Autoimmune pancreatitis with multifocal lesions

Synchronous Pancreatic Masses

Any mass lesion in the pancreas usually raises the possibility of undiagnosed pancreatic cancer. With the advancement of imaging modalities, we are seeing an increasing number of incidental findings, some of which may be clinically significant. When dealing with incidental pancreatic findings, it is critical to keep a broad differential in mind in addition to ruling out pancreatic malignancy. We present 3 rare cases of patients with 2 or more synchronous solid masses in the pancreas caused by pancreatic cancer, type 1 autoimmune pancreatitis, and sarcoidosis.

Multiple solid pancreatic lesions: Prevalence and features of non-malignancies on dynamic enhanced CT

OBJECTIVE

To determine the prevalence of multiple solid pancreatic lesions on dynamic enhanced CT performed for suspected pancreatic diseases, and to identify CT features of non-malignancies.

METHODS

We investigated 8096 consecutive patients who underwent dynamic enhanced CT pancreas protocol at a tertiary center over 40 months. The final clinical /pathological diagnosis served as reference standard. The diagnostic accuracy of dynamic enhanced CT for non-malignancies was calculated. A univariate and multivariate analysis was conducted to identify features that predict non-malignancies.

RESULTS

Multiple solid pancreatic lesions were identified in 121 patients. The prevalence of non-malignancies was 19.8% (24/121). The most common non-malignancy was autoimmune pancreatitis (n = 21; 17.4%). Common lesions with malignant potential included neuroendocrine neoplasia (n = 62; 51.2%), ductal adenocarcinoma (n = 15; 12.4%), metastasis (n = 9; 7.4%), and lymphoma (n = 7; 5.8%). Dynamic enhanced CT had a sensitivity of 79.2% and a specificity of 92.8% for diagnosing non-malignancies. Elevated serum IgG4 level (p < 0.001), hypo-enhancement in arterial phase (p = 0.001), hyper-enhancement in equilibrium phase (p = 0.009) and location in both proximal and distal pancreas (p = 0.036) were predictors of non-malignancies, whereas pancreatic duct morphology and vascular invasion status were not.

CONCLUSION

Multiple solid pancreatic lesions were rare, with a wide spectrum. Dynamic enhanced CT provides clues for identifying non-malignancies.

Multifocal Mass Lesions in Autoimmune Pancreatitis

A 59-year-old male patient with jaundice was referred to our hospital because of mass lesions in the pancreatic head and tail. An immunological examination revealed an elevated serum IgG4 level. Computed tomography showed two clear boundary mass lesions in the pancreatic head and tail. Magnetic resonance imaging showed that the mass lesions exhibited low intensity on T1-weighted images and iso-intensity on T2-weighted images. Magnetic resonance cholangiopancreatography showed an obstruction of the main pancreatic duct in the pancreatic head and tail. The possibility of malignant tumors could not be ruled out; therefore, we performed total pancreatectomy. A histopathological examination of the nodular lesions revealed severe lymphoplasmacytic infiltration and inflammatory change around the pancreatic ducts. Immunohistochemistry revealed diffuse infiltration of IgG4-positive plasma cells in the nodules. According to these pathological findings, we diagnosed the patient with IgG4-related multifocal mass lesions of autoimmune pancreatitis (AIP). It is difficult to distinguish between focal type AIP and pancreatic cancer. We herein report a rare case of multifocal mass lesions in AIP and include bibliographical comments.

Pathologic Diagnosis of Pancreatic Adenocarcinoma in the United States: Its Status and Prognostic Value

Purpose: Even with the development of new biopsy methods, diagnosis of pancreatic cancer is sometimes without histological evidence. The aim of our study is to find out the status of pancreatic cancer patients who are diagnosed without pathologic confirm and the prognostic value of pathologic diagnosis.

