Clinicopathological features and prognosis of mucinous cystic neoplasm with ovarian-type stroma: a multi-institutional study of the Japan pancreas society

Mucinous cystic neoplasms of the pancreas associated with pregnancy: Two case reports

RATIONALE

Although rare, pancreatic neoplasms can occur during pregnancy, both in benign and malignant forms. Mucinous cystic neoplasms (MCNs) of the pancreas, a type of these neoplasms, are precursor lesions to invasive pancreatic cancer. The presence of the ovarian-type stroma is a defining feature.

PATIENT CONCERNS

The first case was a 38-year-old woman in her 18th week of pregnancy with abdominal pain that worsens a few weeks later. The second case was a 30-year-old woman in her 17th week of pregnancy with abdominal pain in the left hypochondrium.

DIAGNOSIS

The patients were under clinical examination and laboratory test including carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA). Both patients had magnetic resonance imaging (MRI). The diagnosis of a MCNs of the pancreas was done preoperatively in the 2 cases.

INTERVENTIONS

Both patients underwent distal pancreatectomy during pregnancy. One of them was an emergency laparotomy because of a ruptured MCN.

OUTCOMES

Both patients were completely recovered from distal pancreatectomy and continued to full term, delivering a healthy baby by Caesarean section. After 6 years of follow-up, the first patient underwent a total gastrectomy, because of a gastric cancer with carcinomatosis. Currently the 2 patients are still alive after 8 years and 5 years of follow-up, respectively.

LESSONS

Surgical resection of MCNs during pregnancy should be considered during the second trimester given common distal pancreas location, rapid growth, risk of spontaneous rupture, and malignant potential.

Endoscopic ultrasonography for the evaluation of pancreatic cystic neoplasms

Endoscopic ultrasonography (EUS) is a modality with high spatial resolution that enables comprehensive observation of the entire pancreas and plays an important role in the diagnosis of pancreatic lesions. Recent advances in diagnostic imaging methods such as ultrasound, computed tomography, and magnetic resonance imaging have increased the incidental detection of pancreatic cystic lesions (PCLs). EUS has been recognized as an essential diagnostic method for the detection and evaluation of PCLs. EUS has two important roles: as a detailed (high-resolution) imaging diagnostic method and as an approach for collecting cyst fluid content by EUS-guided fine needle aspiration for pathological diagnosis or biomarker evaluation. Furthermore, in recent years, the usefulness of contrast-enhanced EUS for the differential diagnosis of PCLs or evaluation of grade of malignancy, and a novel imaging technique called needle-based confocal laser endomicroscopy to observe intraductal structures through a needle, has been reported. An understanding of the morphological characteristics of PCLs depicted by ultrasound imaging and of the benefits and limitations of EUS diagnosis in daily practice is needed.

A case of ruptured mucinous cystadenoma of the pancreas with recurrence-free survival for 8 years

BACKGROUND

Pancreatic mucinous cystic neoplasm (MCM) presenting with rupture is extremely rare, and very few studies have followed up patients over the long term after ruptured mucinous cystadenoma (MCA). We report a case of ruptured MCA of the pancreas with recurrence-free survival for 8 years.

CASE PRESENTATION

A 28-year-old Japanese woman was admitted to the emergency department of a local hospital after experiencing acute abdominal pain. Abdominal computed tomography revealed massive ascites and the presence of a cystic tumor measuring 60 mm in diameter in the pancreatic tail. Conservative therapy with antibiotics and abdominal drainage were performed to treat peritonitis that occurred secondary to the ruptured pancreatic cystic tumor, after which the patient's symptoms improved. The patient was referred to our department for further examination and treatment. We diagnosed a ruptured MCN and performed laparoscopic spleen-preserving distal pancreatectomy. Histopathological findings revealed ovarian-type stroma, which tested positive for estrogen and progesterone receptors by immunohistochemistry. The histopathological diagnosis was MCA. The postoperative course was uneventful, and the patient remains alive without any evidence of recurrence at 8 years postoperatively.

CONCLUSION

A good prognosis is possible even in cases of ruptured MCA. Because of the risk of peritoneal dissemination after ruptured MCA, long-term follow-up is important.

A Contrast-Enhanced Computed Tomography Based Radiomics Approach for Preoperative Differentiation of Pancreatic Cystic Neoplasm Subtypes: A Feasibility Study

Background: Serous cystadenoma (SCA), mucinous cystadenoma (MCN), and intraductal papillary mucinous neoplasm (IPMN) are three subtypes of pancreatic cystic neoplasm (PCN). Due to the potential of malignant-transforming, patients with MCN and IPMN require radical surgery while patients with SCA need periodic surveillance. However, accurate pre-surgery diagnosis between SCA, MCN, and IPMN remains challenging in the clinic. Methods: This study enrolled 164 patients including 76 with SCA, 40 with MCN and 48 with IPMN. Patients were randomly split into a training cohort (n = 115) and validation cohort (n = 41). We performed statistical analysis and Boruta method to screen significantly distinct clinical factors and radiomics features extracted on pre-surgery contrast-enhanced computed tomography (CECT) images among three subtypes. Three reliable machine-learning algorithms, support vector machine (SVM), random forest (RF) and artificial neural network (ANN), were utilized to construct classifiers based on important radiomics features and clinical parameters. Precision, recall, and F1-score were calculated to assess the performance of the constructed classifiers. Results: Nine of 547 radiomics features and eight clinical factors showed a significant difference among SCA, MCN, and IPMN. Five radiomics features (Histogram_Entropy, Histogram_Skeweness, LLL_GLSZM_GLV, Histogram_Uniformity, HHL_Histogram_Kurtosis), and four clinical factors, including serum carbohydrate antigen 19-9, sex, age, and serum carcinoembryonic antigen, were identified important by Boruta method. The SVM classifier achieved an overall accuracy of 73.04% in training cohort and 71.43% in validation cohort, respectively. The RF classifier achieved overall accuracy of 84.35 and 79.59%, respectively. The constructed ANN model showed an overall accuracy of 77.39% in the training dataset and 71.43% in the validation dataset. All the three classifiers showed high F1 score for differentiation among the three subtypes. Conclusion: Our study proved the feasibility and translational value of CECT-based radiomics classifiers for differentiation among SCA, MCN, and IPMN.

Prediction of the Probability of Malignancy in Mucinous Cystic Neoplasm of the Pancreas With Ovarian-Type Stroma: A Nationwide Multicenter Study in Japan

OBJECTIVE

The aim of the study was to develop a formula for predicting the probability of malignancy of mucinous cystic neoplasm (MCN) of the pancreas with ovarian-type stroma.

