Evaluation and management of cystic pancreatic tumors: emphasis on the role of EUS FNA.

Cystic lesions of the pancreas are increasingly recognized and usually represent pseudocysts or cystic pancreatic tumors (CPTs), but also include congenital cysts, acquired cysts, extrapancreatic cysts, or cystic degeneration of solid tumors. It is important to distinguish CPT lesions given their varied prognosis and therapy. Mucinous varieties of CPTs (mucinous cystic neoplasms and intraductal papillary mucinous tumors) are premalignant or malignant, and surgical resection is generally recommended in good operative candidates. In contrast, nonmucinous CPTs include serous cystadenomas with a very low malignant potential, or pseudocysts, which are always benign. As a result, nonmucinous CPTs are generally resected only when inducing symptoms or complications. Review of the clinical, imaging, laboratory, and pathology information may clarify the specific tumor type. The relatively limited accuracy of any one modality requires that we consider the combined results when making management decisions.     

Cystic lesions in the pancreas: When to watch, when to resect

The diagnosis of cystic lesions in the pancreas is becoming more common, largely due to the increases in diagnostic imaging done for other reasons. This review considers pseudocysts, mucinous cystic neoplasms, intraductal papillary mucinous tumors, and serous cystadenomas in some detail. The emphasis is on the fact that, through a careful history, physical examination, radiologic studies, and, often, cyst fluid analysis, a diagnosis can be reached expeditiously. This pursuit is important because two thirds of pancreatic cystic neoplasms are malignant or premalignant and should be resected, whereas pseudocysts and serous cystadenomas are benign, and, depending on the case, may be treated through observation, resection, or, for pseudocysts, by internal drainage.     

Management of the rare entity of primary pancreatic cystic neoplasms

Primary cystic neoplasms of the pancreas constitute a rare entity and are composed of a variety of neoplasms with a wide range of malignant potential. Approximately 90% of these lesions are serous cystic neoplasms or mucin-producing neoplasms. In contrast to serous cystadenomas which are nearly always benign, the mucinous cystic neoplasms represent a more diverse, heterogenous spectrum of related neoplasms. Intraductal papillary mucinous neoplasms manifest a much greater latent or overt malignant potential than other cystic neoplasms of the pancreas. The various subgroups of cystic neoplasms of the pancreas are evaluated and compared through a review of current literature. No symptoms or signs are pathognomonic for the cystic pancreatic neoplasms. While identification of a cystic tumor is relatively easy, the identification of the specific tumor type may be difficult. Most investigators agree that accurate differentiation of benign from malignant neoplasms can be made only at histopathologic examination of the entire resected segment of the pancreas. Because of the low mortality and low postoperative morbidity, surgical resection is indicated in all patients with cystic tumors.     

Resektion zystischer Pankreastumoren

Cystic tumors of the pancreas are diagnosed increasingly more due to increasing life expectancy and the moderate use of modern radiological diagnostics. Intraductal papillary mucinous neoplasms of the pancreas (IPMN), mucinous cystic neoplasms (MCN), solid pseudopapillary neoplasms (SPN) and serous cystic neoplasms (SCN) represent over 90?% of all cystic neoplasms of the pancreas. Although serous cystic lesions have a low or even no potential for malignant transformation, they are mostly resected when symptomatic. In contrast, mucinous lesions have an increased malignant potential and should therefore be resected in almost all cases. While this is true for all cases of MCNs and SPNs this is controversial for all IPMNs as they show a wide spectrum of morphological variants. The IPMNs may arise in the main pancreatic duct, major side branches or in both (mixed type). Although all IPMNs are considered to be precursor lesions to pancreatic adenocarcinomas it is not clear what the time course of such potential neoplastic transformation might be and whether all lesions progress to malignant tumors. As no currently used diagnostic test can reliably differentiate between benign and malignant tumors, the majority of newly diagnosed IPMNs should undergo surgical resection. According to current treatment guidelines (Sendai criteria), asymptomatic side branch IPMNs of less than 3 cm in diameter without suspicious radiological features, such as nodules, thickness of the cystic wall or size progression can be treated conservatively without the need for surgical resection. Recently, this approach has become controversial due to a relevant number of IPMNs reported as Sendai negative that showed malignant transformation on final histological examination.     

