Pathologic examination accurately predicts prognosis in mucinous cystic neoplasms of the pancreas

Incidental Mucinous Neoplasms of the Pancreas: Performance of the AGA, European, and IAP Guidelines in Advising Further Management After Endoscopic Ultrasound-guided Fine Needle Aspiration

OBJECTIVES

We compared the performance of AGA-2015, ESG-2018, and IAP-2024 guidelines in referring patients for surgery versus surveillance when applied to incidental after diagnosis by EUS-FNA.

METHODS

This is a single-center, retrospective study with prospective data collection. PLs identified incidentally on CT or MRI/MRCP performed for other diseases with inconclusive imaging results were eligible for analysis. After EUS-FNA and microhistologic diagnosis, each of the guidelines was applied; sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were compared.

RESULTS

One hundred and forty asymptomatic patients (mean age 64.7 y, 61% females) had a confirmed diagnosis of MN. Of these, 42 (30%) had "high-risk stigmata," and 16 (11.4%) were malignant. AGA-2015, ESG-2018, and IAP-2024 criteria would have advised surgery unnecessarily in 66%, 15%, and 46%, respectively ( P <0.001). AGA-2015, ESG-2018, and IAP-2024 criteria failed to identify 59%, 46.1%, and 33.3% of HGD/IC, respectively ( P =1.00).

CONCLUSIONS

The AGA-2015 criteria were highly specific, while IAP-2024 had superior sensitivity. All had moderate sensitivity to indicate surgery, and all missed similar numbers of malignant lesions. Performing EUS-FNA before the application of guidelines seems appropriate to guide further management of asymptomatic PLs, preventing unnecessary surgery and referring patients appropriately for surveillance. The ESG-2018 guideline proved the most accurate for this purpose.

Reducing the burden of pancreatic cancer by surveilling mucinous cystic neoplasms: are we there yet?

Pancreatic cystic neoplasms are a common condition, with intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) being of particular concern due to their potential for malignant transformation. Resection of these lesions before progression to invasive cancer represents a crucial opportunity to reduce the burden of pancreatic cancer. However, the benefit of early-resection must be weighed against the risk of overtreatment. Applying current guidelines, nearly half of the patients who undergo resection for IPMN might not have required surgery, while malignancy is detected in only 16 % of resected MCNs. This raises concerns, particularly given the increasing detection of small cysts with the widespread use of radiological imaging and the significant postoperative risks, including exocrine and endocrine insufficiency. Emerging evidence suggests that surveillance strategies could be more broadly applied, reducing unnecessary surgeries. This review aims to reassess the current evidence regarding both surgical resection and surveillance of IPMNs and MCNs.

Precursor lesions in familial and hereditary pancreatic cancer

Infiltrating ductal adenocarcinoma of the pancreas, referred to here as "pancreatic cancer," is one of the deadliest of all of the solid malignancies. The five-year survival rate in the United States for individuals diagnosed today with pancreatic cancer is a dismal 12%. Many invasive cancers, including pancreatic cancer, however, arise from histologically and genetically well-characterized precursor lesions, and these precancers are curable. Precursor lesions therefore are an attractive target for early detection and treatment. This is particularly true for individuals with an increased risk of developing invasive cancer, such as individuals with a strong family history of pancreatic cancer, and individuals with a germline variant known to increase the risk of developing pancreatic cancer. There is therefore a need to understand the precursor lesions that can give rise to invasive pancreatic cancer in these individuals.

Multiparameter Analysis Using 18F-FDG PET/CT in the Differential Diagnosis of Pancreatic Cystic Neoplasms

Purpose

To evaluate multiparametric analysis in differential diagnosis between pancreatic serous cystic neoplasms (SCNs) and mucinous cystic neoplasms (MCNs) as well as the differentiation of the benign and malignant MCNs with ¹⁸F-FDG (18-fluorodeoxyglucose) PET/CT (positron emission tomography).

Methods

Forty patients with total of 41 lesions (SCNs: 27/41; MCNs: 14/41), who were preoperatively examined with ¹⁸F-FDG PET/CT, were retrospectively analyzed. Multiple quantitative parameters using conventional and texture features were included. The combined model was established with complementary PET/MR parameters. The differential diagnostic efficacy of each independent parameter and the combined model were evaluated with receiver operating characteristic (ROC) analysis. Integrated discriminatory improvement (IDI) and net reclassification improvement (NRI) were used to evaluate improvement of diagnostic efficacy by using combination of multiple parameters.

Results

Among all independent parameters, the percentile 5th (0.88 ± 0.38 vs 0.47 ± 0.23, P < 0.001) showed the highest discriminative diagnostic value. The combination of multiple parameters can improve the differential diagnostic efficacy of SCNs and MCNs (sensitivity = 71.4%, specificity = 77.8%, and AUC = 0.788), and the addition of texture parameters to the conventional parameters allowed a significant reclassification with IDI = 0.236 (95% CI: 0.095-0.377) and categorical NRI = 0.434 (95% CI: 0.030-0.838). SURmax (tumor to normal pancreas ratio, T/P) and SURmax (tumor to aorta ratio, T/A) both showed the highest discriminative diagnostic value (sensitivity = 100.0%, specificity = 70.0%, AUC = 0.900, and Youden index = 0.700) in the differential diagnosis of benign and malignant MCNs, with the cutoff values of 0.84 and 0.90, respectively.

Conclusion

Combination of multiple parameters using ¹⁸F-FDG PET/CT could further improve differentiation between pancreatic SCNs and MCNs. SURmax (T/P) and SURmax (T/A) could improve differential diagnosis of benign and malignant MCNs.

Pancreatic mucinous cystic neoplasms: a clinicopathological study of 11 cases and detailed review of literature

Background

Mucinous cystic neoplasms (MCNs) of pancreas are relatively rare, occur almost exclusively in middle-aged females, and are overwhelmingly located in the body and tail of the pancreas, histologically show an ovarian type stroma. MCNs are premalignant, low aggressive tumors. Here we describe the clinicopathologic and radiologic features and follow up of cases diagnosed in our practice. We also present a detailed review of recent literature.

Materials and methods

Based on strict criteria, 11 cases diagnosed between 2002 and 2016 were included in the study.

Results

All cases were reviewed histologically. Mean and median age was 46.7 and 46 years respectively. All patients were females and 9 out of 11 cases were located in the body and/or tail of the pancreas. Mean tumor size was 8 cm. Grossly, cysts were uni or multilocular and ranged from a few millimeters to several centimeters in diameter. Microscopically, all cases showed characteristic tall columnar, mucin producing epithelium and ovarian type stroma. Atypia was mild in 8 cases and severe in 3 cases. The latter 3 cases were classified as non-invasive MCNs with high grade dysplasia (2 cases) and MCN with an associated invasive carcinoma (1 case). On immunohistochemistry, all cases showed epithelial positivity for cytokeratin AE1/AE3 and stromal positivity for vimentin and smooth muscle actin. Follow up was available in 7 cases. All patients were alive and well with no recurrence.

