length of the common channel > or = 6 mm, in which the communication between the pancreatic and bile ducts was occluded when the sphincter was contracted. This study aims at investigating the clinical significance of HCPBD. METHODS: 2,980 consecutive cases with an adequate endoscopic retrograde cholangiopancreatography were reviewed. PBM and HCPBD were diagnosed according to the above definitions. PBM was divided into two groups: with or without biliary dilatation. RESULTS: PBM and HCPBD were detected in 63 (2.1%) and 50 (1.7%) cases, respectively. Biliary dilatation was detected in 30 cases having PBM. The incidences of gallbladder carcinoma associated with PBM with or without biliary dilatation and HCPBD were 13, 67, and 12%, being significantly higher than in controls (p < 0.05, p < 0.01, and p < 0.05). Pancreatic ductal reflux was detected in 11 (85%) of 13 patients with HCPBD in whom postoperative T tube cholangiograms were performed, and acute pancreatitis occurred in 14 (24%) of the 50 patients with HCPBD. CONCLUSIONS: HCPBD may be an intermediate variant of PBM. It is necessary to pay attention to an associated gallbladder carcinoma in patients with HCPBD as well as in those with PBM.

Adolescent↗

PubMedDate not supplied

Acute pancreatitis and a long common channel.

BACKGROUND: As sphincter action does not functionally affect the union in pancreaticobiliary maljunction (PBM), two-way regurgitation occurs. We investigated the features of acute pancreatitis associated with patients displaying a long common channel. METHODS: We reviewed 3210 endoscopic retrograde cholangiopancreatograms. PBM was diagnosed in 107 patients with a long common channel in which communication between the pancreatic and bile duct was maintained even during sphincter contraction. High confluence of pancreaticobiliary ducts (HCPBD) was diagnosed in 60 patients with a common channel >or=6 mm long in which communication between the two ducts was occluded with sphincter contraction. RESULTS: Of patients with PBM, four had acute pancreatitis. Etiology of acute pancreatitis in the two patients was suspected to involve impaction in a long common channel. Of patients with HCPBD, 17 displayed acute pancreatitis. Three patients had a history of excessive alcohol intake and 10 patients were associated with choledocholithiasis or cholecystitis. The remaining four patients had no history of them. CONCLUSIONS: Acute pancreatitis occurs in 13% of patients with a long common channel. Obstruction of a long common channel by stones easily induces bile flow into the pancreas. Even if no obstruction is present, biliopancreatic reflux induces acute pancreatitis in some patients.

Acute Disease↗

PubMedDate not supplied

Extrapancreatic lesions in autoimmune pancreatitis.

GOALS: To examine extrapancreatic lesions associated with autoimmune pancreatitis. BACKGROUND: Autoimmune pancreatitis is a unique clinical entity proposed recently, and is reported to occasionally be associated with other autoimmune diseases. STUDY: Extrapancreatic lesions were examined clinically, radiologically, and histologically in 25 patients with autoimmune pancreatitis. RESULTS: Stenosis of the bile duct was observed in 22 patients (lower bile duct [n = 19], upper bile duct [n = 1], intrahepatic bile duct [n = 2]). Marked extrapancreatic bile duct wall thickening not associated with obvious cholangiographic abnormality was seen on ultrasound in 3 patients. Enlargement of the salivary glands and cervical lymph nodes was detected in 4 patients. Abdominal lymphadenopathy was observed in 5 of 8 patients at laparotomy. Retroperitoneal fibrosis was noted in 2 patients. Obliterative phlebitis of the pancreatic and peripancreatic veins was observed histologically in all 6 resected specimens. Marked stenosis of the portal vein and encasement of the peripancreatic arteries was observed in 4 and 8 of 14 patients who underwent abdominal angiography, respectively. Diabetes mellitus was diagnosed in 13 patients. All associated extrapancreatic lesions except diabetes mellitus improved after steroid therapy. CONCLUSIONS: Extrapancreatic lesions found to be occasionally associated with autoimmune pancreatitis were stenosis of the bile duct, enlargement of the salivary glands, abdominal or cervical lymphadenopathy, retroperitoneal fibrosis, stenosis of the peripancreatic arteries or portal vein, and diabetes mellitus. It is possible that these lesions are induced by the same inflammatory mechanisms as autoimmune pancreatitis.

Autoimmune Diseases↗

PubMedDate not supplied

Clinical significance of the accessory pancreatic duct.