Methods: We identified 52,759 pancreatic adenocarcinoma patients from the Surveillance, Epidemiology, and End Results (SEER) database. Logistic regression model was used to identify factors relating to no pathologic diagnosis. Multivariable Cox regression model identified potential prognostic factors. All statistical tests were two-sided.

Results: There were 6206 (11.76%) patients without pathologic diagnosis. Older age, reported from nursing/convalescent home/hospice or physician's office/private medical practitioner, early year of diagnosis, larger tumor size, pancreatic head cancer, unmarried patients, uninsured and stage I disease all contributed to no pathologic diagnosis. Median cause specific-survival for patients with and without pathologic diagnosis were 7.72 and 3.52 months, respectively. The HR for pathologic diagnosis was 0.92 (95% CI: 0.89-0.95), P<0.001.

Conclusions: Pathologic diagnosis was an independent prognostic factor for pancreatic adenocarcinoma patients. New diagnostic methods are needed to get the pathologic diagnosis.

CT and MRI Findings of Autoimmune Polymorph Bifocal Pancreatitis Mimicking Pancreatic Adenocarcinoma: A Case Report and Review of the Literature

Autoimmune pancreatitis is a rare type of chronic pancreatitis. It is supposed to be a pancreatic manifestation of an immune-complex modulated systemic disorder. In contrast, pancreatic adenocarcinoma is the most frequent malignant neoplasm of the pancreas. Within the rare type of focal autoimmune pancreatitis, only few presentations with multifocal pancreatic lesions have been described. Herein we report a case of a 58-year-old patient with autoimmune pancreatitis presenting with bifocal manifestations of the pancreatic head and tail, mimicking pancreatic adenocarcinoma clinically, on computed tomography and magnetic resonance imaging. Typical imaging findings of autoimmune pancreatitis are compared with typical findings in pancreatic carcinoma. The diagnostic dilemma of differentiating between both entities is discussed. A review of the present literature regarding multifocal presence of autoimmune pancreatitis is performed.

Multiple Intraglandular Metastases in a Patient with Invasive Ductal Carcinoma of the Pancreas

A 56-year-old man was admitted to our hospital for an evaluation of pancreatic lesions. Computed tomography revealed a hypoattenuating tumor in the head of the pancreas, with three other tumors detected in the body and tail. Magnetic resonance imaging showed similar enhancement patterns and signal intensities in all four lesions. The patient underwent total pancreatectomy based on a preoperative diagnosis of multiple invasive ductal carcinomas. Histopathologically, the lesion in the pancreatic head was considered to be the primary lesion, while the others were diagnosed as metastases. This is a rare case of pancreatic cancer with intraglandular metastases. The possibility of this differential diagnosis should thus be considered when imaging shows multiple hypovascular lesions in the pancreas.

Utility of PET/CT in diagnosis, staging, assessment of resectability and metabolic response of pancreatic cancer

Pancreatic cancer is one of the most common gastrointestinal tumors, with its incidence staying at a high level in both the United States and China. However, the overall 5-year survival rate of pancreatic cancer is still extremely low. Surgery remains the only potential chance for long-term survival. Early diagnosis and precise staging are crucial to make proper clinical decision for surgery candidates. Despite advances in diagnostic technology such as computed tomography (CT) and endoscopic ultrasound, diagnosis, staging and monitoring of the metabolic response remain a challenge for this devastating disease. Positron emission tomography/CT (PET/CT), a relatively novel modality, combines metabolic detection with anatomic information. It has been widely used in oncology and achieves good results in breast cancer, lung cancer and lymphoma. Its utilization in pancreatic cancer has also been widely accepted. However, the value of PET/CT in pancreatic disease is still controversial. Will PET/CT change the treatment strategy for potential surgery candidates? What kind of patients benefits most from this exam? In this review, we focus on the utility of PET/CT in diagnosis, staging, and assessment of resectability of pancreatic cancer. In addition, its ability to monitor metabolic response and recurrence after treatment will be emphasis of discussion. We hope to provide answers to the questions above, which clinicians care most about.

