Mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater: a case report.

BACKGROUND: Mixed neuroendocrine-non-neuroendocrine neoplasms of the ampulla of Vater are rare and heterogenous, making it difficult to achieve a definitive preoperative diagnosis. Herein, we describe a patient in whom a provisional diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater was made preoperatively. CASE PRESENTATION: Computed tomography revealed an enhancing periampullary tumor in a 69-year-old man with obstructive jaundice. Subsequent duodenoscopy revealed an ulcerated lesion in the swollen ampulla of Vater, from which six biopsies were collected. Pathological examination revealed adenocarcinoma in five of them. The remaining one was a neuroendocrine neoplasm according to immunohistochemical analysis. With a provisional diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater, the patient underwent subtotal stomach-preserving pancreaticoduodenectomy with modified Child's reconstruction and was discharged without complications. Pathological examination revealed both adenocarcinoma and neuroendocrine carcinomas, each accounting for ≥ 30% of the tumor, resulting in a definitive diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater. Lymph node metastases with neuroendocrine components were also observed. Adjuvant chemotherapy was not administered because of the patient's renal dysfunction. Liver and lymph node metastases were detected 2 months after surgery, the neuroendocrine component being considered responsible for that relapse. The patient underwent platinum-based chemotherapy at 50% dosage, which initially resulted in significant tumor shrinkage; however, he died 6 months after surgery. CONCLUSIONS: While these tumors' heterogeneity make definitive preoperative diagnosis of mixed neuroendocrine-non-neuroendocrine neoplasm of the ampulla of Vater difficult, the possibility of this disease can be considered by careful examination. Further study is needed to establish the optimal diagnostic criteria and treatment strategy.

Incidence and appropriate management of drug-induced interstitial lung disease in Japanese patients with unresectable pancreatic cancer: A multicenter retrospective study.

AIM: Drug-induced interstitial lung disease (DI-ILD) is a serious adverse event during chemotherapy. This study aimed to obtain real-world data of the incidence, clinical characteristics, predictive factors, and prognosis of patients with pancreatic cancer who developed DI-ILD. METHODS: In patients with locally advanced or metastatic pancreatic cancer who underwent standard chemotherapy at our hospital and its participating facilities between April 2014 and March 2019, the clinical features, occurrence rate and clinical course of DI-ILD, and prognosis were retrospectively evaluated. RESULTS: Altogether, 390 patients were finally enrolled. DI-ILD occurred in 24 cases (6.2%). The median period from diagnosis of pancreatic cancer to the onset of DI-ILD was 2.2 months (.6-13.3 months). The rate of DI-ILD onset according to each regimen was 5.8% of gemcitabine (GEM) plus albumin-bound paclitaxel therapy (18/308), 3.8% of GEM (4/106), and 2.3% of FOLFIRINOX (2/88). The incidence of DI-ILD in GEM-based regimens was significantly higher than that in non-GEM-based regimens (p < .01). The median overall survival (OS) of the patients with and without DI-ILD after propensity score matching was 11.5 months and 11.4 months (p = .99), respectively. After the resolution of DI-ILD, no statistical significance in the median OS of the patients with and without subsequent treatment (11.0 vs. 6.8 months, p = .18) was observed. CONCLUSION: DI-ILD is not a rare adverse event in the current standard chemotherapy for pancreatic cancer in Japan. With appropriate management of DI-ILD, the prognosis of patients with DI-ILD can be equivalent to that of patients without DI-ILD.

Treatment Effect and Safety of Nanoliposomal Irinotecan with Fluorouracil and Folinic Acid after Gemcitabine-Based Therapy in Patients with Advanced Pancreatic Cancer: A Multicenter, Prospective Observational Study.

Although the combination of nanoliposomal irinotecan plus fluorouracil/folinic acid (nal-IRI/FF) exhibited survival benefits in gemcitabine-refractory patients with advanced pancreatic cancer (APC) in the phase III NAPOLI-1 trial, there is limited data on the efficacy and safety of this regimen in real-world settings in Japan. This multicenter, prospective observational study enrolled patients with APC who received nal-IRI/FF after a gemcitabine-based regimen from July 2020 to June 2021. We collected and analyzed clinical data and conducted survival and multivariate analyses. Thirty-one (78%) of the 40 patients had metastases. Nal-IRI/FF was the second-line therapy in 36 patients (90%). The median duration was 3.2 months. The disease control rate was 57%. The median progression-free survival and overall survival (OS) were 4.5 months (95% confidence interval [CI]: 2.8−5.5) and 7.4 months (95% CI: 5.1−10.6), respectively. Common ≥grade 3 toxicities included neutropenia (28%) and fatigue (23%). Fatigue led to treatment discontinuation in 6 out of 10 patients. Multivariate analysis showed that a neutrophil-to-lymphocyte ratio > 4 was a significant risk factor for a short OS (hazard ratio (HR) = 3.08, 95% CI: 1.21−7.85, p = 0.02). In conclusion, nal-IRI/FF is an appropriate treatment option for APC following gemcitabine-containing regimens.