Pancreatic Cysts and Guidelines

Pancreatic cysts, especially incidental asymptomatic ones seen on noninvasive imaging such as CT or MR imaging, remain a clinical challenge. The etiology of such cysts may range from benign cysts without any malignant potential such as pancreatic pseudocysts and serous cystadenomas to premalignant or frankly malignant cysts such as mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, cystic degeneration associated with solid tumors such as pancreatic ductal adenocarcinoma or pancreatic endocrine neoplasms, and solid pseudopapillary neoplasms. The clinical challenge in 2017 is to accurately preoperatively diagnose them and their malignant potential before deciding about surgery, surveillance or doing nothing. This review will focus on the currently available clinical guidelines for doing so.     

Two cases of pancreatic ductal adenocarcinoma, manifested as solid pseudopapillary tumor and intraductal papillary mucinous neoplasm]

Compared with other types of cancers, pancreatic cancer is one of the most dreadful malignancies and is fifth leading cause of cancer-related death in Korea. It is difficult to expect early diagnosis or improvement in prognosis due to lack of specific early symptoms and effective diagnostic methods. Whereas cystic neoplasm of the pancreas is a rare type of pancreatic tumor, surgical resection provides good prognosis because of its low possibility of local invasion or distant metastasis. In case of pancreatic cystic tumor, radiologic differentiation between benign and malignant lesions is crucial for the selection of appropriate treatment and the prediction of prognosis. And ductal adenocarcinoma of pancreas presenting in cystic form is an uncommon type of cystic tumor, making it extremely rare among all pancreatic malignancies. We report two cases of atypical pancreatic ductal adenocarcinoma presenting as solid pseudopapillary tumor and intraductal papillary mucinous neoplasm, respectively.     

Zystische Pankreasl?sionen

Cystic changes of the pancreas comprise a large spectrum of neoplastic and non-neoplastic lesions. Among these are five entities, i.e. pseudocysts, intraductal papillary mucinous neoplasms (IPMN), mucinous cystic neoplasms (MCN), serous cystic neoplasms (SCN) and solid pseudopapillary neoplasms (SPN), which represent 95% of all cystic pancreatic lesions. While SCN and SPN have a good prognosis, IPMN and MCN have a high risk of malignancy as they are potential precursors of pancreatic ductal adenocarcinoma. The differential diagnosis between these five entities is based on epidemiology, pathology and clinical criteria. Consideration of these criteria allows in many cases a preoperative stratification that is the basis for an adequate therapy.     

Magnetic resonance imaging in the detection of pancreatic neoplasms

Recently, with the rapid scanning time and improved image quality, outstanding advances in magnetic resonance (MR) methods have resulted in an increase in the use of MRI for patients with a variety of pancreatic neoplasms. MR multi-imaging protocol, which includes MR cross-sectional imaging, MR cholangiopancreatography and dynamic contrast-enhanced MR angiography, integrates the advantages of various special imaging techniques. The non-invasive all-in-one MR multi-imaging techniques may provide the comprehensive information needed for the preoperative diagnosis and evaluation of pancreatic neoplasms. Pancreatic neoplasms include primary tumors and pancreatic metastases. Primary tumors of the pancreas may be mainly classified as ductal adenocarcinomas, cystic tumors and islet cell tumors (ICT). Pancreatic adenocarcinomas can be diagnosed in a MRI study depending on direct evidence or both direct and indirect evidence. The combined MRI features of a focal pancreatic mass, pancreatic duct dilatation and parenchymal atrophy are highly suggestive of a ductal adenocarcinoma. Most cystic neoplasms of the pancreas are either microcystic adenomas or mucinous cystic neoplasms. Intraductal papillary mucinous tumors are the uncommon low-grade malignancy of the pancreatic duct. ICT are rare neoplasms arising from neuroendocrine cells in the pancreas or the periampullary region. ICT are classified as functioning and non-functioning. The most frequent tumors to metastasize to the pancreas are cancers of the breast, lung, kidney and melanoma. The majority of metastases present as large solitary masses with well-defined margins.     

Clinicopathologic review of 41 cases of pancreatic mucinous cystic neoplasms]