METHODS

A total of 364 patients were enrolled. A total score was calculated as the sum of the approximate integers of the odds ratios of the predictive factors identified by multivariate analysis. The relationship between the total score and pathological results was assessed.

RESULTS

A total of 321 patients had benign MCN and 43 had malignant MCN. Five possible predictive factors were analyzed: 56 years or older, high serum carcinoembryonic antigen level, high carbohydrate antigen 19-9 level, tumor size of 51 mm or greater, and the presence of mural nodules. The total score was significantly higher in patients with malignant MCN (median, 24; range, 0-37) compared with benign MCN (median, 5; range, 0-33; P < 0.001). Receiver operating characteristic curve analysis demonstrated that the area under the curve was 0.86, and the sensitivity and specificity of the total score for discriminating malignant MCNs were 72% and 83%, respectively, using a cut-off value of 22.

CONCLUSIONS

The current simple formula can predict the malignancy of MCN and may thus contribute to the adequate management of patients with MCN.

Mucinous Cystadenocarcinoma of the Pancreas with Cyst Infection in a Male Patient

Follow-up computed tomography revealed a 40-mm pancreatic tail cyst in a 59-year-old man with type 1 diabetes mellitus. An intraductal papillary mucinous neoplasm was suspected; mucinous cystic neoplasm (MCN) was not considered because the patient was a man. During follow-up, cyst infection occurred but was improved by conservative treatment. At the 24-month follow up examination, cyst nodules had developed, corresponding to an increase in the carbohydrate antigen 19-9 level. Mucinous cystadenocarcinoma (MCC) was diagnosed pathologically based on distal pancreatectomy. A diagnosis of male MCN/MCC is often delayed, which may lead to a poor prognosis. MCN infection is also rare and poorly recognized. We observed an atypical male case of MCN/MCC.

Preoperative differentiation of pancreatic mucinous cystic neoplasm from macrocystic serous cystic adenoma using radiomics: Preliminary findings and comparison with radiological model

PURPOSE

To develop a radiomics model in the preoperative differentiation of mucinous cystic neoplasm (MCN) and macrocystic serous cystadenoma (MaSCA) and to compare its diagnostic performance with conventional radiological model.

METHODS

57 Patients (MCN = 31, MaSCA = 26) with preoperative multidetector computed tomography (MDCT) scans were retrospectively included in this study. A radiological model was constructed from radiological features evaluated by radiologists. A radiomics model was constructed with high-dimensional quantitative features extracted from manually segmented volume of interests (VOIs). A combined model was constructed using both radiomics features and radiological features. The diagnostic performance of three models were assessed by the area under the receiver-operating characteristic curve (AUC), sensitivity, specificity, accuracy, and the calibration curves.

RESULTS

The radiological model yielded an AUC of 0.775, sensitivity of 74.2 %, specificity of 80.8, and accuracy of 77.2 %. The radiomics model yielded an AUC of 0.989, sensitivity of 93.6 %, specificity of 96.2 %, and accuracy of 94.7 %. The combined model yielded an AUC of 0.994, sensitivity of 96.8 %, specificity of 100 %, and accuracy of 98.2 %. Both combined model and radiomics model showed higher AUC, sensitivity, and accuracy than radiological model (all P <  .05). The combined model showed higher AUC than radiomics model, though no significant difference was found (P =  .41). The combined model showed better calibration than radiomics model (P =  .91 vs. P <  .001).

CONCLUSIONS

Combined model which contained both radiomics features and radiological features outperformed radiomics model and radiological model in the preoperative differentiation of MCN and MaSCA.

Two cases of non-mucinous cystadenomas of the pancreas with pancreatobiliary phenotype and ovarian-like stroma

BACKGROUND

Diagnosis of cystic tumor of the pancreas is based on the World Health Organization criteria that classify pancreatic cystadenomas into four types: intra-ductal papillary mucinous neoplasms, mucinous cystic neoplasms (MCNs), serous cystic neoplasms, and solid pseudo-papillary neoplasms depending on their secretion and presence of ovarian-like stroma. Recently, Albores-Saavedra identified non-mucinous cystadenomas of the pancreas with pancreato-biliary phenotype and ovarian-like stroma. This precipitated examination of the proportions of these rare tumors in patients treated at Tokushima University Hospital.

CASE PRESENTATION

Case 1 was a 40-year-old woman with a cystic tumor in the tail of the pancreas. Computed tomography (CT) revealed a diffuse and non-enhanced cystic tumor in the tail of the pancreas. This tumor was diagnosed as a simple cyst at this point. However, 2 years later, the tumor had increased in size by 3 cm. Thus, laparoscopic distal pancreatectomy was performed. The content of the cyst was serous. The epithelial cells were lined with a single layer of cuboidal cells and the tumor had ovarian-like stroma pathologically. The final pathological diagnosis was non-mucinous cystadenoma of the pancreas with ovarian-like stroma. In Case 2, a cystic tumor in the pancreas was found by medical examination in a woman in her sixties who presented without symptoms. CT showed a 1.5-cm cystic tumor in the tail and body of the pancreas and a septum in the cyst. Nine years later, the tumor had grown to 2.4 cm in diameter and had a clear septum in the cyst. This tumor was diagnosed preoperatively as MCN. Thus, laparoscopic distal pancreatectomy was performed. The cyst contained serous fluid. Microscopic examination showed no ovarian-like stroma and the epithelial cells were lined by a single layer of cuboidal cells. The final pathological diagnosis was non-mucinous cystadenoma of the pancreas with ovarian-like stroma.

CONCLUSIONS

Accurate preoperative diagnosis of this type of pancreatic cystic tumor may be difficult, although it occurs more often than expected. Non-mucinous cystadenomas of the pancreas with ovarian-like stroma need to be considered as a differential diagnosis.

Diagnosis and management of pancreatic cystic neoplasms

This review outlines the current classification of pancreatic cystic lesions, with a particular emphasis on pancreatic cystic neoplasms (PCNs). It will describe the diagnostic approach to PCNs, with reference to clinicopathological features, cross-sectional radiology and endoscopic ultrasound. This review will conclude with an evidence-based discussion of the management of PCNs focused on recent clinical guidelines.

A pancreatic mucinous cystic neoplasm undergoing intriguing morphological changes over time and associated with recurrent pancreatitis: A case report

RATIONALE

Mucinous cystic neoplasms (MCNs) are pancreatic mucin-producing cystic lesions with a distinctive ovarian-type stroma. The diagnosis is generally easy in typical cases; however, differential diagnosis is difficult in others such as in the case we report herein.