Conclusions

Our cases show features similar to those described in other published studies although cases in our series tended to be larger in number. Since these tumors are relatively rare, premalignant and have strict diagnostic criteria, they must always be considered in the differential diagnosis of pancreatic mucinous cystic lesions. Larger studies incorporating greater number of patients and more detailed follow up will help in increasing our understanding of MCNs.

A semicentennial of pancreatic pathology: the genetic revolution is here, but don't throw the baby out with the bath water!

The last 50 years have witnessed an explosion in our understanding of the pathology of pancreatic diseases. Entities known to exist 50 years ago have been defined more precisely and are now better classified. New entities, previously not recognized, have been discovered and can now be treated. Importantly, new tools have been developed that have unraveled the fundamental biological drivers of a number of pancreatic diseases. Many of these same tools have also been applied clinically, supplementing the tried and true hematoxylin and eosin stained slide with a plethora of new, highly sensitive and specific tests that improve diagnostic accuracy and delineate best treatments. As exciting as these many advances are, our knowledge of pancreatic pathology remains incomplete, and there is much to be learned.

Cancer overdiagnosis: a biological challenge and clinical dilemma

For cancer screening to be successful, it should primarily detect cancers with lethal potential or their precursors early, leading to therapy that reduces mortality and morbidity. Screening programmes have been successful for colon and cervical cancers, where subsequent surgical removal of precursor lesions has resulted in a reduction in cancer incidence and mortality. However, many types of cancer exhibit a range of heterogeneous behaviours and variable likelihoods of progression and death. Consequently, screening for some cancers may have minimal impact on mortality and may do more harm than good. Since the implementation of screening tests for certain cancers (for example, breast and prostate cancers), a spike in incidence of in situ and early-stage cancers has been observed, but a link to reduction in cancer-specific mortality has not been as clear. It is difficult to determine how many of these mortality reductions are due to screening and how many are due to improved treatments of tumours. In cancers with lower incidence but high mortality (for example, pancreatic cancer), screening has focused on high-risk populations, but challenges similar to those for general population screening remain, particularly with regard to finding lesions with difficult-to-characterize malignant potential (for example, intraductal papillary mucinous neoplasms). More sensitive screening methods are detecting smaller and smaller lesions, but this has not been accompanied by a comparable reduction in the incidence of invasive cancers. In this Opinion article, we focus on the contribution of screening in general and high-risk populations to overdiagnosis, the effects of overdiagnosis on patients and emerging strategies to reduce overdiagnosis of indolent cancers through an understanding of tumour heterogeneity, the biology of how cancers evolve and progress, the molecular and cellular features of early neoplasia and the dynamics of the interactions of early lesions with their surrounding tissue microenvironment.

Mucinous cystadenoma of the pancreas associated with pregnancy. Case report and review of the literature

Objective. We present a rare pathology with uncommon onset. Background. Mucinous cystic pancreatic neoplasms (MCNs) are rare tumors, which generally occur in the fifth and sixth decades of women. Although some tumours are frankly malignant, all are in fact considered to be potentially malignant. Case report. We present the case of a 30-year-old patient, with a 16/11 cm tumor located in the pancreas body, which was diagnosed 8 months after birth. The preoperative assessment of the pancreatic lesion suggested the diagnosis of mucosal cyst neoplasm, without being able to determine its benign or malignant nature. Central pancreatectomy was performed with a good postoperative evolution. Histopathologic result was represented by mucinous pancreatic chistadenoma. Two years after surgical intervention, the patient presented no signs of recurrence or pancreatic (exocrine or endocrine) secretion deficiency. Conclusions. Preoperative imaging evaluation could be suggestive for mucinous cystic tumour, but this cannot specify however the nature of the tumor. The postpartum occurrence could establish a possible relationship between hormonal levels encountered during pregnancy and the development of this tumor, taking into considerations the ovarian-type stroma and the presence of hormone (estrogen and progesterone) receptors in this neoplasm. Central pancreatectomy without anastomosis preserves the functions of pancreas, and also decreases morbidity.

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.

Quantitative imaging to evaluate malignant potential of IPMNs

Objective

To investigate using quantitative imaging to assess the malignant potential of intraductal papillary mucinous neoplasms (IPMNs) in the pancreas.

Background

Pancreatic cysts are identified in over 2% of the population and a subset of these, including intraductal papillary mucinous neoplasms (IPMNs), represent pre-malignant lesions. Unfortunately, clinicians cannot accurately predict which of these lesions are likely to progress to pancreatic ductal adenocarcinoma (PDAC).

Methods

We investigated 360 imaging features within the domains of intensity, texture and shape using pancreatic protocol CT images in 53 patients diagnosed with IPMN (34 “high-grade” [HG] and 19 “low-grade” [LG]) who subsequently underwent surgical resection. We evaluated the performance of these features as well as the Fukuoka criteria for pancreatic cyst resection.

Results

In our cohort, the Fukuoka criteria had a false positive rate of 36%. We identified 14 imaging biomarkers within Gray-Level Co-Occurrence Matrix (GLCM) that predicted histopathological grade within cyst contours. The most predictive marker differentiated LG and HG lesions with an area under the curve (AUC) of .82 at a sensitivity of 85% and specificity of 68%. Using a cross-validated design, the best logistic regression yielded an AUC of 0.96 (σ = .05) at a sensitivity of 97% and specificity of 88%. Based on the principal component analysis, HG IPMNs demonstrated a pattern of separation from LG IPMNs.

Conclusions

HG IPMNs appear to have distinct imaging properties. Further validation of these findings may address a major clinical need in this population by identifying those most likely to benefit from surgical resection.

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.