BACKGROUND/AIMS: Intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms are included in mucin-producing pancreatic tumors. The reports about IPMN are not uncommon but those about the mucinous cystic neoplasms are relatively few. The aims of this study were to define the natural history of resected mucinous cystic neoplasms of the pancreas and to identify the findings which suggest malignancy. METHODS: The authors retrospectively evaluated the clinical outcomes of 41 patients with mucinous cystic neoplasms who were surgically resected at Asan Medical Center between 1995 and 2004. RESULTS: Women (n=33) were more frequently affected than men (n=8). Thirty three patients (80.6%) had adenoma, 1 (2.4%) borderline malignancy, 1 (2.4%) carcinoma in situ, and 6 (14.6%) invasive mucinous cystadenocarcinoma. The most frequent symptom was abdominal pain (39%). About half of the enrolled patients were asymptomatic. Unilocular type (79%) was more frequent than the multilocular type (21%) on gross morphology. The tumor size of invasive mucinous cystic neopolasms was larger than that of non-invasive mucinous cystic neoplalsms (p=0.01). Abdominal pain was more frequent in invasive mucinous cystic neoplasms (p=0.026). On gross morphology, mural nodules were detected in 4 of 6 patients with invasive mucinous cystic neoplasms. However, they were not detected in any patients with non-invasive mucinous cystic neoplasms. Recurrence developed in none of the 35 patients with non-invasive mucinous cystic neoplasms, however 2 of the 6 patients with invasive mucinous cystic neoplasms died within 5 years. CONCLUSIONS: Clinical predictors of invasive mucinous cystic neoplasms are suggested to be tumor size and abdominal pain. The prognosis of the non-invasive mucinous cystic neoplasms is excellent when curative resection is performed.     

Cystic neoplasms of the pancreas: a series.

MATERIAL AND METHODS: a series of 23 cases with cystic pancreatic neoplasms studied and treated between December 1977 and December 2001 out of 297 cases of pancreatic neoplasms is presented. RESULTS: 16/23 were true pancreatic cystic neoplasms: 9 microcystic adenomas and 6 mucinous cystoadenoma type. There were also 2 hydatid cysts, 1 lymphangioma, 2 cases of tuberculosis involving de pancreas, 1 lymphoma and 1 papillary cystic tumor type. CONCLUSIONS: true cystic tumors of the pancreas accounts for 5,8% of the neoplasms studied in our hospital.     

Multifocal intraductal papillary mucinous neoplasm of the pancreas-A case report

Cystic neoplasms of the pancreas are relatively rare, comprising 10 percent of pancreatic cysts and only 1 percent of pancreatic cancers. Cystic neoplasms include mucinous cystic neoplasms, serous cystadenomas, papillary cystic tumors, cystic islet cell tumors and intraductal papillary mucinous neoplasms of the pancreas （IPMNs）. IPMN was first described in 1982. It has been most commonly described in 60 to 70 years old males, and represents a relatively ＂new＂ but increasingly recognized disease. The improvement and widespread use of modern imaging equipments and heightened awareness of physicians contribute to the increasing incidence of IPMN. The majority of IPMNs are located in the pancreatic head （75%） while the rest involves the body/tail regions. Multifocal IPMNs have been hypothesized, but the true presence of multifocality is unknown. Here we present a 72-year- old male diagnosed with IPMN （carcinoma in situ） in the pancreatic head and a branch duct type IPMN （duct atypia） in the pancreatic body and tail. The patient underwent a Whipple intervention and a distal pancreatectomy. A three-year disease-free survival has been observed so far.     

Intraductal papillary mucinous tumors of the pancreas

Cystic neoplasms of the exocrine pancreas are a small fraction of pancreatic tumors. Within that group of cystic neoplasms, intraductal papillary mucinous tumors (IPMTs) can be distinguished from mucinous cystic neoplasms, serous cystic neoplasms, and pseudopapillary cystic tumors. Awareness of IPMTs has increased since the World Health Organization classified these tumors as its own group in 1996. Because of their favorable prognosis, an extensive diagnostic workup for IPMTs should be performed in patients presenting with cystic lesions of the pancreas. This workup often leads to the diagnosis and the predominant tumor location and size, although the extent of the ductal changes can only be established by histopathology. Surgical resection is the therapy of choice for IPMTs. The type of resection depends upon the extent of the quantitative and qualitative ductal involvement. Total pancreatectomy is currently the treatment for an IPMT that comprises the entire main duct.     

Intraductal papillary mucinous tumors and mucinous cystic tumors of the pancreas: imaging

Most cystic lesions of the pancreas are nonneoplastic and inflammatory in nature. However, approximately 5%–15% of cystic pancreatic masses may be neoplastic. Among the cystic neoplasms are the mucin-producing tumors, both the intraductal papillary mucinous neoplasms and the mucinous cystic neoplasms. Their imaging features on contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) can assist in the differentiation of these lesions. The imaging findings of both intraductal papillary mucinous neoplasm and mucinous cystic neoplasm are reviewed with attention to CT and MRI.     