PATIENT CONCERNS

A 27-year-old woman with sudden onset of epigastric pain was referred to our hospital for suspected acute pancreatitis. Contrast-enhanced computed tomography revealed a 25-mm cystic lesion in the pancreas and a low density area with delayed enhancement at the right upper side of the cystic lesion.

DIAGNOSES

During its clinical course, the cystic lesion underwent various morphological changes. Eventually, it presented typical findings of MCNs, and could be accurately diagnosed.

INTERVENTIONS

Laparoscopic distal pancreatectomy was performed on the patient by preserving the spleen.

OUTCOMES

The patient revealed no symptoms till 1 year after the operation.

LESSONS

This case of MCN with intriguing short-term morphological changes was associated with recurrent pancreatitis. A combination of imaging modalities is essential for accurate diagnosis of MCNs, and follow-up with serial imaging might be useful for certain unusual lesions.

Diagnostic ability of artificial intelligence using deep learning analysis of cyst fluid in differentiating malignant from benign pancreatic cystic lesions

The diagnosis of pancreatic cystic lesions remains challenging. This study aimed to investigate the diagnostic ability of carcinoembryonic antigen (CEA), cytology, and artificial intelligence (AI) by deep learning using cyst fluid in differentiating malignant from benign cystic lesions. We retrospectively reviewed 85 patients who underwent pancreatic cyst fluid analysis of surgical specimens or endoscopic ultrasound-guided fine-needle aspiration specimens. AI using deep learning was used to construct a diagnostic algorithm. CEA, carbohydrate antigen 19-9, carbohydrate antigen 125, amylase in the cyst fluid, sex, cyst location, connection of the pancreatic duct and cyst, type of cyst, and cytology were keyed into the AI algorithm, and the malignant predictive value of the output was calculated. Area under receiver-operating characteristics curves for the diagnostic ability of malignant cystic lesions were 0.719 (CEA), 0.739 (cytology), and 0.966 (AI). In the diagnostic ability of malignant cystic lesions, sensitivity, specificity, and accuracy of AI were 95.7%, 91.9%, and 92.9%, respectively. AI sensitivity was higher than that of CEA (60.9%, p = 0.021) and cytology (47.8%, p = 0.001). AI accuracy was also higher than CEA (71.8%, p < 0.001) and cytology (85.9%, p = 0.210). AI may improve the diagnostic ability in differentiating malignant from benign pancreatic cystic lesions.

Age and cystic size are associated with clinical impact of endoscopic ultrasonography-guided fine-needle aspiration on the management of pancreatic cystic neoplasms

Objectives: The clinical impact of endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) in managing pancreatic cystic neoplasms (PCNs) remains controversial. The aim of this study was to identify which patients with PCNs would benefit from EUS-FNA. Methods: A retrospective study was performed on patients with PCNs who underwent EUS-FNA between January 2009 and June 2018. A discordant or a consistent diagnosis after EUS-FNA was analyzed and was correlated with the clinical demographic data and cystic features. Predictors of the change in the diagnosis after EUS-FNA were analyzed. Results: One hundred eighty-eight cases of PCNs were analyzed. EUS-FNA changed the diagnosis in 45.7% of all patients with PCNs and 54.5% patients with presumed branch ductal type intraductal papillary mucinous neoplasm (BD-IPMN) and impacted the recommendation in 35.6% of patients with PCNs and 50.5% patients with BD-IPMN. Patients with a discordant diagnosis after EUS-FNA were younger in age (54.8 ± 12.6 vs. 61.2 ± 14.2; p=.037) and had a cyst size larger than 3 cm than patients with a consistent diagnosis after EUS-FNA. The only worrisome feature (WF) that differed between patients with a discordant and a consistent diagnosis after EUS-FNA was the main pancreatic duct (MPD) between 5 and 9 mm (p=.013). In multivariate analysis, a cyst size >3 cm and age were independent predictors of diagnostic changes after EUS-FNA (OR: 5.33, 95% CI: 1.79-15.88, p = .003; OR: 0.96, 95% CI: 0.93-0.99, p  =  .031). Conclusions: EUS-FNA made a significant change in the management of nearly half of the patients with PCNs, especially in younger patients and in patients with a cyst size larger than 3 cm.

An osteoclast-like giant cell tumor embedded in the mural nodule of a pancreatic mucinous cystic neoplasm: A case report and literature review

RATIONALE

Mucinous cystic neoplasms (MCNs) are relatively rare lesions, accounting for 2%-5% of all exocrine pancreatic neoplasms. MCNs mainly occur in women (female:male ratio = 20:1), with a peak incidence in the 5th decade of life. Osteoclast-like giant cell tumors (OGCTs) are rare and relatively aggressive neoplasms, comprising <1% of all pancreatic carcinomas. Herein, we present a rare "combination tumor" case and discuss the impact of mural nodules in pancreatic MCNs considering malignant transformation.

PATIENT CONCERNS

A 54-year-old Mongolian man, without vomiting, nausea or jaundice, presented with abdominal distention since 3 months. He had a 7-year history of diabetes. Physical examinations indicated slight middle abdominal tenderness without rebound tenderness or rigidity. Laboratory results revealed that the level of carcinoembryonic antigen (CEA) was 1.16 ng/ml (normal: <5 ng/ml); CA-199: 30.02 U/ml (normal: <27 U/ml); hemoglobin: 143 g/L; fasting glucose: 7.71 mmol/L; and albumin: 43 g/L. Abdominal enhanced computed tomography revealed a 7 × 6 cm solid neoplasm in the pancreatic body with partial enhancement and heterogeneity. Endoscopic ultrasound revealed a solid-cystic space-occupying lesion in the pancreatic body.

DIAGNOSIS

The preoperative preliminary diagnosis was pancreatic solid-cystic tumor, possibly a solid pseudopapillary tumor. Postoperative pathological findings revealed a pancreatic borderline MCN with an OGCT embedded in a mural nodule of the capsule. Immunohistochemical results indicated a simultaneous dual origin from the epithelium and stroma.

INTERVENTIONS

The patient underwent open distal pancreatectomy and splenectomy. Postoperative blood glucose levels were closely monitored and regulated. We intravenously administered single-agent gemcitabine (1400 mg on day 1) as the first-time chemotherapy, 1 month after surgery. After the first chemotherapy, the patient refused to receive further treatment owing to personal reasons.

OUTCOMES

The patient showed uneventful recovery and was discharged 13 days after the initial surgery. Follow-up was performed 1, 3 and 6 months after surgery. At 6 months, abdominal computed tomography scan showed no signs of recurrence, regional lymphadenopathy, or other abnormalities. And laboratory tests showed a platelet count of 301 × 10/L, postprandial blood glucose of 12.9 mmol/L and CA-199 level of 20 U/ml. The patient had no obvious discomfort.