Granulocyte-colony stimulating factor producing mucinous cystic neoplasm with an associated invasive carcinoma of the pancreas

The present case study documents an autopsy case of granulocyte-colony stimulating factor (G-CSF)-producing mucinous cystic neoplasm (MCN), with an associated invasive carcinoma of the pancreas. A 65-year-old woman presented to Omuta City Hospital (Omuta Japan) with a primary complaint of abdominal pain. Multiple liver nodules and a pancreatic cyst were detected upon abdominal computed tomography. Initially, liver abscess was suspected as the patient exhibited leukocytosis and elevated C-reactive protein level. However, the serum concentration of G-CSF was 98.8 pg/ml (normal, <39.0 pg/ml). At 6 weeks after admission, the patient succumbed to liver failure. At autopsy, a cystic lesion was identified in the pancreatic tail that contained bloody necrotic fluid. Microscopically, the cystic lesion was composed of columnar and mucin-producing epithelium associated with ovarian-type subepithelial stroma. The stroma exhibited positive immunostaining for vimentin, estrogen receptor and progesterone receptor. Calcification on the cystic wall was observed. The tumor invaded the pancreatic parenchyma and metastasized to the liver and lungs. The lesion was diagnosed as invasive adenocarcinoma arising in MCN. By contrast, liver nodules predominantly consisted of pleomorphic cancer cells with small foci of adenocarcinoma. Pancreatic and hepatic cancer cells were confirmed to be positive for G-CSF staining. The present case report indicates that G-CSF-producing MCNs may be associated with an aggressive clinical course, particularly when anaplastic changes are observed.

Comparison of the diagnostic accuracy of three current guidelines for the evaluation of asymptomatic pancreatic cystic neoplasms

Asymptomatic pancreatic cysts are a common clinical problem but only a minority of these cases progress to cancer. Our aim was to compare the accuracy to detect malignancy of the 2015 American Gastroenterological Association (AGA), the 2012 International Consensus/Fukuoka (Fukuoka guidelines [FG]), and the 2010 American College of Radiology (ACR) guidelines.We conducted a retrospective study at 3 referral centers for all patients who underwent resection for an asymptomatic pancreatic cyst between January 2008 and December 2013. We compared the accuracy of 3 guidelines in predicting high-grade dysplasia (HGD) or cancer in resected cysts. We performed logistic regression analyses to examine the association between cyst features and risk of HGD or cancer.A total of 269 patients met inclusion criteria. A total of 228 (84.8%) had a benign diagnosis or low-grade dysplasia on surgical pathology, and 41 patients (15.2%) had either HGD (n = 14) or invasive cancer (n = 27). Of the 41 patients with HGD or cancer on resection, only 3 patients would have met the AGA guideline's indications for resection based on the preoperative cyst characteristics, whereas 30/41 patients would have met the FG criteria for resection and 22/41 patients met the ACR criteria. The sensitivity, specificity, positive predictive value, negative predictive value of HGD, and/or cancer of the AGA guidelines were 7.3%, 88.2%, 10%, and 84.1%, compared to 73.2%, 45.6%, 19.5%, and 90.4% for the FG and 53.7%, 61%, 19.8%, and 88% for the ACR guidelines. In multivariable analysis, cyst size >3 cm, compared to ≤3 cm, (odds ratio [OR] = 2.08, 95% confidence interval [CI] = 1.11, 4.2) and each year increase in age (OR = 1.07, 95% CI = 1.03, 1.11) were positively associated with risk of HGD or cancer on resection.In patients with asymptomatic branch duct-intraductal papillary mucinous neoplasms or mucinous cystic neoplasms who underwent resection, the prevalence rate of HGD or cancer was 15.2%. Using the 2015 AGA criteria for resection would have missed 92.6% of patients with HGD or cancer. The more "inclusive" FG and ACR had a higher sensitivity for HGD or cancer but lower specificity. Given the current deficiencies of these guidelines, it will be important to determine the acceptable rate of false-positives in order to prevent a single true-positive.

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 Undifferentiated Solitary Mucinous Cystic Lesion of the Pancreas: A Clinical Dilemma

BACKGROUND

Management of solitary mucinous cystic lesions of the pancreas (MCLs) relies on correct differentiation between branch duct intraductal papillary mucinous neoplasm (BD-IPMN) and mucinous cystic neoplasm (MCN). Current international consensus guidelines recommend resection for MCN, and unifocal BD-IPMN can be followed in the absence of worrisome features/high-risk stigmata. We hypothesized that preoperative differentiation of solitary MCLs is suboptimal, and that all solitary MCLs should be treated similarly.

STUDY DESIGN

A retrospective review of an institutional database (2003 to 2016) identified 711 patients who underwent resection for pancreatic cyst. Only lesions that met cytologic or biochemical criteria for diagnosis of MCLs were included. Mucinous cystic neoplasms were defined by presence of ovarian stroma on pathology. Patients with formal preoperative diagnosis of BD-IPMN (multifocality, GNAS mutation) were excluded.

RESULTS

One hundred and eighty solitary MCLs were identified on preoperative imaging (mean age 54 years, 24% men). On surgical pathology, 108 were MCNs and 72 BD-IPMNs. There was no difference in invasive rate (7 of 108 [6.5%] MCNs vs 4 of 72 [5.6%] BD-IPMN; p ≈ 1). Pancreatic ductal connectivity was reported on imaging/endoscopy in 10 of 108 (9%) MCNs and 22 of 72 (31%) BD-IPMNs, representing 67% accuracy in differentiating MCNs from BD-IPMNs. On multivariate analysis, typical risk factors failed to predict invasiveness in either MCNs or BD-IPMNs. When all undifferentiated solitary MCLs were analyzed together, older age (p = 0.03) and cyst size (p = 0.04) were associated with increased invasive rate in multivariate analysis.

CONCLUSIONS

Unreliable differentiation and limited ability to predict invasiveness make solitary MCLs clinically challenging. With similar invasive rates, MCN and unifocal BD-IPMNs should be merged into one new entity for management, the undifferentiated solitary MCL.

Nature and management of pancreatic mucinous cystic neoplasm (MCN): A systematic review of the literature

BACKGROUND

The current management of pancreatic mucinous cystic neoplasms (MCN) is defined by the consensus European, International Association of Pancreatology and American College of Gastroenterology guidelines. However, the criterion for surgical resection remains uncertain and differs between these guidelines. Therefore through this systematic review of the existing literature we aimed to better define the natural history and prognosis of these lesions, in order to clarify recommendations for future management.

METHODS

A systematic literature search was performed (PubMed, EMBASE, Cochrane Library) for studies published in the English language between 1970 and 2015.

RESULTS

MCNs occur almost exclusively in women (female:male 20:1) and are mainly located in the pancreatic body or tail (93-95%). They are usually found incidentally at the age of 40-60 years. Cross-sectional imaging and endoscopic ultrasound are the most frequently used diagnostic tools, but often it is impossible to differentiate MCNs from branch duct intraductal papillary mucinous neoplasms (BD-IPMN) or oligocystic serous adenomas pre-operatively. In resected MCNs, 0-34% are malignant, but in those less than 4 cm only 0.03% were associated with invasive adenocarcinoma. No surgically resected benign MCNs were associated with a synchronous lesion or recurrence; therefore further follow-up is not required after resection. Five-year survival after surgical resection of a malignant MCN is approximately 60%.