BACKGROUND/AIMS: The accessory pancreatic duct is the smaller and less constant pancreatic duct in comparison with the main pancreatic duct. We investigated the patency of the accessory pancreatic duct and its role in pancreatic pathophysiology. METHODOLOGY: Dye-injection endoscopic retrograde pancreatography was performed in 411 patients. In patients in whom the main pancreatic duct could be selectively cannulated, contrast medium with indigo carmine was injected through the catheter. Excretion of the dye from the minor duodenal papilla was observed endoscopically. RESULTS: Patency of the accessory pancreatic duct was 43% of the 291 control cases. In the 46 patients with acute pancreatitis, 8 (17%) had a patent accessory pancreatic duct. The difference in patency between this group and the normal group was significant (p < 0.01). Especially, patency of the accessory pancreatic duct was only 8% of the 13 patients with acute biliary pancreatitis. In the patients with pancreaticobiliary maljunction, biliary carcinoma occurred in 72% of patients with a nonpatent accessory pancreatic duct, but in contrast, it occurred only in 30% of those with a patent accessory pancreatic duct. This difference was significant (p < 0.05). Lower amylase level in the bile of patients with pancreaticobiliary maljunction with a patent accessory pancreatic duct was frequently observed than those with a nonpatent accessory pancreatic duct. CONCLUSIONS: A patent accessory pancreatic duct may prevent acute pancreatitis by lowering the pressure in the main pancreatic duct. In cases of pancreaticobiliary maljunction with a patent accessory pancreatic duct, the incidence of carcinogenesis of the bile duct might be lower, as the reflux of the pancreatic juice to the bile duct might be reduced by the flow of the pancreatic juice into the duodenum through the accessory pancreatic duct.

Acute Disease↗

PubMedDate not supplied

An investigation of primary malignancies associated with ampullary carcinoma.

BACKGROUND/AIMS: As ampullary carcinoma has a favorable prognosis, associated malignancies have potential prognostic significance in these patients. This study focused on the incidence and characteristics of preexisting, coexisting and subsequent malignancies in patients with ampullary carcinoma. METHODOLOGY: Sixty-four cases of ampullary carcinoma were retrospectively identified. Fifty-four patients underwent surgical resection, while in the other ten, histological diagnosis was reached after biopsy and/or autopsy. Other primary malignancies associated with ampullary carcinoma, occurring in the prediagnostic or postdiagnostic period, were investigated. The mean postdiagnostic follow-up period was 3.9 years (range, 0-23 years). RESULTS: Other malignancies occurred in 17 patients (27%), being found before (n=9), at (n=7), or after (n=5) diagnosis of ampullary carcinoma. The total number of associated lesions was 23, including one case of quadruple and four cases of triple carcinoma. The major associated malignancies were colonic carcinoma (n=9), gastric carcinoma (n=5), and uterine carcinoma (n=3). Twenty-one lesions were treated surgically or endoscopically. One patient died from synchronous extrahepatic bile duct carcinoma and one from leukemia, and one died from subsequent urinary bladder carcinoma. Development of other malignancies was related to age but not to gender, family history, adjuvant chemo/radiotherapy, or tumor pathology. CONCLUSIONS: Ampullary carcinoma is associated with a high incidence of other malignancies, particularly colonic and gastric carcinomas. The possibility of associated malignancies should therefore be considered in preoperative screening and postoperative follow-up of patients with ampullary carcinoma.

Aged↗

PubMedDate not supplied

Classification of choledochocele.

BACKGROUND/AIMS: Choledochocele is a rare abnormality of cystic or diverticular dilatation of the terminal intramural portion of the common bile duct. Because its anatomic form does not fit the criteria for pancreaticobiliary maljunction, reflux of bile or pancreatic juice has not been discussed in relation to choledochocele. Considering the flow of bile and pancreatic juice, the authors developed a new classification of choledochocele, and investigated associated pancreaticobiliary diseases. METHODOLOGY: We reviewed 82 cases of choledochocele, and classified them into three groups on cholangiopancreatographic findings; Type A (n=27): cystic dilatation of the common channel, Type B (n=31): cystic dilatation of the intramural bile duct forming the common channel, Type C (n=24): cystic dilatation of the intramural bile duct opening into the duodenum separately from the pancreatic duct. RESULTS: Biliary carcinoma was associated with 2 cases of Type A and 1 case of Type B choledochocele. Acute pancreatitis occurred in 10 Type A and 6 Type B choledochoceles. Biliary pancreatic reflux was reported in 4 cases of Type A and 1 case of Type B. Marked elevation of amylase in the bile was reported in 5 Type A and 5 Type B choledochoceles. CONCLUSIONS: In choledochoceles forming a common channel (Type A and B), two-way regurgitation may occur, and induce acute pancreatitis and biliary carcinoma. This classification of choledochocele is useful for analysis of pathophysiology and determination of therapeutic strategy.