LESSONS

Although pancreatic MCNs are widely accepted as borderline tumors, malignant transformations may occur due to various risk factors (cyst size, mural nodules, septations, and tumor location). The combination tumor in this case was more likely to increase the possibility of malignant biological behavior, thereby worsening overall prognosis. Therefore, long-term follow-up must be maintained with strict monitoring.

Invasive Ductal Carcinoma Arising in Mucinous Cystic Neoplasm of Pancreas: A Case Report

BACKGROUND Mucinous cystic neoplasm (MCN) of the pancreas is a rare mucin-producing cystic neoplasm that has a characteristic histological feature referred to as ovarian-type stroma (OS) underlying the epithelium. Pancreatic ductal carcinoma arises from MCN as a precursor lesion, but data on progression pathways are limited. CASE REPORT A 40-year-old female was referred to our hospital for further investigation of a pancreatic cyst. Further examination showed a 7.0 cm multilocular cyst in the pancreatic tail and a solid mass in the thick septum of the cystic tumor. Distal pancreatectomy and splenectomy were performed. Histological examination revealed a moderately differentiated invasive ductal carcinoma (IDC) with a diameter of 0.5 cm in the thick septum of the cystic lesion and a cyst wall composed of epithelium with low-grade to severe dysplasia. The epithelium covered an OS. Pathological diagnosis was IDC arising in MCN of the pancreas. Immunohistochemical examination showed that MUC1 expression was negative in MCN but positive in IDC. KRAS mutation was observed in both MCN and IDC regions. CONCLUSIONS We present a rare case of moderately differentiated pancreatic IDC arising in MCN. To elucidate the underlying progression pathway, we explored the correlation between KRAS mutation and MUC expression as a clinicopathological parameter.

Current Approaches to Pancreatic Cancer Screening

Pancreatic ductal adenocarcinoma (PDAC) has a 5-year survival rate of only 8% and is estimated to be the second leading cause of cancer-related deaths by 2021. Prior convention held that screening for PDAC would not be beneficial; however, a deeper understanding of the carcinogenesis pathway supports a potential window of opportunity among the target population. Screening for PDAC is not a standard practice among the general population because of its low incidence. However, screening may be beneficial for individuals with familial history, chronic diseases with genetic predispositions, or inherited cancer syndromes, such as hereditary breast ovarian cancer syndrome, hereditary pancreatitis, Peutz-Jeghers syndrome, familial atypical multiple mole melanoma, Lynch syndrome (hereditary nonpolyposis colorectal cancer), ataxia telangiectasia, and Li-Fraumeni syndrome, all of which have been associated with an increased risk of developing PDAC. The screening strategies among these high-risk individuals are targeted to identify precursor lesions and PDAC at an early resectable stage. This review describes the risk factors for pancreatic cancer, especially the genetic risk factors in high-risk individuals and current screening strategies available for PDAC.

Pancreatic Cysts: Sinister Findings or Incidentalomas?

Pancreatic cysts are common and are incidentally detected in up to 13.5% of individuals. Intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm (MCN) are precursors to pancreatic adenocarcinoma. Most will never develop into pancreatic cancer. Several types of pancreatic cysts have no malignant potential. Solid tumors can present as a pancreatic cysts. Guidelines recommend surveillance. Management includes differentiating IPMNs and MCNs from other types, identifying those at highest risk of harboring pancreatic cancer or high-grade dysplasia, and referral to a multidisciplinary group for evaluation and consideration of surgical resection.

Risk of malignancy in resected pancreatic mucinous cystic neoplasms

BACKGROUND

Pancreatic mucinous cystic neoplasms (MCNs) are rare mucin-producing cystic tumours defined by the presence of ovarian-type stroma. MCNs have a malignant potential and thus surgery is frequently performed. The aim of this cohort study was to define better the criteria for surgical resection in patients with MCN.

METHODS

This multicentre retrospective study included all resected MCNs between 2003 and 2015 in participating centres. Lesions without ovarian-type stroma were excluded. Patient characteristics, preoperative findings, histopathology findings and follow-up data were recorded.

RESULTS

The study included 211 patients; their median age was 53 (range 18-82) years, and 202 (95·7 per cent) were women. Median preoperative tumour size was 55 (range 12-230) mm. Thirty-four of the 211 (16·1 per cent) were malignant, and high-grade dysplasia (HGD) was found in a further 13 (6·2 per cent). One-third of MCNs in men were associated with invasive cancer, compared with 15·3 per cent in women. Five cases of malignant transformation occurred in MCNs smaller than 4 cm. All cases of malignancy or HGD were associated with symptoms or features of concern on preoperative cross-sectional imaging. In multivariable analysis, raised carbohydrate antigen 19-9 (odds ratio (OR) 10·54, 95 per cent c.i. 2·85 to 218·23; P < 0·001), tumour size (OR 4·23, 3·02 to 11·03; P = 0·001), mural nodules (OR 3·55, 1·31 to 20·55; P = 0·002) and weight loss (OR 3·40, 2·34 to 12·34; P = 0·034) were independent factors predictive of malignant transformation.

CONCLUSIONS

Small indeterminate MCNs with no symptoms or features of concern may safely be observed as they have a low risk of malignant transformation.

Steroidogenesis in ovarian-like mesenchymal stroma of hepatic and pancreatic mucinous cystic neoplasms

Aim Mucinous cystic neoplasms (MCNs) occur in the ovary, pancreas, and retroperitoneum but very rarely in the liver. Mucinous cystic neoplasms are known to harbor ovarian-like mesenchymal stroma (OLS) expressing progesterone and estrogen receptors. In this study we evaluated steroidogenesis in OLS of 25 hepatic MCNs and 24 pancreatic MCNs. Methods Both steroid receptors and steroidogenic factors were immunohistochemically evaluated using H-scores and results were compared with those in 15 ovarian MCNs and 10 normal ovaries. Results Androgen receptor (AR) H-scores in OLS were significantly higher in hepatic, pancreatic, and ovarian MCN than those in normal ovaries. H-scores of cytochrome P450 17α-hydroxylase/c17-20 lyase (P450c17) and 5α-reductase-1 (5αRED-1) in the stroma were significantly higher in OLS of hepatic and pancreatic MCN than in the stroma of ovarian MCN and normal ovary. In tumor epithelium, AR H-scores were significantly higher in hepatic and pancreatic MCN than in ovarian MCN. In both hepatic and pancreatic MCN, a significant positive correlation was detected between AR H-score in the epithelium and P450c17 H-score in OLS (hepatic MCN: Pearson's r = 0.446, P = 0.025; pancreatic MCN: r = 0.432, P = 0.035). In pancreatic MCN, a significantly positive correlation was detected between AR H-score in the tumor epithelium and 5αRED-1 H-score in OLS (Pearson's r = 0.458, P = 0.024). Conclusions These results indicated that locally produced androgens in OLS could be pivotal for tumorigenesis of both hepatic and pancreatic MCN and influence epithelial cells, possibly in a paracrine fashion, which could represent biological significance of OLS in these neoplasms.