CONCLUSIONS

Compared to other pancreatic tumors, MCNs have a low aggressive behavior, with exceptionally low rates of malignant transformation when less than 4 cm in size, are asymptomatic and lack worrisome features on pre-operative imaging. This differs significantly from the natural history of small BD-IPMNs, supporting the need to differentiate mucinous cyst subtypes pre-operatively, where possible. The findings support the recommendations from the recent European Consensus Guidelines, for the more conservative management of MCNs.

Pancreatic mucinous cystadenocarcinoma: Epidemiology and outcomes

BACKGROUND

Pancreatic mucinous cystadenocarcinoma is a rare malignancy. Our aim was to investigate the demographic, pathological characteristics, treatment modalities and survival of patients with mucinous cystadenocarcinoma via the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) database analysis.

MATERIALS AND METHODS

This was a retrospective study of SEER database's records on patients with mucinous cystadenocarcinoma diagnosed from 1988 to 2012. Primary outcome measures were clinico-pathological characteristics, observed and disease-specific survival.

RESULTS

A total of 507 patients were identified. Median age at diagnosis was 67 years and most patients were female (68.4%). The tumors were mainly low grade (82.9%, grade I-II) and frequently localized (42.8%) in the body/tail of the pancreas (45.6%). According to Kaplan-Meier curves observed survival was 111 months (95%CI: 82.5, 139.5) vs 14 months (95% CI: 10.9, 17.1) vs 4 months (95%CI: 2.9, 5.1) for patients with localized, regional and distant disease, respectively. One-year disease-specific survival for patients with localized disease was 90.1%, vs. 56.7% for those with regional and 18.7% with distant tumor spread.

CONCLUSIONS

Mucinous cystadenocarcinomas tend to be low grade tumors, localized to the pancreatic body/tail. Surgery as the primary therapeutic intervention and tumor stage are independent predictors of disease-specific survival.

Advanced endoscopic ultrasound management techniques for preneoplastic pancreatic cystic lesions

Pancreatic cystic lesions can be benign, premalignant or malignant. The recent increase in detection and tremendous clinical variability of pancreatic cysts has presented a significant therapeutic challenge to physicians. Mucinous cystic neoplasms are of particular interest given their known malignant potential. This review article provides a brief but comprehensive review of premalignant pancreatic cystic lesions with advanced endoscopic ultrasound (EUS) management approaches. A comprehensive literature search was performed using PubMed, Cochrane, OVID and EMBASE databases. Preneoplastic pancreatic cystic lesions include mucinous cystadenoma and intraductal papillary mucinous neoplasm. The 2012 International Sendai Guidelines guide physicians in their management of pancreatic cystic lesions. Some of the advanced EUS management techniques include ethanol ablation, chemotherapeutic (paclitaxel) ablation, radiofrequency ablation and cryotherapy. In future, EUS-guided injections of drug-eluting beads and neodymium:yttrium aluminum agent laser ablation is predicted to be an integral part of EUS-guided management techniques. In summary, International Sendai Consensus Guidelines should be used to make a decision regarding management of pancreatic cystic lesions. Advanced EUS techniques are proving extremely beneficial in management, especially in those patients who are at high surgical risk.

Uncommon presentations of common pancreatic neoplasms: a pictorial essay

Pancreatic neoplasms are a wide group of solid and cystic lesions with different and often characteristic imaging features, clinical presentations, and management. Among solid tumors, ductal adenocarcinoma is the most common: it arises from exocrine pancreas, comprises about 90% of all pancreatic neoplasms, and generally has a bad prognosis; its therapeutic management must be multidisciplinary, involving surgeons, oncologists, gastroenterologists, radiologists, and radiotherapists. The second most common solid pancreatic neoplasms are neuroendocrine tumors: they can be divided into functioning or non-functioning and present different degrees of malignancy. Cystic pancreatic neoplasms comprise serous neoplasms, which are almost always benign, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms, which can vary from benign to frankly malignant lesions, and solid pseudopapillary tumors. Other pancreatic neoplasms, such as lymphoma, metastases, or pancreatoblastoma, are rarely seen in clinical practice and have different and sometimes controversial managements. Rare clinical presentations and imaging appearance of the most common pancreatic neoplasms, both solid and cystic, are more frequently seen and clinically relevant than rare pancreatic tumors; their pathologic and radiologic appearances must be known to improve their management. The purpose of this paper is to present some rare or uncommon clinical and radiological presentations of common pancreatic neoplasms providing examples of multi-modality imaging approach with pathologic correlations, thus describing the histopathological bases that can explain the peculiar imaging features, in order to avoid relevant misdiagnosis and to improve lesion management.

Genetic Diversity of Pancreatic Ductal Adenocarcinoma and Opportunities for Precision Medicine

Patients with pancreatic ductal adenocarcinoma (PDA) have a poor prognosis despite new treatments; approximately 7% survive for 5 years. Although there have been advances in systemic, primarily cytotoxic, therapies, it has been a challenge to treat patients with PDA using targeted therapies. Sequence analyses have provided a wealth of information about the genetic features of PDA and have identified potential therapeutic targets. Preclinical and early-phase clinical studies have found specific pathways could be rationally targeted; it might also be possible to take advantage of the genetic diversity of PDAs to develop therapeutic agents. The genetic diversity and instability of PDA cells have long been thought of as obstacles to treatment, but are now considered exploitable features. We review the latest findings in pancreatic cancer genetics and the promise of targeted approaches in PDA therapy.

It's a SMAD/SMAD World

DPC4/SMAD4 mutations are associated with aggressive pancreatic cancer. In this issue of Cell, Whittle et al. demonstrate that Runx3 expression combined with Dpc4/Smad4 status can predict the metastatic propensity of pancreatic tumors, providing valuable guidance for personalized therapy for patients with pancreatic cancer.

Pancreatic adenocarcinoma pathology: changing "landscape"

Pancreatic cancer is a devastating disease. At time of diagnosis the disease is usually advanced and only a minority of patients are eligible for surgical resection. The overall 5-year survival is 6%. However, survival of patients with early stage pancreatic cancer is significantly better. To improve the prognosis of patients with pancreatic cancer, it is essential to diagnose and treat pancreatic cancer in the earliest stage. Prevention of pancreatic cancer by treating noninvasive precursor lesions just before they invade tissues can potentially lead to even better outcomes. Pancreatic carcinogenesis results from a stepwise progression in which accumulating genetic alterations drive neoplastic progression in well-defined precursor lesions, ultimately giving rise to an invasive adenocarcinoma. A thorough understanding of the genetic changes that drive pancreatic carcinogenesis can lead to identification of biomarkers for early detection and targets for therapy. Recent next-generation sequencing (NGS) studies have shed new light on our understanding of the natural history of pancreatic cancer and the precursor lesions that give rise to these cancers. Importantly, there is a significant window of opportunity for early detection and treatment between the first genetic alteration in a cell in the pancreas and development of full-blown pancreatic cancer. The current views on the pathology and genetics of pancreatic carcinogenesis that evolved from studies of pancreatic cancer and its precursor lesions are discussed in this review.