Rare case of adult pancreatic hemangioma and review of the literature

Pancreatic hemangiomas are a rare type of cystic tumor, with very few cases reported in the literature. Herein, we present the case of a 28-year-old woman who was admitted to our hospital for abdominal pain. A physical examination failed to reveal any abnormalities that could explain her symptoms. A contrast-enhanced computed tomography showed a multilocular cyst with moderately enhanced septa and fluid-fluid levels in the body and tail of the pancreas. A serous cystadenoma or pseudocyst of the pancreas was initially suspected, and the patient underwent a subtotal pancreatectomy and splenectomy. The pathologic diagnosis was a pancreatic hemangioma. This is the second case of pancreatic hemangioma with fluid-fluid levels reported in the literature. Upon imaging, the presentation of this tumor can resemble serous or mucinous cystadenomas, pseudocysts of the pancreas, and side-branch type intraductal papillary mucinous neoplasms. This report reviews the clinical symptoms, radiologic features, pathologic characteristics, differential diagnoses, and treatment of this rare lesion type.     

Mucinous Cystadenoma: Pitfalls of Differential Diagnosis

Cystic neoplasms of the pancreas often are difficult to differentiate from pseudocysts. It has been proposed that a history of clinical pancreatitis, elevated serum pancreatic enzymes, elevated cyst fluid amylase, and a communication with the pancreatic duct suggest the diagnosis of a pseudocyst. We report the case of a young woman who presented with a cystic mass in the pancreas and was thought to have a pseudocyst because of the above; at surgery, a mucinous cystadenoma was documented. The pitfalls of differentiating neoplastic cysts of the pancreas from pseudocysts are discussed.     

Diagnostic dilemmas in patients with cystic neoplasms of the pancreas

Cystic neoplasms of the pancreas (CNP) are rare lesions that can be difficult to diagnose preoperatively. Twenty patients with cystic neoplasms of the pancreas including five microcystic adenomas, six benign mucinous cystic neoplasms, three malignant mucinous cystic neoplasms, two solid and papillary epithelial neoplasms, and four cystic neuroendocrine tumors were treated at a single institution between 1962 and 1987. The average duration of symptoms prior to diagnosis was 10 months. Five patients were asymptomatic. Forty percent of patients presented with an abdominal mass. Plain abdominal x-rays and UGI barium contrast studies were never diagnostic. Ultrasonography, computerized tomography (CT) and visceral angiography aided in the correct diagnosis in 28%, 36%, and 75% of patients studied, respectively. Overall a correct diagnosis was made preoperatively in only 35% of patients. Twelve of 13 patients were correctly diagnosed at laparotomy with intraoperative biopsy. Without biopsy the mass was misdiagnosed at laparotomy in five of six cases. CNP must be suspected in any patients who present with an upper abdominal mass with or without abdominal pain and no history of pancreatitis. CT may be diagnostic in up to one third of cases and should be obtained routinely to demonstrate the proximity of the lesion to other structures. Visceral angiography should also be obtained prior to operation. A generous incisional biopsy should be obtained of all pancreatic cysts that are not to be resected.     

EUS in the evaluation of pancreatic cystic lesions

BACKGROUND: The differential diagnosis in pancreatic cystic lesions is often difficult despite the availability of various modern imaging modalities. This study assessed the role of EUS in the following: (1) discrimination of pseudocysts from pancreatic cystic tumors, (2) differential diagnosis between serous cystadenoma and mucinous cystic tumor, and (3) prediction of accompanying malignancy in intraductal papillary mucinous tumor. METHODS: EUS findings in 75 patients with pancreatic cystic lesions (58 cystic tumors, 17 pseudocysts) were evaluated. In the comparison of pseudocysts and cystic tumors, the latter included intraductal papillary mucinous tumor, mucinous cystic tumors, and serous cystadenomas, but not solid-pseudopapillary tumors. RESULTS: In univariate analysis, pseudocysts exhibited echogenic debris and parenchymal changes more often than cystic tumors did (respectively, 29% vs. 6%, p < 0.05; and 65% vs. 4%, p < 0.001). In contrast, septa and mural nodules were found more frequently in cystic tumors than pseudocysts (respectively, 69% vs. 12%, p < 0.001; 56% vs. 12%, p < 0.01). Multivariate analysis revealed that parenchymal changes (odds ratio [OR] = 83.59; p < 0.01); septa (OR = 30.75; p < 0.05); and mural nodules (OR = 21.38; p < 0.05) were independent predictors of differentiation between pseudocysts and cystic tumors. Serous cystadenoma exhibited diverse EUS features, as well as a honeycomb appearance. Mural nodules were found more often in mucinous cystic tumors than in serous cystadenomas (p < 0.05). There were no factors that predicted malignancy in intraductal papillary mucinous tumor. CONCLUSIONS: EUS is a useful complementary imaging method for differentiation of pancreatic cystic lesions.     