Primordial germ cells as a potential shared cell of origin for mucinous cystic neoplasms of the pancreas and mucinous ovarian tumors

Mucinous ovarian tumors (MOTs) morphologically and epidemiologically resemble mucinous cystic neoplasms (MCNs) of the pancreas, sharing a similar stroma and both occurring disproportionately among young females. Additionally, MOTs and MCNs share similar clinical characteristics and immunohistochemical phenotypes. Exome sequencing has revealed frequent recurrent mutations in KRAS and RNF43 in both MOTs and MCNs. The cell of origin for these tumors remains unclear, but MOTs sometimes arise in the context of mature cystic teratomas and other primordial germ cell (PGC) tumors. We undertook the present study to investigate whether non-teratoma-associated MOTs and MCNs share a common cell of origin. Comparisons of the gene expression profiles of MOTs [including both the mucinous borderline ovarian tumors (MBOTs) and invasive mucinous ovarian carcinomas (MOCs)], high-grade serous ovarian carcinomas, ovarian surface epithelium, Fallopian tube epithelium, normal pancreatic tissue, pancreatic duct adenocarcinomas, MCNs, and single-cell RNA-sequencing of PGCs revealed that both MOTs and MCNs are more closely related to PGCs than to either eutopic epithelial tumors or normal epithelia. We hypothesize that MCNs may arise from PGCs that stopped in the dorsal pancreas during their descent to the gonads during early human embryogenesis, while MOTs arise from PGCs in the ovary. Together, these data suggest a common pathway for the development of MCNs and MOTs, and suggest that these tumors may be more properly classified as germ cell tumor variants. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Genetics of Pancreatic Neoplasms and Role of Screening

There is a wide spectrum of pancreatic neoplasms with characteristic genetic abnormalities, tumor pathways, and histopathology that primarily determine tumor biology, treatment response, and prognosis. Although most pancreatic tumors are sporadic, 10% of neoplasms occur in the setting of distinct hereditary syndromes. Detailed studies of these rare syndromes have allowed researchers to identify a myriad of specific genetic signatures of pancreatic tumors. A better understanding of tumor genomics may have significant clinical implications in the diagnosis and management of patients with pancreatic tumors. Evolving knowledge has paved the way to screening paradigms and protocols in individuals at higher risk of developing pancreatic tumors.

Cholangiocarcinoma

This article focuses on cholangiocarcinoma, both intrahepatic and extrahepatic. The various classification schemes based on anatomic location, macroscopic growth pattern, microscopic features, and cell of origin are outlined. The clinicopathologic, immunohistochemical and molecular differences between intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma, as well as differences in the 2 subtypes of intrahepatic cholangiocarcinoma, are discussed. Finally, precursor lesions, prognosis, treatment, and promising new potential targeted therapies are reviewed.

Significance of T1a and T1b Carcinoma Arising in Mucinous Cystic Neoplasm of Pancreas

Mucinous cystic neoplasm (MCN) of pancreas is one of the precursor lesions of pancreatic ductal adenocarcinoma. The 5-year disease-specific survival for noninvasive MCNs was 100% and 20% to 60% for those with pancreatic ductal adenocarcinoma arising in a MCN. However, the significance of T1a (≤0.5 cm) and T1b (>0.5 and <1.0 cm) carcinoma arising in MCN as defined by the upcoming American Joint Committee on Cancer, eighth edition is unclear. In this study, we examined 3 cases of MCN with T1a or T1b carcinoma and compared their clinicopathologic characteristics and survival to 46 cases of MCN with low-grade dysplasia (MCN-LGD), 7 cases of MCN with high-grade dysplasia (MCN-HGD), and 7 cases of MCN with advanced invasive carcinoma (T2 or higher T stage). The tumors from all 3 cases were submitted in their entirety in 123, 296, and 200 blocks, respectively. All 3 patients were alive with no recurrence during the follow-up of 20.0, 113.8, and 137.2 months, respectively. Similarly, none of the patients who had MCN with either LGD or HGD had recurrence or died of disease. In contrast, 5 of 7 patients who had MCN with advanced invasive carcinoma had recurrence and later died of disease with a median survival of 22.9 months (P<0.001). Our study showed that MCN with T1a and T1b carcinoma had an excellent prognosis similar to MCNs with LGD or HGD after complete tumor sampling for histologic examination. Our results along with the previous studies suggest that close follow-up, rather than aggressive systemic therapy, may be a better approach for these patients.

Analysis of Pancreatic Cyst Fluid

Pancreatic cysts are extremely common, and are identified in between 2% to 13% on abdominal imaging studies. Most pancreatic cysts are pseudocysts, serous cystic neoplasms, mucinous cystic neoplasms, or intraductal papillary mucinous neoplasms. The management of pancreatic cysts depends on whether a cyst is benign, has malignant potential, or harbors high-grade dysplasia or invasive carcinoma. The diagnosis of pancreatic cysts, and assessment of risk of malignant transformation, incorporates clinical history, computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasound, and fine-needle aspiration of cyst fluid. This article reviews the cyst fluid markers that are currently used, as well as promising markers under development.

Pancreatectomy for pancreatic incidentaloma: What are the risks?

BACKGROUND

Pancreatic incidentalomas (PI) are nowadays common but the benefit-risk balance of surgery remains difficult to determine.

METHODS

Monocentric retrospective study of 881 pancreatectomies comparing resected PI with symptomatic lesion. Univariate and multivariate (MV) analyses were done to identify risk factors of malignancy in PI undergoing surgery.

RESULTS

Overall, 32% of pancreatectomies were performed for PI. Median size of PI was 30 mm (vs 28 mm; p = 0.15) and 49% were cystic (vs 42%; p = 0.197). Resected PI were mostly located in distal pancreas (61% vs 34%; p < 0.001), less frequently malignant (49% vs 59%; p = 0.004). PNETs were more frequent in PI (50% vs 21%; p < 0.001). Distal pancreatectomy (36% vs 23%; p < 0.001) or parenchyma-sparing surgery (34% vs 13%; p < 0.001) were more frequently performed for PI. Overall mortality (1.1% vs 1.2%) and morbidity (70% vs 68%) were not significantly different between both groups. Severe morbidity was lower for PI (15% vs 22%; p = 0.007). In multivariate analysis, age>55 years (HR 6.14; p < 0.001), size >20 mm (HR:26.7; p < 0.001) and biliary dilatation (HR 29.9; p = 0.027) were independent risk factors of malignancy and, when associated, the likelihood of malignancy was above 90%.