Clinicopathologic characteristics of 29 invasive carcinomas arising in 178 pancreatic mucinous cystic neoplasms with ovarian-type stroma: implications for management and prognosis

Information on the clinicopathologic characteristics of invasive carcinomas arising from mucinous cystic neoplasms (MCNs) is limited, because in many early studies they were lumped and analyzed together with noninvasive MCNs. Even more importantly, many of the largest prior studies did not require ovarian-type stroma (OTS) for diagnosis. We analyzed 178 MCNs, all strictly defined by the presence of OTS, 98% of which occurred in perimenopausal women (mean age, 47 y) and arose in the distal pancreas. Twenty-nine (16%) patients had associated invasive carcinoma, and all were female with a mean age of 53. Invasion was far more common in tumors with grossly visible intracystic papillary nodule formation ≥1.0 cm (79.3% vs. 8.7%, P=0.000) as well as in larger tumors (mean cyst size: 9.4 vs. 5.4 cm, P=0.006); only 4/29 (14%) invasive carcinomas occurred in tumors that were <5 cm; however, none were <3 cm. Increased serum CA19-9 level (>37 U/L) was also more common in the invasive tumors (64% vs. 23%, P=0.011). Most invasive carcinomas (79%) were of tubular type, and the remainder (5 cases) were mostly undifferentiated carcinoma (2, with osteoclast-like giant cells), except for 1 with papillary features. Interestingly, there were no colloid carcinomas; 2 patients had nodal metastasis at the time of diagnosis, and both died of disease at 10 and 35 months, respectively. While noninvasive MCNs had an excellent prognosis (100% at 5 y), tumors with invasion often had an aggressive clinical course with 3- and 5-year survival rates of 44% and 26%, respectively (P=0.000). The pT2 (>2 cm) invasive tumors had a worse prognosis than pT1 (≤2 cm) tumors (P=0.000), albeit 3 patients with T1a (<0.5 cm) disease also died of disease. In conclusion, invasive carcinomas are seen in 16% of MCNs and are mostly of tubular (pancreatobiliary) type; colloid carcinoma is not seen in MCNs. Serum CA19-9 is often higher in invasive carcinomas, and invasion is typically seen in OTS-depleted areas with lower progesterone receptor expression. Invasion is not seen in small tumors (<3 cm) and those lacking intracystic papillary (mural) nodules of ≥1 cm, thus making the current branch-duct intraductal papillary mucinous neoplasm management protocols also applicable to MCNs.

Mucinous Cystic Neoplasms of Pancreas

The purpose of this study was to investigate the actual management of mucinous cystic neoplasm (MCN) of the pancreas. A systematic review was performed in December 2009 by consulting PubMed MEDLINE for publications and matching the key words “pancreatic mucinous cystic neoplasm”, “pancreatic mucinous cystic tumor”, “pancreatic mucinous cystic mass”, “pancreatic cyst” and “pancreatic cystic neoplasm” to identify English language articles describing the diagnosis and treatment of the MCN of the pancreas. In total, 16,322 references ranging from January 1969 to December 2009 were analyzed and 77 articles were identified. No articles published before 1996 were selected because MCNs were not previously considered to be a completely autonomous disease. Definition, epidemiology, anatomopathological findings, clinical presentation, preoperative evaluation, treatment and prognosis were reviewed. MCNs are pancreatic mucin-producing cysts with a distinctive ovarian-type stroma localized in the body-tail of the gland and occurring in middle-aged females. The majority of MCNs are slow growing and asymptomatic. The prevalence of invasive carcinoma varies between 6% and 55%. Preoperative diagnosis depends on a combination of clinical features, tumor markers, computed tomography (CT), magnetic resonance imaging, endoscopic ultrasound with cyst fluid analysis and positron emission tomography-CT. Surgery is indicated for all MCNs.

Mucinous cystic neoplasm of the pancreas: is surgical resection recommended for all surgically fit patients?

BACKGROUND

Surgical removal of mucinous cystic neoplasms (MCNs) is usually recommended because of the risk of malignancy. However, increased experience of MCNs suggests that the incidence of invasion is lower than had been thought. This study was designed to establish more reasonable surgical indications for MCN through re-assessment using strict pathologic diagnostic criteria.

METHODS

Ninety-four patients who underwent surgical removal of MCNs at Seoul National University Hospital from 1991 to 2012 were retrospectively analyzed. Pathologic results were re-evaluated by an experienced pathologist. Medical records and radiologic images were reviewed to determine factors predicting malignancy.

RESULTS

Of the 94 patients, 4 were found to have intraductal papillary mucinous neoplasms (IPMNs). Of the 90 MCNs, 60 (66.7%) were low-grade, 21 (23.3%) were intermediate-grade, and 5 (5.5%) were high-grade dysplasias; and 4 (4.4%) were invasive carcinoma. Mural nodules on CT scan (p = 0.005) and abnormal serum CA19-9 concentration (p = 0.029) were significant predictors of malignancy. All MCNs less than 3 cm in size with normal serum tumor markers were benign and all malignant MCNs had cyst fluid CA19-9 over 10,000 units/ml. The five year disease specific survival rates were 98.8% for all patients and 75.0% for those with invasive MCNs.

CONCLUSION

MCNs had a low prevalence of malignancy. Regardless of the histological grade, long-term outcome was excellent. Therefore, in the absence of specific symptoms, surgery may not be indicated for MCNs <3 cm without mural nodules or elevated serum tumor markers. Validation by a prospective study with very careful design is needed.

Approach to cystic lesions of the pancreas

Cystic lesions of the pancreas are detected more frequently due to the improvement of imaging technologies. Their prevalence increases with age. In 95 % of cases, the spectrum of cystic neoplasia includes intraductal papillary mucinous neoplasia (IPMN), mucinous cystic neoplasia (MCN), serous cystic neoplasia, and solid pseudopapillary neoplasia (SPN). Diagnostic procedures aim to distinguish between neoplastic cystic and non-neoplastic cystic lesions as well as serous and mucinous lesions because of their different malignant potential. In most cases,cystic lesions are detected incidentally by computed tomography and magnetic resonance imaging (MRI) performed for other reasons. In our opinion, MRI/magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound (EUS) are complementary diagnostic procedures. In doubtful cases, cyst fluid analysis might be performed. The most frequent lesions are IPMNs. MRI/MRCP allows the detection of the number of cystic lesions, the relation to the main pancreatic duct, and the size of the lesion. EUS is superior to evaluate mural nodules. The relation to the main pancreatic duct can more easily appreciated with secretin MRI, MCN, SPN as well as main-duct type IPMN and BD-IPMN with "high-risk stigmata" for malignancy should be resected. Asymptomatic BD-IPMN without mural nodules, no main duct involvement, and a size less than 30 mm can be followed with a watchful waiting strategy.