Autoimmune pancreatitis in the context of IgG4-related disease: Review of imaging findings

Current understanding of autoimmune pancreatitis (AIP) recognizes a histopathological subtype of the disease to fall within the spectrum of IgG4-related disease. Along with clinical, laboratory, and histopathological data, imaging plays an important role in the diagnosis and management of AIP, and more broadly, within the spectrum of IgG4-related disease. In addition to the defined role of imaging in consensus diagnostic protocols, an array of imaging modalities can provide complementary data to address specific clinical concerns. These include contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging for pancreatic parenchymal lesion localization and characterization, endoscopic retrograde and magnetic resonance cholangiopancreatography (ERCP and MRCP) to assess for duct involvement, and more recently, positron emission tomography (PET) imaging to assess for extra-pancreatic sites of involvement. While the imaging appearance of AIP varies widely, certain imaging features are more likely to represent AIP than alternate diagnoses, such as pancreatic cancer. While nonspecific, imaging findings which favor a diagnosis of AIP rather than pancreatic cancer include: delayed enhancement of affected pancreas, mild dilatation of the main pancreatic duct over a long segment, the “capsule” and “penetrating duct” signs, and responsiveness to corticosteroid therapy. Systemic, extra-pancreatic sites of involvement are also often seen in AIP and IgG4-related disease, and typically respond to corticosteroid therapy. Imaging by CT, MR, and PET also play a role in the diagnosis and monitoring after treatment of involved sites.

Multifocal lesions with pancreatic atrophy in IgG4-related autoimmune pancreatitis: report of a case

We herein report a case of IgG4-related autoimmune pancreatitis (AIP). A 72-year-old male with jaundice visited our hospital complaining of epigastralgia. A blood chemistry analysis revealed elevated serum levels of total bilirubin and DUPAN-II. Computed tomography (CT) revealed irregularly shaped pancreatic masses with a stricture of the main pancreatic duct (MPD) in the head and tail that were interposed by marked atrophy with MPD dilation in the body. F-18 fluorodeoxyglucose (FDG)-positron emission tomography/CT revealed abnormally intense FDG uptake only at the masses. During surgery, another small tumor was also found in the atrophied body; therefore, a total pancreatectomy was performed under the diagnosis of multiple pancreatic cancers. The histological analysis revealed fibrosis with dense and diffuse infiltrations of lymphocytes and IgG4-positive plasma cells. The pancreatic parenchyma of the body was firmly replaced by fibrosis. AIP can lead to the formation of multiple pancreatic lesions, and thus the correct diagnosis is occasionally difficult to establish in atypical cases.

Positron emission tomography in malignancies of the liver, pancreas and biliary tract - indications and potential pitfalls

Abstract Malignancies of the hepato-pancreatico-biliary (HPB) system are relatively common and generally characterized by a dismal prognosis. Positron emission tomography (PET) is a functional imaging technique that has emerged as an important modality in oncological decision-making. The principal radiopharmaceutical in PET imaging is the glucose analog (18)F-fluorodeoxyglucose, which is able to detect altered glucose metabolism in malignant tissue. PET is typically used in conjunction with computed tomography (CT), and previous studies have supported several uses of PET/CT in HPB malignancies, including staging, differential diagnostics and monitoring of treatment response and progress of disease. A review of PET/CT in the context of HPB malignancies will be presented, including indications and potential pitfalls.