CONCLUSIONS

PI represent about 30% of indications for pancreatectomy and when resected after careful selection are malignant in 50% of cases.

Experience-based surgical approach to pancreatic mucinous cystic neoplasms with ovarian-type stroma

The present study aimed to elucidate the clinicopathological characteristics of resected mucinous cystic neoplasm (MCN) with ovarian-type stroma and identify a surgical approach for MCN treatment, on the basis of Republic of Korean (Yonsei University College of Medicine, Seoul, South Korea) and Japanese (Nippon Medical School, Tokyo, Japan) bi-institutional collaboration. The present study retrospectively reviewed 55 MCNs with ovarian-type stroma using pathological re-examination. Clinicopathological features and preoperative clinical parameters were evaluated to predict malignant alterations in MCNs. The proportion of surgically treated MCNs has recently been increasing. All patients included in the present study were female, with a mean age of 47.9±13.3 years. Mural nodules were noted in 8 patients (14.5%) and the mean cyst size was 6.1±4.2 cm. A total of 9 patients (16.4%) were identified to exhibit non-invasive mucinous cystadenocarcinoma. The number of patients with small tumors (R²=-0.079, P=0.038) and asymptomatic pancreatic MCNs (P=0.022) was significantly increased (P<0.05), which resulted in the more frequent application of minimally invasive surgery (P<0.001). During the follow-up period (mean, 51.6 months; range, 1.1-242.8 months), no recurrence or tumor-associated mortality was identified. The presence of mural nodules (P=0.002) and a tumor size ≥4.5 cm (P=0.027) were identified as potential clinical parameters for predicting malignant transformation. The significance of mural nodules in predicting malignant transformation was increased in large MCNs (≥4.5 cm) of the pancreas compared with small MCNs (<4.5 cm) (P=0.002). Overall, non-invasive pancreatic MCNs are not aggressive, and minimally invasive pancreatectomy may be an effective approach for suitable patients.

Mucinous cystic neoplasms in male patients: two cases

Mucinous cystic neoplasms (MCNs) of the pancreas in male patients are very rare. Though few cases of MCNs in male patients have been reported, it is difficult to reveal them preoperatively. The first patient was a 50-year-old man and was incidentally found to have a cystic mass of 51 mm in the tail of the pancreas. We performed a distal pancreatectomy. The second patient was a 73-year-old man, incidentally found to have a cystic mass of 25 mm in diameter in the tail of the pancreas and a carcinoma of the bile duct. We performed a subtotal stomachpreserving pancreaticoduodenectomy and distal pancreatectomy. In both cases, the cystic lesion was diagnosed pathologically as MCNs. Since MCNs have the risk of malignancy, a resection is recommended. Cases of MCNs in male patients exhibit features that are similar to MCNs in women. We should recognize that MCNs of the pancreas in male patients exists.

[Cystic pancreatic tumors: diagnostics and new biomarkers]

Mortality due to pancreatic ductal adenocarcinoma (PDAC) will increase in the near future. The only curative treatment for PDAC is radical resection; however, even small carcinomas exhibit micrometastases leading to early relapse. Accordingly, detection of premalignant precursor lesions is important. In essence, PDAC develops from three precursor lesions: pancreatic intraepithelial lesions (PanIN), intraductal papillary-mucinous neoplasia (IPMN) and mucinous-cystic neoplasia (MCN). Together with serous cystic neoplasia (SCN) and solid pseudopapillary neoplasia (SPN), these cystic lesions constitute the most common cystic neoplasms in the pancreas. In the case of IPMN, main and branch duct IPMN have to be differentiated because of a markedly different malignancy potential. While main duct IPMN and MCN have a high malignancy transformation rate, branch duct IPMNs are more variable with respect to malignant transformation. This shows that differential diagnosis of cystic lesions is important; however, this is often very difficult to accomplish using conventional imaging. Novel biomarkers and diagnostic tools based on the molecular differences of cystic pancreatic lesions could be helpful to differentiate these lesions and facilitate early diagnosis. The aim is to distinguish the premalignant cysts from strictly benign cystic lesions and a timely detection of malignant transformation. This article provides an overview on the molecular characteristics of cystic pancreatic lesions as a basis for improved diagnostics and the development of new biomarkers.

Clinical Approach to Incidental Pancreatic Cystic Neoplasm in Outpatient Clinics

Cystic lesions of the pancreas are increasingly observed due to increased use of abdominal images. The malignant rate of pancreas cystic lesion varies widely between various types. Identification of malignant or high-risk lesions is important when determining the appropriate course of management. Using these image findings, including cyst size, presence of solid components, and pancreatic duct involvement, the 2012 International Association of Pancreatology (IAP) and the 2015 American Gastroenterological Association (AGA) guidelines provide a rationale in identifying higher risk patients requiring further workups using an endoscopic ultrasound (EUS). EUS with fine needle aspiration and cytology allows confirmation of the cyst type and determines the risk of malignancy. Small cysts with no suspicious features may undergo the regular imaging study for regular surveillance due to low risk for malignancy. In this review, the differences between the 2012 IAP and 2015 AGA guidelines are presented, In addition to possible recommendations for management and surveillance.

Nonmucinous Biliary Epithelium Is a Frequent Finding and Is Often the Predominant Epithelial Type in Mucinous Cystic Neoplasms of the Pancreas and Liver

Mucinous cystic neoplasms (MCNs) can occur in the pancreas and liver. Classically, these cystic lesions are lined by columnar mucinous epithelium with underlying ovarian-type stroma. It has been proposed that cysts with ovarian-type stroma and nonmucinous epithelium be considered separate entities in both the pancreas and liver. Using a series of 104 pancreatic and 32 hepatic cases, we aimed to further characterize the epithelium present in MCNs. Mucinous epithelium was defined as pancreatic intraepithelial neoplasia-like columnar cells with pale pink/clear apical mucin. Epithelial cells ranging from flat to cuboidal to short columnar without obvious mucin or goblet cells were classified as nonmucinous/biliary epithelium. A mixture (at least 5%) of mucinous and nonmucinous/biliary epithelium was noted in 81%. Almost half (47%) of the cases had abundant (>50%) nonmucinous/biliary epithelium. Of the 71 cases with ≤50% nonmucinous/biliary epithelium, 8 cases demonstrated high-grade dysplasia (7 pancreas, 1 liver) and 14 demonstrated invasive adenocarcinoma (11 pancreas, 3 liver). Conversely, of the 58 cases with >50% nonmucinous/biliary epithelium, not a single case of high-grade dysplasia (P=0.007) or invasive carcinoma (P<0.001) was identified. In summary, nonmucinous/biliary epithelium frequently occurs in MCNs of the pancreas and liver. As mucinous and nonmucinous/biliary epithelia often occur together, there does not appear to be enough evidence to regard cases with predominantly nonmucinous/biliary epithelium as separate entities. Our findings suggest that mucinous change is a "progression" phenomenon in MCNs of the pancreas and liver, and only when abundant mucinous epithelium is present is there a risk of progression to malignancy.