Classification, morphology and molecular pathology of premalignant lesions of the pancreas

Over the past few years there have been substantial advances in our knowledge of premalignant lesions of the pancreas. Given the dismal prognosis of untreated pancreatic cancer, and the small proportion of patients who are operative candidates, an understanding of these premalignant lesions is essential for the development of strategies for early diagnosis and prevention. The 2010 WHO classification has added new entities, including intraductal tubular papillary neoplasms (ITPNs), and clarified the nomenclature and grading of previously recognised precursor lesions of pancreatic adenocarcinoma, such as intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs) and pancreatic intraepithelial neoplasia (PanIN). In particular, there has been an upsurge of interest in the natural history of IPMN, driven partly by improvements in imaging modalities and the consequent apparent increase in their incidence, and partly by recognition that subtypes based on location or histological appearance define groups with significantly different behaviours. In mid 2012 revised international guidelines for the classification and management of IPMNs and MCNs were published, although in several respects these guidelines represent a consensus view rather than being evidence-based. In recent years major advances in molecular technologies, including whole-exome sequencing, have significantly enhanced our knowledge of pancreatic premalignancy and have identified potentially highly specific diagnostic biomarkers such as mutations in GNAS and RNF43 that could be used to pre-operatively assess pancreatic cysts.

Surgical management and results for cystic neoplasms of pancreas

Backgrounds/Aims

The diagnosis for cystic neoplasm of pancreas is based on the morphologic criteria through imaging studies, but the pre- and postoperative diagnoses are often inconsistent. This study aims at the analysis of clinical characteristics and the results of surgical treatments.

Methods

A retrospective review was performed on 93 patients who have undergone surgery for pancreatic cystic diseases in our hospital from January 2001 to February 2013. Among them, 69 patients were confirmed as cystic neoplasms based on pathologic findings. Their clinical manifestations, diagnostic accuracy, surgical method and complications, pathologic findings were analyzed.

Results

Serous cystic neoplasm was the most common (n=22), followed by mucinous cystic neoplasm (n=18), intraductal papillary mucinous tumor (n=11), solid pseudopapillary tumor (n=9), neuroendocrine tumor (n=7), and cystic lymphangioma (n=2). The most common clinical symptom is abdominal pains (49.3%). Preoperative imaging studies were consistent with pathological findings in 72% of patients. Cystic fluid CEA levels of 400 ng/ml or more were reliable to detect mucin secreting tumors. Pancreatoduodenectomy was performed for 13 cases and the remaining 54 patients were treated with left-side pancreatectomy. Malignancy was found in 9 cases (13%) of mucin secreting tumors; 5 cases (27.8%) in mucinous cystic neoplasm and 4 cases (36.4%) in intraductal papillary mucinous tumor. Two of these survived without recurrences during the follow-up periods.

Conclusions

Exact treatment protocols for cystic neoplasm of pancreas are not decided because tumors are found with atypical forms. Surgical management is suggested for resectable tumors because a good prognosis can be expected with proper surgery if precancerous lesions are suspected at the time of discovery.

Prognosis of minimally invasive carcinoma arising in mucinous cystic neoplasms of the pancreas

Although patients with surgically resected noninvasive mucinous cystic neoplasms (MCNs) of the pancreas are cured, the behavior of surgically resected minimally invasive adenocarcinomas arising in MCN has not been well established. We report 16 surgically resected MCNs with minimal invasion defined as unifocal or multifocal microscopic invasive adenocarcinoma confined to the ovarian stroma of the MCN without capsular or pancreatic parenchymal invasion. Pathologic findings were correlated with patient demographics, type of surgery, and long-term follow-up. Our study included 15 women and 1 man ranging in age from 25 to 66 years. The patients were followed up for a mean of 48.6 months (range, 12 to 148 mo). The MCNs ranged in size from 3.5 to 25 cm and were all located in the body/tail of the gland. Lymphovascular invasion was not identified in any of the cases, and all lymph nodes were negative for tumor. Ten neoplasms had unifocal invasion, whereas 6 had multifocal invasion. Twelve of the neoplasms were partially submitted for microscopic examination, whereas 4 were submitted entirely. Only 1 of the 16 minimally invasive MCNs recurred, and that tumor had been lighlty sampled pathologically. Our study demonstrates that the majority of patients with minimally invasive adenocarcinoma arising in MCNs are cured by surgery, particularly if the neoplasms are completely examined histologically.

Nonmucinous cystadenomas of the pancreas with pancreatobiliary phenotype and ovarian-like stroma

Among 31 benign cystic neoplasms of the pancreas diagnosed as mucinous cystadenomas, we identified 9 (29%) cases of nonmucinous cystadenomas with a pancreatobiliary phenotype and an ovarian-like stroma. Although both cystic tumors belong to the same family, they should be separated because their epithelial lining and cyst fluid are different. The lining cells of the nonmucinous cystadenomas consisted of a single layer of cuboidal cells, similar to the epithelial cells of the normal pancreatic ducts, and were not dysplastic (90%-100% of the lining cells). The cyst fluid was described as serous or clear. The remaining 22 classical mucinous cystadenomas, lined predominantly by mucinous and foveolar epithelium, revealed focal pancreatobiliary epithelium in 86% of the cases, and 6 pancreatic invasive mucinous cystadenocarcinomas failed to show pancreatobiliary differentiation. We believe that these nonmucinous cystadenomas of the pancreas represent a distinctive subset of cystic neoplasms of the pancreas that probably have no malignant potential.

Endoscopic ultrasound guided fine needle aspiration for the diagnosis of pancreatic cystic neoplasms: a meta-analysis

BACKGROUND AND OBJECTIVES

Mucinous cystic neoplasms and intraductal papillary mucinous tumours have greater malignant potential than serous cystic neoplasms. EUS alone is inadequate for characterising these lesions but the addition of FNA may significantly improve diagnostic accuracy. The performance of EUS-FNA is highly variable in published studies.

AIM

To determine the diagnostic accuracy of EUS-FNA to differentiate mucinous versus non-mucinous cystic lesions with cyst fluid analysis for cytology and carcinoembryonic antigen (CEA) by performing a meta-analysis of published studies.

METHODS

Relevant studies were identified via structured database search and included if they used a reference standard of definitive surgical histology or clinical follow-up of at least 6 months. Data from selected studies were pooled to give summary sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio and Receiver Operating Characteristic (ROC) curve. Pre-defined subgroup analysis was performed.