Neutrophil-to-lymphocyte ratio and mural nodule height as predictive factors for malignant intraductal papillary mucinous neoplasms.

BACKGROUND: Accurate preoperative prediction for malignant IPMN is still challenging. The aim of this study was to investigate the validity of neutrophil-to-lymphocyte ratio (NLR) and mural nodule height (MNH) for predicting malignant intraductal papillary mucinous neoplasm (IPMN). METHODS: The medical records of 60 patients who underwent pancreatectomy for IPMN were retrospectively reviewed. RESULTS: NLR tended to be higher in malignant IPMN (median: 2.23) than in benign IPMN (median: 2.04; p = .14). MNH was significantly greater in malignant IPMN (median: 16 mm) than in benign IPMN (median: 8 mm; p < .01). The optimal cutoff values for the NLR and MNH were 3.60 and 11 mm, respectively. The sensitivity and specificity of NLR ≥3.60 for predicting malignant IPMN were 40% and 93%, and those of MNH ≥11 mm were 73% and 77%, respectively. Univariate analysis revealed that NLR ≥3.60 (p < .01) and MNH ≥11 mm (p < .01) were significant predictive factors. On multivariate analysis, enhanced solid component was identified as an independent factor, but NLR ≥3.60 and MNH ≥11 mm were not. CONCLUSIONS: NLR and MNH are suboptimal tests in predicting malignant IPMN; however, they can be useful to assist in clinical decision-making.

Validity of the management strategy for intraductal papillary mucinous neoplasm advocated by the international consensus guidelines 2012: a retrospective review.

PURPOSE: The aim of this study was to investigate the validity of the management strategy for intraductal papillary mucinous neoplasms (IPMNs) advocated by the international consensus guidelines 2012 (ICG2012). METHODS: The medical records of 49 patients who underwent pancreatectomy for IPMN were retrospectively reviewed. RESULTS: According to preoperative imaging, 10 patients (20 %) had main-duct IPMNs, 20 (41 %) had mixed IPMNs, and 19 (39 %) had branch-duct IPMNs, with malignancy frequencies of 80, 15, and 37 %, respectively. Twenty-seven patients had high-risk stigmata and 21 had worrisome features, with malignancy frequencies of 59 and 10 %, respectively. The sensitivity, specificity, and positive and negative predictive values of high-risk stigmata for malignancy were 88, 65, 59, and 91 %, respectively. Lesions were malignant in 88 % of patients with an enhanced solid component, which was significantly correlated with the prevalence of malignancy (P < 0.01). However, of the 10 patients who underwent pancreatectomy solely due to a main pancreatic dilation of ≥10 mm, 9 (90 %) had benign IPMNs. CONCLUSIONS: Many mixed IPMNs defined according to ICG2012 are benign. Although the management strategy advocated by ICG2012 has been improved relative to the Sendai criteria, the different high-risk stigmata carry unequal weights. Consequently, ICG2012 remains suboptimal for predicting malignant IPMN.

Promising biological therapies for ulcerative colitis: A review of the literature.

Ulcerative colitis (UC) is a chronic lifelong condition characterized by alternating flare-ups and remission. There is no single known unifying cause, and the pathogenesis is multifactorial, with genetics, environmental factors, microbiota, and the immune system all playing roles. Current treatment modalities for UC include 5-aminosalicylates, corticosteroids, immunosuppressants (including purine antimetabolites, cyclosporine, and tacrolimus), and surgery. Therapeutic goals for UC are evolving. Medical treatment aims to induce remission and prevent relapse of disease activity. Infliximab, an anti-tumor necrosis factor (TNF)-α monoclonal antibody, is the first biological agent for the treatment of UC. Over the last decade, infliximab and adalimumab (anti-TNF-α agents) have been used for moderate to severe UC, and have been shown to be effective in inducing and maintaining remission. Recent studies have indicated that golimumab (another anti-TNF-α agent), tofacitinib (a Janus kinase inhibitor), and vedolizumab and etrolizumab (integrin antagonists), achieved good clinical remission and response rates in UC. Recently, golimumab and vedolizumab have been approved for UC by the United States Food and Drug Administration. Vedolizumab may be used as a first-line alternative to anti-TNF-α therapy in patients with an inadequate response to corticosteroids and/or immunosuppressants. Here, we provide updated information on various biological agents in the treatment of UC.