Adolescent↗

PubMedDate not supplied

Pancreatitis associated with congenital abnormalities of the pancreaticobiliary system.

BACKGROUND/AIMS: The relationship between pancreas divisum and pancreatitis remains controversial. The aim of this study was to examine the frequency and features of pancreatitis associated with congenital abnormalities of the pancreaticobiliary system, and the role that these malformations have in the occurrence of pancreatitis. METHODOLOGY: We retrospectively examined endoscopic retrograde cholangiopancreatograms of 6850 patients including 186 patients who were diagnosed clinically as having acute pancreatitis and 211 who were diagnosed as having chronic pancreatitis. RESULTS: A total of 175 patients were diagnosed as having congenital abnormalities of pancreaticobiliary system. Acute and chronic pancreatitis was associated respectively with 3.0% and 5.0% of patients with pancreaticobiliary maljunction (n=100), 17.1% and 28.6% of those with pancreas divisum (n=35), 6.6% and 20.0% of those with partial pancreas divisum (n=30), and 16.7% and 33.3% of those with choledochocele (n=6). These anomalies were present in 6.5% and 10.9% of patients with acute and chronic pancreatitis, respectively. Isolated chronic dorsal pancreatitis was detected in 8 patients with pancreas divisum. In chronic pancreatitis associated with pancreaticobiliary maljunction, pancreatic stones or protein plugs were situated only in the dilated common channel or main pancreatic duct of the head. CONCLUSIONS: Congenital abnormalities of the pancreaticobiliary system constitute one etiology of pancreatitis.

Acute Disease↗

PubMedDate not supplied

Thermo-chemo-radiotherapy for advanced gallbladder carcinoma.

BACKGROUND/AIMS: Many gallbladder carcinomas are detected at an advanced stage, and the outcome of the patients with these tumors is dismal despite aggressive tumor removal. We have treated advanced gallbladder carcinoma with chemoradiotherapy combined with hyperthermia. In this study, clinical effectiveness of thermo-chemo-radiotherapy (TCRT) for advanced gallbladder carcinoma was evaluated in comparison with other treatment modalities. METHODOLOGY: Two hundred and seventy patients with advanced gallbladder carcinoma (Stage VI) were treated. According to treatments received, they were divided into five groups as follows: group 1; 30 patients treated with TCRT, group 2; 19 patients underwent R0-resection, group 3; 39 patients underwent R1,2-resection, group 4; 57 patients treated with chemo- and/or radiotherapy, group 5; 125 patients with only supportive therapy. RESULTS: In group 1, there were 19 objective responses (5 complete response and 14 partial response) in respect to tumor regression, and 15 (6 complete response and 9 partial response) of 20 patients with obstructed bile duct showed resolution of the bile duct. The survival rate was best in group 2. A significant improvement of long-term survival was exhibited in group 1 and 3 compared to group 4 and 5, and there was no significant difference between group 1 and 3 (p<0.01). CONCLUSIONS: TCRT can produce significant response and improvement of survival time in patients with advanced gallbladder carcinoma, and may be a favorable alternative to aggressive surgical approaches.

Adult↗

PubMedDate not supplied

Chronic pancreatitis progressing from segmental lesions.

BACKGROUND/AIMS: Chronic pancreatitis is histologically and functionally a progressive disease. To examine the natural history of chronic pancreatitis, we evaluated serial pancreatography in cases of chronic pancreatitis, focusing on the progression of diffuse-type chronic pancreatitis from the segmental type. METHODOLOGY: We reviewed 57 patients with chronic pancreatitis who had undergone endoscopic retrograde pancreatography on more than 2 occasions at intervals of at least 1 year. Cases of chronic pancreatitis were categorized as diffuse (n=37) and segmental (n=20) on the findings of initial endoscopic retrograde pancreatography. RESULTS: Twenty-three cases of diffuse-type chronic pancreatitis showed progression of pancreatic duct abnormalities. Segmental abnormalities of the main pancreatic duct at the body or tail of the pancreas spread to the head of the pancreas in 8 cases. Etiologies of these cases of chronic pancreatitis were alcoholic, in which patients continued drinking after initial endoscopic retrograde pancreatography. In 2 patients who underwent distal pancreatectomy, although segmental lesions showed typical histological findings of alcoholic chronic pancreatitis, appearances near the margin of these lesions were almost normal or indicated slight interlobular fibrosis. CONCLUSIONS: The pancreatic tail might represent the site of the initial lesion in some cases of alcoholic pancreatitis.

Adult↗

PubMedDate not supplied

Digestion and absorption of patients with autoimmune pancreatitis.