RESULTS

Eighteen studies (published 2002-2011) were included, with a total of 1438 patients. For cytology, pooled sensitivity was 54(95%CI 49-59)% and specificity 93(90-95)%. The diagnostic odds ratio (DOR) was 13.3 (4.37-49.43), with I(2) of 77.1%. For CEA sensitivity was 63(59-67)% and specificity 88(83-91)%. The DOR was 10.76(6.29-18.41) with an I(2) of 25.4%. The diagnostic accuracy of EUS-FNA was enhanced in prospective studies and studies of <36 months duration. No impact of publication bias on our results was demonstrated.

CONCLUSIONS

Fine-needle aspiration has moderate sensitivity but high specificity for mucinous lesions. EUS-FNA, when used in conjunction with cross sectional imaging, is a useful diagnostic tool for the correct identification of mucinous cysts.

Pathology and Genetics of Pancreatic Neoplasms

This is a state-of-the-art review of the molecular genetics of pancreatic neoplasms. Although understanding of the molecular features underlying pancreatic neoplasms is still in its infancy, a strong emphasis on the relevance of these findings for the practicing surgical pathologist is provided. The application of molecular techniques has yielded a wealth of information that may soon enhance diagnostics, and will also lead to the development of safer, more effective targeted therapies. The pathologist will play a key role in integrating the current pathologic classification system with newly validated molecular markers.

Mucinous cystic neoplasms of the pancreas with ovarian stroma

BACKGROUNDS

Mucinous cystic neoplasms (MCNs) of the pancreas are rare, but have recently been increasing in incidence. The aim of this retrospective clinical study was to elucidate the clinicopathological features and prognosis of MCNs with ovarian stroma at a single centre.

METHODS

Using the presence of ovarian stroma as a requisite criterion for diagnosis of MCNs, the medical records of 47 surgically treated patients with MCNs from January 2004 to April 2011 were reviewed and classified according to the new 2010 World Health Organization classification.

RESULTS

Included were 37 cases of low-grade (78.7%), 4 intermediate-grade (8.5%) and 1 high-grade dysplasia (8.5%), and 5 cases of invasive carcinomas (10.6%). Patients were exclusively women (91.5%) with a mean age of 48.5 years. Most tumours were in the pancreatic body/tail (89.4%) with a mean size of 5.24 cm. More than half were asymptomatic. Findings associated with malignancy were presence of mural nodules (P < 0.001) and cyst wall calcifications (P = 0.017). All invasive MCNs were ≥5.0 cm or had mural nodules. No lymph node metastasis was seen in 20 cases of lymph nodes dissected. None of the 42 patients with non-invasive MCNs recurred after a mean follow-up of 25 months. However, two of five patients with invasive MCNs recurred, and one died within 2 years.

CONCLUSIONS

The prognosis of the resected non-invasive MCNs was excellent. Although resection should be considered for all cases, in low-risk MCNs (<5 cm and without nodules), nonradical resections (i.e. enucleations) are appropriate.

Preoperative gemcitabine and oxaliplatin in a patient with ovarian metastasis from pancreatic cystadenocarcinoma

We describe a case of clinical benefit and partial response with gemcitabine and oxaliplatin (GEMOX) in a young patient with ovarian metastasis from cystadenocarcinoma of the pancreas. A young woman complained of abdominal pain and constipation. Computed tomography (CT) and magnetic resonance imaging scans disclosed two bilateral ovarian masses with pancreatic extension. She underwent bilateral ovarian and womb resection. During surgery peritoneal carcinosis, a pancreatic mass and multiple abdominal lesions were found. The final diagnosis was mucinous pancreatic cystadenocarcinoma with ovarian and peritoneal metastases. She started chemotherapy with GEMOX (gemcitabine 1,000 mg/m(2)/d1 and oxaliplatin 100 mg/m(2)/d2 every 2 weeks). After 12 cycles of chemotherapy a CT scan showed reduction of the pancreatic mass. She underwent distal pancreatic resection, regional lymphadenectomy and splenectomy. Pathologic examination documented prominent fibrous tissue and few neoplastic cells with mucin-filled cytoplasm. Chemotherapy was continued with gemcitabine as adjuvant treatment for another 3 cycles. There is currently no evidence of disease. As reported in the literature, GEMOX is associated with an improvement in progression-free survival and clinical benefit in patients with advanced pancreatic cancer. This is an interesting case in whom GEMOX transformed inoperable pancreatic cancer into a resectable tumor.

A noninvasive mucinous cystic neoplasm with intermediate-grade dysplasia of the pancreas and extensive squamous metaplasia: a case report with clinicopathological correlation

Abstract

Squamous metaplasia presenting in noninvasive mucinous cystic neoplasm (MCN) of the pancreas is extremely rare. We described a case of 39-year-old Chinese female with a 5-year history of a slow growing mass in the left upper abdomen and an 18-month history of surgical incision exudation. The patient underwent cystojejunostomy, laparotomy and distal pancreatectomy consecutively because of the initial diagnosis of “pancreatic cyst”. The histological section showed columnar mucin-producing epithelium formed small papillary projections and extensively visible squamous metaplasia. Therefore the diagnosis of “noninvasive MCN with intermediate-grade dysplasia of the pancreas and extensive squamous metaplasia” was made finally. The squamous component of the pancreas may be derived from pluripotent stem cells, and may be in association with cystojejunostomy.

Virtual slides

The virtual slide(s) for this article can be found here http://www.diagnosticpathology.diagnomx.eu/vs/1322364365718540

[Precursor lesions of pancreatobiliary cancer]

Precursor lesions of pancreatobiliary cancer can be divided into cystic and flat lesions. Mucinous cystic neoplasm and intraductal papillary mucinous neoplasm (IPMN) comprise the cystic precursors in the pancreas, while intraductal papillary neoplasm (IPN) represents their counterpart in the bile duct system. There is an adenoma-carcinoma sequence in the cystic precursors arising from four different types of epithelia: pancreatobiliary, oncocytic, intestinal and gastric. These subtypes of IPMN/IPN are morphologically and immunohistochemically well characterised and show clinical and prognostic relevance: the gastric subtype is associated with the best prognosis, followed by the oncocytic and intestinal subtypes, while the pancreatobiliary subtype is characterized by adverse clinical behaviour. Pancreatic intraepithelial neoplasia (PanIN) and biliary intraepithelial neoplasia (BilIN) represent the flat precursors. PanIN are morphologically and biologically well defined. PanIN with lobulocentric atrophy has recently been described as a putative precursor of pancreatic cancer. Despite well defined morphological features in BilIN, the molecular alterations seen during early tumor progression in the biliary tract are poorly understood.