A synchronous pancreatic neuroendocrine tumor and duodenal gastrointestinal stromal tumor.

We recently encountered the case of a patient with a synchronous duodenal gastrointestinal stromal tumor (GIST) and pancreatic neuroendocrine tumor (PNET). This is the first report of this specific combination of multiple primary tumors, although three cases involving both PNET and gastric GIST have previously been reported. Since the duodenal GIST developed close to the pancreatic uncus in this case, we considered the possibility of multiple PNETs in the differential diagnosis. However, a histopathological examination using endoscopic ultrasonography-guided fine-needle aspiration confirmed the diagnosis of multiple primary lesions, involving PNET and duodenal GIST.

A sustained prostacyclin analog, ONO-1301, attenuates pancreatic fibrosis in experimental chronic pancreatitis induced by dibutyltin dichloride in rats.

BACKGROUND: ONO-1301, a novel sustained-release prostacyclin agonist, has an anti-fibrotic effect on the lungs, heart, and kidneys that is partly associated with the induction of hepatocyte growth factor (HGF). This study examined the anti-fibrotic effect of ONO-1301 on chronic pancreatitis (CP) progression. METHODS: CP was induced in rats in vivo by dibutyltin dichloride (DBTC). Seven days after DBTC injection (day 7), a slow-release form of ONO-1301 (10 mg/kg; ONO-1301-treated group) or vehicle (DBTC-treated group) was injected. On days 14 and 28, we evaluated the histopathological CP score and mRNA expressions of HGF, cytokines, and collagen in the pancreas by real-time RT-PCR. In vitro, monocytes and pancreatic stellate cells (PSCs) were isolated from normal rat spleen and pancreas, respectively. The cytokine and collagen expressions of monocytes and PSCs were detected by real-time RT-PCR, and PSCs proliferation was examined by BrdU assay. RESULTS: Histopathological CP scores in vivo improved in the ONO-1301-treated group compared to the DBTC-treated group, particularly inflammatory cell infiltration on day 14 and interstitial fibrosis on day 28. HGF mRNA increased significantly after ONO-1301 administration, whereas IL-1ß, TNF-α, TGF-ß, MCP-1, and collagen mRNA decreased significantly. Cytokine expression in monocytes was suppressed in vitro not only by HGF, but also ONO-1301 alone. However, neither ONO-1301 nor HGF affected the proliferation, or cytokine or collagen expression of PSCs. CONCLUSIONS: ONO-1301 suppresses pancreatic fibrosis in the DBTC-induced CP model by inhibiting monocyte activity not only with induction of HGF but also by ONO-1301 itself.

Large area of walled-off pancreatic necrosis successfully treated by endoscopic necrosectomy using a grasping-type scissors forceps.

Endoscopic necrosectomy (EN) for walled-off pancreatic necrosis (WOPN) is less invasive than surgical treatment and has become the first choice for pancreatic abscess. EN is usually carried out with several devices including snares, baskets, and grasping forceps. Occasionally, we have encountered cases in which EN has not been satisfactorily carried out, and there is pressure for further innovation in EN. Here, we describe a case of a large area of WOPN that was successfully treated by EN with endoscopic submucosal dissection and associated techniques, which facilitated removal of necrotic tissues. A 60-year-old man was referred to our hospital for WOPN as a complication of necrotizing pancreatitis. As a result of his complicating conditions including ischemic heart disease, uncontrollable arrhythmia, chronic renal failure, and persistent pleural effusion, he was deemed a poor surgical candidate. Although EN with conventional devices was carried out for five sessions, we could not remove the dense and massive necrotic tissues. At the sixth EN session, the Clutch Cutter device (Fujifilm, Tokyo, Japan) was used to remove the necrotic tissues, without major complications. This is believed to be the first report of EN using the Clutch Cutter for successful treatment of WOPN.