Type 1 autoimmune pancreatitis

Before the concept of autoimmune pancreatitis (AIP) was established, this form of pancreatitis had been recognized as lymphoplasmacytic sclerosing pancreatitis or non-alcoholic duct destructive chronic pancreatitis based on unique histological features. With the discovery in 2001 that serum IgG4 concentrations are specifically elevated in AIP patients, this emerging entity has been more widely accepted. Classical cases of AIP are now called type 1 as another distinct subtype (type 2 AIP) has been identified. Type 1 AIP, which accounts for 2% of chronic pancreatitis cases, predominantly affects adult males. Patients usually present with obstructive jaundice due to enlargement of the pancreatic head or thickening of the lower bile duct wall. Pancreatic cancer is the leading differential diagnosis for which serological, imaging, and histological examinations need to be considered. Serologically, an elevated level of IgG4 is the most sensitive and specific finding. Imaging features include irregular narrowing of the pancreatic duct, diffuse or focal enlargement of the pancreas, a peri-pancreatic capsule-like rim, and enhancement at the late phase of contrast-enhanced images. Biopsy or surgical specimens show diffuse lymphoplasmacytic infiltration containing many IgG4⁺ plasma cells, storiform fibrosis, and obliterative phlebitis. A dramatic response to steroid therapy is another characteristic, and serological or radiological effects are normally identified within the first 2 or 3 weeks. Type 1 AIP is estimated as a pancreatic manifestation of systemic IgG4-related disease based on the fact that synchronous or metachronous lesions can develop in multiple organs (e.g. bile duct, salivary/lacrimal glands, retroperitoneum, artery, lung, and kidney) and those lesions are histologically identical irrespective of the organ of origin. Several potential autoantigens have been identified so far. A Th2-dominant immune reaction and the activation of regulatory T-cells are assumed to be involved in the underlying immune reaction. IgG4 antibodies have two unique biological functions, Fab-arm exchange and a rheumatoid factor-like activity, both of which may play immune-defensive roles. However, the exact role of IgG4 in this disease still remains to be clarified. It seems important to recognize this unique entity given that the disease is treatable with steroids.

Autoimmune pancreatitis exhibiting multiple mass lesions

Our case is a first report of autoimmune pancreatitis with multiple masses within the pancreas which was pathologically diagnosed by endoscopic ultrasound-guided fine needle aspiration and treated by steroid. The masses disappeared by steroid therapy. Our case is informative to know that autoimmune pancreatitis sometimes exhibits multiple masses within the pancreas and to diagnose it without unnecessary surgery.

Small nodules which could indicate the early phase of autoimmune pancreatitis

We present a case with small pancreatic nodules, which could indicate the early phase of autoimmune pancreatitis (AIP). A 68-year-old man was referred to our hospital for further diagnostic evaluation of a pancreatic mass detected on abdominal ultrasonography screening for epigastric discomfort. Abdominal ultrasonography and endoscopic ultrasonography revealed a low echoic lesion measuring approximately 1 cm with an irregular margin in the body of the pancreas. Computed tomography revealed a tumor in the portal venous phase of enhancement; hence, a distal pancreatectomy was performed. On histology, a marked lymphocyte- and plasma cell-dominant inflammatory cell infiltrate was observed in the nodule. There was another smaller nodule consisting of moderate lymphoplasmacytic infiltration in the 2-cm distal portion of the pancreas. Lymphoplasmacytic infiltration was also observed around the main pancreatic duct in the pancreatic stump. In the parenchyma, other than these 3 portions, the normal lobular structure was well preserved. Little storiform fibrosis and obliterative phlebitis were observed in the resected specimen. On immunohistochemical staining, plasma cells showing strong immunoreactivity for immunoglobulin G4 were observed within these two nodules and around the main pancreatic duct at the cut surface. This case could indicate the early phase and multicentricity of AIP.

Adenocarcinoma involving the whole pancreas with multiple pancreatic masses

A 77-year-old man was referred to our hospital for further investigation of pancreatic masses. Imaging studies revealed hypovascular masses in the pancreatic head and body. Total pancreatectomy was performed under the diagnosis of double primary pancreatic carcinomas. Macroscopic examination revealed 3 nodules: one each in the pancreatic head, body, and tail. Microscopically, all 3 lesions showed similar carcinoma cells, which communicated with each other via the intraductal component, indicating a single large tumor. Incidentally, we also identified an adenocarcinoma of the common bile duct (CBD). The final diagnosis was synchronous double cancer involving the whole pancreas and the CBD.