Surgical Management of Pancreatic Cysts: A Shifting Paradigm Toward Selective Resection

Due to the widespread use of high-quality cross-sectional imaging, pancreatic cystic neoplasms are being diagnosed with increasing frequency. Clinicians are therefore asked to counsel a growing number of patients with pancreatic cysts diagnosed incidentally at an early, asymptomatic stage. Over the last two decades, accumulating knowledge on the biologic behavior of these neoplasms along with improved diagnostics through imaging and endoscopic cyst fluid analysis have allowed for a selective therapeutic approach toward these neoplasms. On one end of the management spectrum, observation is recommended for typically benign lesions (serous cystadenoma), and on the other end, upfront resection is recommended for likely malignant lesions (main duct IPMN, mucinous cystadenoma, solid pseudopapillary tumor, and cystic pancreatic neuroendocrine tumors). In between, management of premalignant lesions (branch duct IPMN) is dictated by the presence of high-risk features. In general, resection should be considered whenever the risk of malignancy is higher than the risk of the operation. This review aims to describe the evolution and current status of evidence guiding the selection of patients with pancreatic cystic neoplasms for surgical resection, along with a specific discussion on the type of resection required and expected outcomes.

Anaplastic Pancreatic Carcinoma Arising Within a Mucinous Cystic Neoplasm of the Pancreas: A Case Report and a Brief Review of the Literature

Background: Anaplastic pancreatic carcinomas (APCs) are among the least frequently encountered pancreatic malignancies, ranging from 0.5% to 7% of all nonendocrine pancreatic malignancies. Furthermore, few cases of APCs have been described arising within a pancreatic mucinous cystic neoplasm (MCN). Case Presentation: A 36-year-old female presented with left upper quadrant pain and a 10 × 8 cm complex cystic mass in the pancreatic tail. Fine needle aspiration of the cyst showed papillary clusters of cells with mild cytological atypia, cyst fluid carcinoembryonic antigen >4000 ng/mL, and amylase of 25 U/L. After an open distal pancreatectomy and splenectomy, the specimen revealed an MCN with multifocal microscopic foci of invasive well-differentiated adenocarcinoma. After additional sampling, foci of undifferentiated malignancy-morphologically resembling sarcomas but with immunohistochemical staining consistent with anaplastic carcinoma-were identified. The patient had an uneventful recovery and is currently undergoing a regimen of gemcitabine-based adjuvant chemotherapy; she remains disease-free at 5 months after initial diagnosis. Conclusions: In this study, we describe a rare case of APC originating from a large pancreatic MCN lesion. This case underlines the importance of scrupulous pathological evaluation of the entire MCN epithelium and adds to the limited world literature of APC originating from pancreatic MCN lesions.

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.

Natural History of Pancreatic Cysts

Pancreatic cystic neoplasms are discovered with increasing frequency. Accurate knowledge of the natural history of cystic neoplasms is crucial to develop useful and cost-effective strategies for surveillance and surgical resection. To date, the natural history of cystic neoplasms is still incomplete due to lack of adequate diagnostic accuracy in the absence of surgical pathology. Nevertheless, current evidence points to risk factors for malignant transformation to help clinical management. New biomarkers that accurately distinguish cyst neoplasms and those most likely to progress to cancer would help clarify the natural history of cystic neoplasms.

Association of Preoperative Risk Factors With Malignancy in Pancreatic Mucinous Cystic Neoplasms: A Multicenter Study

Importance

Pancreatic mucinous cystic neoplasms (MCNs) harbor malignant potential, and current guidelines recommend resection. However, data are limited on preoperative risk factors for malignancy (adenocarcinoma or high-grade dysplasia) occurring in the setting of an MCN.

Objectives

To examine the preoperative risk factors for malignancy in resected MCNs and to assess outcomes of MCN-associated adenocarcinoma.

Design, Setting, and Participants

Patients who underwent pancreatic resection of MCNs at the 8 academic centers of the Central Pancreas Consortium from January 1, 2000, through December 31, 2014, were retrospectively identified. Preoperative factors of patients with and without malignant tumors were compared. Survival analyses were conducted for patients with adenocarcinoma.

Main Outcomes and Measures

Binary logistic regression models were used to determine the association of preoperative factors with the presence of MCN-associated malignancy.

Results

A total of 1667 patients underwent resection of pancreatic cystic lesions, and 349 (20.9%) had an MCN (310 women [88.8%]; mean (SD) age, 53.3 [14.7] years). Male sex (odds ratio [OR], 3.72; 95% CI, 1.21-11.44; P = .02), pancreatic head and neck location (OR, 3.93; 95% CI, 1.43-10.81; P = .01), increased radiographic size of the MCN (OR, 1.17; 95% CI, 1.08-1.27; P < .001), presence of a solid component or mural nodule (OR, 4.54; 95% CI, 1.95-10.57; P < .001), and duct dilation (OR, 4.17; 95% CI, 1.63-10.64; P = .003) were independently associated with malignancy. Malignancy was not associated with presence of radiographic septations or preoperative cyst fluid analysis (carcinoembryonic antigen, amylase, or mucin presence). The median serum CA19-9 level for patients with malignant neoplasms was 210 vs 15 U/mL for those without (P = .001). In the 44 patients with adenocarcinoma, 41 (93.2%) had lymph nodes harvested, with nodal metastases in only 14 (34.1%). Median follow-up for patients with adenocarcinoma was 27 months. Adenocarcinoma recurred in 11 patients (25%), with a 64% recurrence-free survival and 59% overall survival at 3 years.

Conclusions and Relevance

Adenocarcinoma or high-grade dysplasia is present in 14.9% of resected pancreatic MCNs for which risks include male sex, pancreatic head and neck location, larger MCN, solid component or mural nodule, and duct dilation. Mucinous cystic neoplasm-associated adenocarcinoma appears to have decreased nodal involvement at the time of resection and increased survival compared with typical pancreatic ductal adenocarcinoma. Indications for resection of MCNs should be revisited.