Endoscopic approach through the minor papilla for the management of pancreatic diseases.

AIM: To clarify the efficacy and safety of an endoscopic approach through the minor papilla for the management of pancreatic diseases. METHODS: This study included 44 endoscopic retrograde cholangiopancreatography (ERCP) procedures performed in 34 patients using a minor papilla approach between April 2007 and March 2012. We retrospectively evaluated the clinical profiles of the patients, the endoscopic interventions, short-term outcomes, and complications. RESULTS: Of 44 ERCPs, 26 were diagnostic ERCP, and 18 were therapeutic ERCP. The most common cause of difficult access to the main pancreatic duct through the major papilla was pancreas divisum followed by distortion of Wirsung's duct. The overall success rate of minor papilla cannulation was 80% (35/44), which was significantly improved by wire-guided cannulation (P = 0.04). Endoscopic minor papillotomy (EMP) was performed in 17 of 34 patients (50%) using a needle-knife (13/17) or a pull-type papillotome (4/17). EMP with pancreatic stent placement, which was the main therapeutic option for patients with chronic pancreatitis, recurrent acute pancreatitis, and pancreatic pseudocyst, resulted in short-term clinical improvement in 83% of patients. Mild post-ERCP pancreatitis occurred as an early complication in 2 cases (4.5%). CONCLUSION: The endoscopic minor papilla approach is technically feasible, safe, and effective when the procedure is performed in a high-volume referral center by experienced endoscopists.

Retroperitoneal fibrosis associated with immunoglobulin G4-related disease.

Retroperitoneal fibrosis is a rare disease characterized by the development of inflammation and fibrosis in the soft tissues of the retroperitoneum and other abdominal organs. Retroperitoneal fibrosis can be of 2 types: idiopathic and secondary. The recently advocated concept and diagnostic criteria of immunoglobulin G4 (IgG4)-related disease, derived from research on autoimmune pancreatitis (AIP), has led to widespread recognition of retroperitoneal fibrosis as a condition caused by IgG4-related disease. We now know that previously diagnosed idiopathic retroperitoneal fibrosis includes IgG4-related disease; however, the actual prevalence is unclear. Conversely, some reports on AIP suggest that retroperitoneal fibrosis is concurrently found in about 10% of IgG4-related disease. Because retroperitoneal fibrosis has no specific symptoms, diagnosis is primarily based on diagnostic imaging (computed tomography and magnetic resonance imaging), which is also useful in evaluating the effect of therapy. Idiopathic retroperitoneal fibrosis can occur at different times with other lesions of IgG4-related disease including AIP. Thus, the IgG4 assay is recommended to diagnose idiopathic retroperitoneal fibrosis. High serum IgG4 levels should be treated and monitored as a symptom of IgG4-related disease. The first line of treatment for retroperitoneal fibrosis is steroid therapy regardless of its cause. For patients with concurrent AIP, i.e., IgG4-related retroperitoneal fibrosis, the starting dose of steroid is usually 30-40 mg/d. The response to steroid therapy is generally favorable. In most cases, the pancreatic lesion and retroperitoneal fibrosis improve after the initial treatment. However, the epidemiology, treatment for recurring retroperitoneal fibrosis, and long-term prognosis are still largely unknown. Further analysis of such cases and research are necessary.

The current strategy for managing pancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1) is an inherited autosomal dominant disease presenting with pancreatic neuroendocrine tumors (pNETs), parathyroid tumors, or pituitary tumors. Using the PubMed database, we reviewed the literature on information regarding the proper diagnosis and treatment of MEN1-associated pNET. Many cases of MEN1-associated pNET are functioning pNETs. Gastrinomas and insulinomas tend to occur frequently in the duodenum and pancreas, respectively. In addition to diagnostic imaging, the selective arterial secretagogue injection test (SASI test) is useful for localizing functioning pNET. The standard treatment is surgical resection. However, in the case of a functioning pNET, the tumor should first be accurately located using the SASI test before an appropriate surgical method is selected. In cases of a MEN1-associated non-functioning pNET that exceeds 2 cm in diameter, the incidence of distant metastasis is significantly increased, and surgery is recommended. In cases of unresectable pNET, a somatostatin analog has been shown to demonstrate antitumor effects and is considered to be a promising treatment. In addition, molecular-targeted drugs have recently been found to be effective in phase III clinical trials.