Serous cystic neoplasm of the pancreas-indications for surgery

BACKGROUND/AIMS: Serous cystic neoplasm is a rare pancreatic tumor. Almost all of these tumors are benign and only 9 cases of serous cystadenocarcinoma have been reported. Although serous cystic neoplasm is typically a microcystic lesion, there is a wide range of cyst sizes from micro to macro and even unilocular cysts have been reported. Thus, the diagnosis is difficult and indications for surgery are controversial. We aimed to elucidate the clinicopathological and imaging features of serous cystic neoplasm of the pancreas. METHODOLOGY: We investigated 15 cases of resected and 6 cases of nonresected cases of serous cystic neoplasm, evaluating the symptoms, imaging findings, preoperative diagnosis, macroscopic morphology, microscopic findings, and results of follow-up. RESULTS: Imaging diagnosis of serous cystic neoplasm was not easy, because not so many tumors had the typical microcystic pattern. Most of the resected serous cystic neoplasms were non-microcystic or were small tumors, which could not be precisely evaluated. CONCLUSIONS: Small serous cystic neoplasms, which can be diagnosed by imaging, do not need to be resected because serous cystadenocarcinoma is rare. Tumors of the pancreas that cannot be confirmed to be serous cystic neoplasm should be resected because of the possibility of pancreatic cancer, mucinous cystadenocarcinoma, or mucinous cystadenoma with malignant potential.     

Diagnostic dilemmas in patients with cystic neoplasms of the pancreas

Summary Cystic neoplasms of the pancreas (CNP) are rare lesions that can be difficult to diagnose preoperatively. Twenty patients with cystic neoplasms of the pancreas including five microcystic adenomas, six benign mucinous cystic neoplasms, three malignant mucinous cystic neoplasms, two solid and papillary epithelial neoplasms, and four cystic neuroendocrine tumors were treated at a single institution between 1962 and 1987. The average duration of symptoms prior to diagnosis was 10 months. Five patients were asymptomatic. Forty percent of patients presented with an abdominal mass. Plain abdominal x-rays and UGI barium contrast studies were never diagnostic. Ultrasonography, computerized tomography (CT) and visceral angiography aided in the correct diagnosis in 28%, 36%, and 75% of patients studied, respectively. Overall a correct diagnosis was made preoperatively in only 35% of patients. Twelve of 13 patients were correctly diagnosed at laparotomy with intraoperative biopsy. Without biopsy the mass was misdiagnosed at laparotomy in five of six cases. CNP must be suspected inany patients who present with an upper abdominal mass with or without abdominal pain and no history of pancreatitis. CT may be diagnostic in up to one third of cases and should be obtained routinely to demonstrate the proximity of the lesion to other structures. Visceral angiography should also be obtained prior to operation. A generous incisional biopsy should be obtained of all pancreatic cysts that are not to be resected.     

Update on the Molecular Pathogenesis of Pancreatic Tumors Other than Common Ductal Adenocarcinoma

Purpose: Although ductal adenocarcinoma is the most common and well known pancreatic tumor type, other distinct epithelial neoplasms affecting the pancreas that show different symptoms, biological behaviors and outcomes are becoming more frequently recognized and documented. Pancreatic epithelial tumors may be separated into ductal and nonductal neoplasms. The former group includes pancreatic ductal adenocarcinoma, intraductal papillary-mucinous tumor, mucinous cystic tumor and serous cystic tumor. The latter group includes pancreatic endocrine tumor, pancreatic acinar cell carcinoma, pancreatoblastoma and solid-pseudopapillary tumor. The aim of this review is to summarize recently acquired knowledge regarding the molecular characterization of these uncommon pancreatic epithelial neoplasms. Recent Findings: Molecular studies of uncommon pancreatic epithelial tumors suggest that the different morphological entities are associated with distinct molecular profiles, highlighting the involvement of different molecular pathways leading to the development of each subtype of pancreatic neoplasm. Conclusion: The correct classification of rare pancreatic epithelial tumors and the identification of their characteristic molecular aspects is the fundamental starting point in identifying novel diagnostic molecular tools and new targets for innovative therapeutic Strategies.