Management of Incidental Pancreatic Cysts: A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee (IFC) presents recommendations for managing pancreatic cysts that are incidentally detected on CT or MRI. These recommendations represent an update from the pancreatic component of the JACR 2010 white paper on managing incidental findings in the adrenal glands, kidneys, liver, and pancreas. The Pancreas Subcommittee-which included abdominal radiologists, a gastroenterologist, and a pancreatic surgeon-developed this algorithm. The recommendations draw from published evidence and expert opinion, and were finalized by informal iterative consensus. Algorithm branches successively categorize pancreatic cysts based on patient characteristics and imaging features. They terminate with an ascertainment of benignity and/or indolence (sufficient to discontinue follow-up), or a management recommendation. The algorithm addresses most, but not all, pathologies and clinical scenarios. Our goal is to improve quality of care by providing guidance on how to manage incidentally detected pancreatic cysts.

Diversity of Precursor Lesions For Pancreatic Cancer: The Genetics and Biology of Intraductal Papillary Mucinous Neoplasm

Pancreatic ductal adenocarcinoma (PDA), one of the most lethal cancers worldwide, is associated with two main types of morphologically distinct precursors—pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN). Although the progression of PanIN into invasive cancer has been well characterized, there remains an urgent need to understand the biology of IPMNs, which are larger radiographically detectable cystic tumors. IPMNs comprise a number of subtypes with heterogeneous histopathologic and clinical features. Although frequently remaining benign, a significant proportion exhibits malignant progression. Unfortunately, there are presently no accurate prognosticators for assessing cancer risk in individuals with IPMN. Moreover, the fundamental mechanisms differentiating PanIN and IPMN remain largely obscure, as do those that distinguish IPMN subtypes. Recent studies, however, have identified distinct genetic profiles between PanIN and IPMN, providing a framework to better understand the diversity of the precursors for PDA. Here, we review the clinical, biological, and genetic properties of IPMN and discuss various models for progression of these tumors to invasive PDA.

Intraductal papillary mucinous neoplasms and mucinous cystadenomas: current status and recommendations

The real prevalence of pancreatic cystic lesions remains unknown. The malignant potential of some of these lesions remains a cause for significant concern. Thus, it is mandatory to develop a strategy to clearly discriminate those cysts with a potential for malignant transformation from those that do not carry any significant risk. Intraductal papillary mucinous neoplasms and mucinous cystadenomas are mucinous cystic neoplasms with a known malignant potential that have gained greater recognition in recent years. However, despite the numerous studies that have been carried out, their differential diagnosis among other cysts subtypes and their therapeutic approach continue to be a challenge for clinicians. This review contains a critical approach of the current recommendations and management strategies regarding intraductal papillary mucinous neoplasms and mucinous cystadenomas, as well as highlighting the limitations exposed in current guidelines.

Therapeutic Approach to Cystic Neoplasms of the Pancreas

Management of cystic neoplasms of the pancreas is challenging as it relies on radiologic and cyst fluid markers to discriminate between benign and pre-cancerous lesions, however their ability to predict malignancy is limited. While asymptomatic serous cystadenomas can be managed conservatively, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms are more difficult to manage. A selective approach, based on the preoperative likelihood of high-grade dysplasia or invasive disease, is the standard of care. Research is focusing on the development of pre-operative markers for identifying high risk lesions, which will spare patients with low-risk or benign lesions the risks of pancreatectomy.

Spectrum and Classification of Cystic Neoplasms of the Pancreas

As patients are living longer and axial imaging is more widespread, increasing numbers of cystic neoplasms of the pancreas are found. Intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are the most common. The revised Sendai guidelines provide a safe algorithm for expectant management of certain cystic neoplasms; however, studies are ongoing to identify further subgroups that can be treated nonoperatively. For those patients with high-risk clinical features or symptoms, surgical resection can be performed safely at high-volume pancreatic centers. Accurate diagnosis is critical for accurate decision making.

Preoperative characteristics and cytological features of 136 histologically confirmed pancreatic mucinous cystic neoplasms

BACKGROUND

Mucinous cystic neoplasms (MCNs) of the pancreas present a management conundrum. The majority are benign but all are resected due to their malignant potential. Recent studies have recommended nonsurgical management. In the current study, the authors analyzed the preoperative imaging, cytology, and cyst fluid characteristics of 136 histologically confirmed MCNs to assess predictors of a high-risk (HR) cyst for surgical triage.

METHODS

MCNs resected at the Massachusetts General Hospital between 1990 and 2014 formed the study cohort. Patient demographics, cyst size, and mural nodules (MNs) by endoscopic ultrasound, cytology, and cyst fluid carcinoembryonic antigen and amylase levels were correlated with histological grade. A HR cyst was defined as high-grade dysplasia or invasive carcinoma on histology. Performance characteristics were assessed for each parameter, with a cyst size ≥3 cm or a MN on imaging and malignant cytology considered to be "true-positive" results for predicting malignancy.

RESULTS

Only 15 of the 136 cysts had HR histology (11%). On average, patients with HR cysts were older than those with low-risk cysts (55 years vs 49 years, respectively). High-grade cytology was the most accurate predictor of malignancy (95%) followed by MN and cyst size together (88%) and MN alone (83%). The average carcinoembryonic antigen level (in ng/mL) increased with the grade of dysplasia but the ranges overlapped between low risk and HR cysts.

CONCLUSIONS

To the authors' knowledge, the current study is the largest series to date analyzing the cytological features of histologically confirmed MCN. Cytology is insensitive but very specific for detecting a HR MCN and outperformed imaging for the detection of HR MCN. Endoscopic ultrasound-guided fine-needle aspiration and cytology should be performed on any clinically suspected MCN that is being considered for conservative management. Cancer Cytopathol 2017;125:169-177. © 2016 American Cancer Society.

Surveillance for neoplasia in the pancreas

Despite its low incidence in the general population, pancreatic cancer is one of the leading causes of cancer-related mortality. Survival greatly depends on operability, but most patients present with unresectable disease. Therefore, there is great interest in the early detection of pancreatic cancer and its precursor lesions by surveillance. Worldwide, several programs have been initiated for individuals at high risk for pancreatic cancer. Their first results suggest that surveillance in high-risk individuals is feasible, but their effectiveness in decreasing mortality remains to be proven. This review will discuss which individuals are eligible for surveillance, which lesions are aimed to be detected, and which surveillance modalities are being used in current clinical practice. Furthermore, it addresses the management of abnormalities found during surveillance and topics for future research.