Cytosolic double-stranded DNA as a damage-associated molecular pattern induces the inflammatory response in rat pancreatic stellate cells: a plausible mechanism for tissue injury-associated pancreatitis.

Pancreatitis is an inflammatory disease of unknown causes. There are many triggers causing pancreatitis, such as alcohol, common bile duct stone, virus and congenital or acquired stenosis of main pancreatic duct, which often involve tissue injuries. Pancreatitis often occurs in sterile condition, where the dead/dying pancreatic parenchymal cells and the necrotic tissues derived from self-digested-pancreas were observed. However, the causal relationship between tissue injury and pancreatitis and how tissue injury could induce the inflammation of the pancreas were not elucidated fully until now. This study demonstrates that cytosolic double-stranded DNA increases the expression of several inflammatory genes (cytokines, chemokines, type I interferon, and major histocompatibility complex) in rat pancreatic stellate cells. Furthermore, these increase accompanied the multiple signal molecules genes, such as interferon regulatory factors, nuclear factor-kappa B, low-molecular-weight protein 2, and transporter associated with antigen processing 1. We suggest that this phenomenon is a plausible mechanism that might explain how cell damage of the pancreas or tissue injury triggers acute, chronic, and autoimmune pancreatitis; it is potentially relevant to host immune responses induced during alcohol consumption or other causes.

Relationship between pancreatic and/or extrapancreatic lesions and serum IgG and IgG4 levels in IgG4-related diseases.

OBJECTIVE: We aimed to investigate the relationship between the number of involved organs or regions and serum immunoglobulin G (IgG) and immunoglobulin G4 (IgG4) levels. METHODS: The number of pancreatic and/or extrapancreatic lesions and serum IgG and IgG4 levels were examined by groups in 46 patients with IgG4-related diseases at diagnosis prior to the initiation of steroid treatment: group A (one region involved, n=7), group B (two regions involved, n=11), group C (three regions involved, n=12), group D (four regions involved, n=9) and group E (five to seven regions involved, n=7). RESULTS: Both serum IgG and IgG4 levels increased with the number of inflamed regions. Mean serum IgG levels were 15.11, 18.65, 20.92, 23.29 and 30.98 g/L while the mean IgG4 levels were 3.99, 4.70, 4.70, 9.86 and 16.49 g/L in group A, B, C, D and E, respectively. Regression analysis also suggested that IgG4 was positively correlated with the number of regions involved. Additionally, serum IgG4 was higher in patients with multiple lesions when accompanied by sclerosing sialadenitis. CONCLUSION: Patients having IgG4-related disease with high serum IgG and IgG4 levels should be systematically examined for involved lesions.

Paclitaxel-based chemotherapy for advanced pancreatic cancer after gemcitabine-based therapy failure: a case series of 5 patients.

BACKGROUND/OBJECTIVES: Gemcitabine (GEM) is a gold-standard chemotherapy agent for advanced pancreatic cancer. Because of the malignant character of the disease, nearly all patients show disease progression despite treatment with GEM-based chemotherapy; therefore, second-line chemotherapy may be beneficial for these patients. We report a retrospective analysis of 5 patients with advanced pancreatic cancer, treated with a paclitaxel-containing regimen as second-, third- or fourth-line chemotherapy after various therapies, such as a GEM-based regimen, S-1 regimen, and chemoradiation. We retrospectively analyzed the efficacy and adverse events, and evaluated the paclitaxel-containing regimens. A review of the literature is also discussed. RESULTS: The median overall survival from the start of salvage therapy was 10.7 months. The disease control rate of the paclitaxel-containing regimen according to RECIST criteria was 60%, including complete response in 0 patients, partial response in 3, and stable disease in 2. Two patients had malignant ascites at the start of this salvage therapy, and in both of them the ascites and clinical complaints improved. Grade 3 and 4 hematological adverse events were observed in 2 patients and 1 patient, respectively. CONCLUSION: Salvage paclitaxel-based therapy could be beneficial to advanced pancreatic cancer patients who maintain good performance status after several chemotherapy failures.

Bacterial DNA promotes proliferation of rat pancreatic stellate cells thorough toll-like receptor 9: potential mechanisms for bacterially induced fibrosis.