Precursor lesions in pancreatic cancer: morphological and molecular pathology

Pancreatic cancer has a dismal prognosis and is the fourth most common cause of cancer related death in Western societies. In large part this is due to its typically late presentation, usually as locally advanced or metastatic disease. Identification of the non-invasive precursor lesions to pancreatic cancer raises the possibility of surgical treatment or chemoprevention at an early stage in the evolution of this disease, when more amenable to therapeutic interventions. Precursor lesions to pancreatic ductal adenocarcinoma, in particular pancreatic intraepithelial neoplasia (PanIN), have been recognised under a variety of synonyms for over 50 years. Over the past decade our understanding of the morphology, biological significance and molecular aberrations of these lesions has grown rapidly and there is now a widely accepted progression model integrating the accumulated morphological and molecular observations. Further progress is likely to be accelerated by improved mouse models of pancreatic cancer and by insight into the cancer genome gained by the International Cancer Genome Consortium (ICGC), in which an Australian consortium is leading the pancreatic cancer initiative. This review also outlines the morphological and molecular features of the other two precursors of pancreatic ductal adenocarcinoma, i.e., intraductal papillary mucinous neoplasms and mucinous cystic neoplasms.

Islet autotransplantation after extended pancreatectomy for focal benign disease of the pancreas

BACKGROUND

Extended pancreatectomy is associated with the risk of surgical diabetes. Islet autotransplantation is successful in the prevention of diabetes after pancreas resection for chronic pancreatitis (CP), with insulin independence rates of 50% at 1 year. The aim of the present study is to demonstrate the safety and efficiency of islet autotransplantation after extended left pancreatectomy for benign disease.

METHODS

Between 1992 and 2009, 25 patients underwent extended pancreatectomy and islet autotransplantation for benign disease. Of these, 15 patients were operated for focal lesions located at the neck of the pancreas (14 benign tumors and 1 traumatic pancreatic section), the remainder being CP cases. After unequivocal diagnosis of benignity, the rest of the pancreas was processed and infused into the portal vein. Metabolic results were analyzed and isolation results were compared with those obtained from patients with CP or donors with brain death (DBD).

RESULTS

There was no mortality and a low morbidity (Streptococcus mitis bacteremia in 1 patient), no portal thrombosis or pancreatic fistula occurred. Median follow-up was 90 months. Actuarial patient survival was 100% at 10 years. Actuarial insulin independence was 94% at 10 years. All patients had positive basal and stimulated C-peptide levels and normal HbA1c. Mean islet yields were 5455 IEQ/gram vs. 1457 in CP (P=0.001) and 3738 in DBD (P=0.003).

CONCLUSIONS

Islet autotransplantation after extensive pancreatic resection for benign disease is a safe and successful procedure. Islet yields after isolation, which are equivalent to the live donor situation, are significantly better than those from DBD donors.

Pancreatic Cystic Tumors of Mucinous Type

This article presents the clinicopathologic characteristics and differential features of pancreatic mucinous tumors. These tumors, which correspond to the most frequent cystic neoplasms, are encountered with increasing frequency. They comprise the mucinous cystic neoplasms and the intraductal papillary mucinous neoplasms. These tumors are known to progress from dysplasia to invasive carcinoma. Thus, it appears important to distinguish them from other cystic neoplasms and non-neoplastic cysts.

Cystic precursors to invasive pancreatic cancer

Improvements in the sensitivity and quality of cross-sectional imaging have led to increasing numbers of patients being diagnosed with cystic lesions of the pancreas. In parallel, clinical, radiological, pathological and molecular studies have improved the systems for classifying these cysts. Patients with asymptomatic serous cystic neoplasms can be managed conservatively with regular monitoring; however, the clinical management of patients with intraductal papillary mucinous neoplasms and mucinous cystic neoplasms is far more challenging, as it is difficult to determine whether these lesions will progress to malignancy. Fortunately, prospective studies have helped to establish that proposed clinical and radiological criteria (the Sendai guidelines) can be used to guide the care of patients with cystic lesions of the pancreas. Despite this progress in imaging and clinical guidelines, sensitive and specific tests have not yet been developed that can reliably predict the histology and biological properties of a cystic lesion. Such biomarkers are urgently needed, as noninvasive precursors of pancreatic cancer are curable, while the vast majority of invasive pancreatic adenocarcinomas are not.

Primary pancreatic cystic neoplasms revisited: part II. Mucinous cystic neoplasms

Mucinous cystic neoplasms (MCNs) of the pancreas represent one of the most common primary pancreatic cystic neoplasms, accounting for approximately half of these cases. MCNs are observed almost exclusively in women, and most commonly are located in the body/tail of the pancreas. In contrast to SCNs, MCNs have malignant potential. Proliferative changes (hyperplasia with or without atypia, borderline changes, non-invasive or carcinomas in-situ, and invasive carcinomas) can often be observed within the same neoplasm. Several risk factors for the presence of underlying malignancy within an MCN have recently been recognized. Cross-sectional imaging is of key importance for the diagnostic evaluation of patients with a cystic pancreatic lesion. Cyst fluid examination (cytology, biochemical/genetic analysis) is possible by using fine needle aspiration of the MCN, usually under endoscopic guidance, and may provide useful information for the differential diagnosis. Since MCNs have malignant potential, surgical resection is the treatment of choice.

Management of mucinous cystic neoplasms of the pancreas

The purpose of this study was to investigate the actual management of mucinous cystic neoplasm (MCN) of the pancreas. A systematic review was performed in December 2009 by consulting PubMed MEDLINE for publications and matching the key words “pancreatic mucinous cystic neoplasm”, “pancreatic mucinous cystic tumour”, “pancreatic mucinous cystic mass”, “pancreatic cyst”, and “pancreatic cystic neoplasm” to identify English language articles describing the diagnosis and treatment of the mucinous cystic neoplasm of the pancreas. In total, 16 322 references ranging from January 1969 to December 2009 were analysed and 77 articles were identified. No articles published before 1996 were selected because MCNs were not previously considered to be a completely autonomous disease. Definition, epidemiology, anatomopathological findings, clinical presentation, preoperative evaluation, treatment and prognosis were reviewed. MCNs are pancreatic mucin-producing cysts with a distinctive ovarian-type stroma localized in the body-tail of the gland and occurring in middle-aged females. The majority of MCNs are slow growing and asymptomatic. The prevalence of invasive carcinoma varies between 6% and 55%. Preoperative diagnosis depends on a combination of clinical features, tumor markers, computed tomography (CT), magnetic resonance imaging, endoscopic ultrasound with cyst fluid analysis, and positron emission tomography-CT. Surgery is indicated for all MCNs.