BACKGROUND/AIMS: In patients with autoimmune pancreatitis, radiological, serological and pancreatic functional abnormalities usually improve with steroid therapy. However, no studies have specifically focused on digestion and absorption in such patients. This study aims to investigate digestion and absorption, in addition to pancreatic endocrine and exocrine function, and their responses to steroid therapy in patients with autoimmune pancreatitis. METHODOLOGY: Ideal body weight index, levels of serum albumin, total cholesterol and glucose, or glycosylated hemoglobin values were investigated in 22 patients with autoimmune pancreatitis. N-benzoyl-L-tyrosyl-paraminobenzoic acid excretion test was performed in 9 patients. In 10 patients treated with steroids, these factors were examined again about 2 months after medication. RESULTS: Levels of serum albumin decreased, while ideal body weight index and levels of serum albumin and cholesterol significantly increased after steroid therapy. Eleven (50%) patients showed evidence of diabetes mellitus, but this improved in 6 of 8 patients treated with steroids. Pancreatic exocrine function was reduced in 88% of patients. Impaired pancreatic exocrine function improved after steroid therapy in 3 of 7 patients treated. CONCLUSIONS: Mild malnutrition as well as impaired pancreatic endocrine and exocrine function were frequently detected in patients with autoimmune pancreatitis. Steroid therapy was occasionally effective for these conditions.

Adult↗

PubMedDate not supplied

Biliary carcinoma risk in patients with pancreaticobiliary maljunction and the degree of extrahepatic bile duct dilatation.

BACKGROUND/AIMS: Pancreaticobiliary maljunction (PBM) carries a high risk of biliary carcinoma. This study aimed to examine the biliary complications of patients with PBM in relation to the degree of extra-hepatic bile duct dilatation. METHODOLOGY: Ninety-eight cases of PBM could be divided into 5 groups according to the maximum diameter of the extrahepatic bile duct: < or = 10mm, 11-15mm, 16-20mm, 21-30mm, > or = 31mm. The clinicopathological findings of biliary carcinomas associated with PBM were compared with 232 cases of gallbladder carcinoma and 159 cases of bile duct carcinoma that were not associated with PBM. RESULTS: Gallbladder carcinoma occurred in 36 of 65 patients (55%) with PBM whose maximum diameter of the extrahepatic bile duct was < or = 30mm, but no gallbladder carcinoma occurred in patients with PBM whose diameter was > or = 31mm. Bile duct carcinoma occurred in 6 of 52 patients (12%) with PBM whose diameter was > or = 21mm, but no bile duct carcinoma occurred in patients with PBM whose diameter was < or = 20mm. The age at diagnosis of the patients with gallbladder or bile duct carcinoma associated with PBM was significantly younger than those without PBM (p<0.01). CONCLUSIONS: PBM with an extrahepatic bile duct diameter < or = 30mm is associated with a high risk of gallbladder carcinoma. PBM with an extrahepatic bile duct diameter > or = 21mm is associated with a high risk of bile duct carcinoma. Prophylactic cholecystectomy is recommended for patients with PBM without biliary dilatation.

Adolescent↗

PubMedDate not supplied

Comparison of radiological and histological findings in autoimmune pancreatitis.

BACKGROUND/AIMS: Autoimmune pancreatitis displays radiological findings that are sometimes difficult to differentiate from pancreatic carcinoma. To understand the essential radiological features of autoimmune pancreatitis (AIP), we compared imaging and histological findings in resected AIP specimens. METHODOLOGY: Findings of ultrasonography, computed tomography, endoscopic retrograde cholangiopancreatography and angiography were examined retrospectively for 6 patients who underwent pancreatoduodenectomy on suspicion of pancreatic carcinoma, and compared with histological findings of the resected specimens. RESULTS: Ultrasonography showed an enlarged hypoechoic pancreas with sausage-like appearance and no lobulation in the contour of the pancreas. On computed tomography imaging, delayed enhancement of the swollen pancreatic parenchyma became evident. Dense lymphoplasmacytic infiltration with fibrosis involving peripancreatic tissue was observed throughout almost the entire pancreas. Periductal non-occlusive fibrosis with lymphoplasmacytic infiltration induced narrowing of the pancreatic duct. Stenosis of the common bile duct is frequently associated with autoimmune pancreatitis and is induced by diffuse thickening of the duct wall by the same inflammatory process as that of the pancreas. The fibroinflammatory process also involves blood vessels. CONCLUSIONS: Characteristic radiological findings of autoimmune pancreatitis are induced with systemic histological changes of lymphoplasmacytic infiltration with fibrosis, and differ from schirrous invasion of pancreatic carcinoma.

Aged↗