OBJECTIVES: We hoped to clarify the possible role of CpG DNA as a trigger factor for overt pancreatic inflammation of pancreatic stellate cells (PSCs). METHODS: Pancreatic stellate cells were isolated from the male Lewis rat. The expression of Toll-like receptor 9 (TLR9) messenger RNA and protein were evaluated by reverse transcription-polymerase chain reaction and immunofluorescent cytochemistry. Internalization of CpG DNA was analyzed by confocal laser scanning microscopy. Pancreatic stellate cells were incubated with CpG DNA, and then cell proliferation and migration were assessed. RESULTS: Constitutive expression of TLR9 occurs at the messenger RNA and protein levels. After several minutes of CpG DNA administration, CpG DNA was observed on the cell membrane surface and in the cytoplasm and found to be translocating into the perinucleus of PSCs. Pancreatic stellate cells migrated and proliferated in dose- and time-dependent manners in response to simulation by CpG DNA. Proliferation of PSCs was observed 3 hours after administration (earlier than platelet-derived growth factor-induced proliferation), suggesting that PSCs respond readily to provide innate immunity. Endosomal acidification inhibitors attenuated CpG DNA-induced signaling, leading to suppression of DNA synthesis by PSCs. CONCLUSIONS: Our findings demonstrate that bacterial DNA promotes migration and proliferation of PSCs and suggest that bacterial DNA can initiate and sustain pancreatic inflammation and fibrosis by means of TLR9.

Characteristics of pancreatic diabetes in patients with autoimmune pancreatitis.

OBJECTIVE: Although patients with autoimmune pancreatitis (AIP) tend to have concurrent diverse disorders, very few studies have focused on diabetes mellitus (DM) coexisting with AIP. METHODS: In total 102 AIP patients with DM were divided into three groups. Those with DM before the onset of AIP were labeled group A (n=35), those who developed DM and AIP simultaneously were labeled group B (n=58) and those who developed DM after steroid therapy for AIP were labeled group C (n=9). The characteristics of DM among the three groups were evaluated. RESULTS: No significant differences were noted in the age of DM onset among the three groups. However, the mean duration of DM was significantly longer in group A (8.7 years) than in groups B and C. AIP developed 6.8 years after DM onset in group A, whereas it developed 1.8 years after steroid therapy in group C. Group A had the highest rate (25.7%) of family members with a history of AIP. Levels of serum albumin, total cholesterol and triglyceride were significantly lower in group A. No correlations were found between glycated hemoglobin and benzoyl-tyrosyl para-aminobenzoic acid. Hypoglycemia was observed in 20% of patients under insulin therapy. Most of them were habitual drinkers and received no pancreatic enzymes. Group A showed a high prevalence of retinopathy, nephropathy and macrovascular disorders than group B. CONCLUSION: Aspects of AIP-associated pancreatic diabetes were clarified. AIP-associated DM must be controlled by a full assessment of the pancreatic endocrine and exocrine function.

A case of lipomatous pseudohypertrophy of the pancreas diagnosed by typical imaging.

CONTEXT: Lipomatous pseudohypertrophy of the pancreas is an extremely rare disease, and is characterized by the replacement of pancreatic acinar cells with adipose tissue, although the pancreatic duct and islets are preserved. CASE REPORT: We report the case of a 64-year-old female who was undergoing treatment for Hashimoto's disease at a nearby clinic. For the previous two years, she had experienced an unpleasant feeling in the upper abdominal area after eating oily foods. For the previous six months, she had also suffered from lower-back pain, and presented at our hospital. Abdominal computed tomography and magnetic resonance imaging revealed marked fat replacement over the entire pancreas. Endoscopic retrograde cholangiopancreatography revealed no anatomical abnormality or narrowing of the main pancreatic duct; the main pancreatic duct was normal up to the pancreatic tail and the branches of the pancreatic duct did not show any abnormalities. While the serum levels of the pancreatic enzymes were considerably low, according to the data of the pancreatic exocrine function test (N-benzoyl-tyrosyl-p-aminobenzoic acid test), endocrine function was maintained. On the basis of the abovementioned findings, we diagnosed lipomatous pseudohypertrophy of the pancreas. CONCLUSIONS: Lipomatous pseudohypertrophy of the pancreas is a very rare disease characterized by the disappearance of pancreatic exocrine tissue due to adipose tissue replacement, although the pancreatic duct and islets remain intact. Even though it has been suggested that the diagnosis of lipomatous pseudohypertrophy of the pancreas should be based on histological findings, this case indicated the possibility that lipomatous pseudohypertrophy of the pancreas may be diagnosed solely by typical imaging findings and serological data.