Glucose and lactate levels are lower in EUS-aspirated cyst fluid of mucinous vs non-mucinous pancreatic cystic lesions

BACKGROUND

Distinguishing mucinous (M) pancreatic cystic neoplasms (PCNs) from non-mucinous (NM) is challenging but crucial. Low intracystic glucose level has shown diagnostic tool promise, however further investigation is needed to understand metabolic processes.

AIMS

To compare the diagnostic accuracy of intracystic glucose and CEA levels in a large cohort and explore lactate levels as potential marker.

METHODS

PCNs≥15 mm which underwent EUS-fine needle aspiration were prospectively enrolled. Glucose, CEA and lactate levels were measured. Diagnostic accuracy for M-PCN diagnosis was evaluated using surgical/cytology reports or multidisciplinary evaluations.

RESULTS

169 PCNs were included (64 % M-PCNs). Median intracystic glucose was significantly lower in M-PCNs (1 mg/dL) compared to NM-PCNs (101 mg/dL); mean intracystic CEA was significantly higher in M-PCNs (152.5 ng/mL) compared to NM-PCNs (0.3 ng/mL). ROC curve analysis revealed best glucose cut-off ≤58 mg/dL (accuracy 93.5 %) and CEA cut-off >2.5 ng/mL (accuracy 90.5 %) for M-PCNs. Intracystic lactates were significantly lower in M-PCNs correlating directly with glucose. Single glucose dosage evidenced best diagnostic accuracy respect markers combination.

CONCLUSION

Intracystic glucose demonstrated high diagnostic utility for M-PCNs differentiation, surpassing CEA. Lactate levels correlated with glucose, suggesting their uptake by M-PCNs cells. These findings contribute to a better metabolic landscape understanding glucose use as diagnostic marker.

A large-area organic transistor with 3D-printed sensing gate for noninvasive single-molecule detection of pancreatic mucinous cyst markers

Early diagnosis in a premalignant (or pre-invasive) state represents the only chance for cure in neoplastic diseases such as pancreatic-biliary cancer, which are otherwise detected at later stages and can only be treated using palliative approaches, with no hope for a cure. Screening methods for the purpose of secondary prevention are not yet available for these cancers. Current diagnostic methods mostly rely on imaging techniques and conventional cytopathology, but they do not display adequate sensitivity to allow valid early diagnosis. Next-generation sequencing can be used to detect DNA markers down to the physical limit; however, this assay requires labeling and is time-consuming. The additional determination of a protein marker that is a predictor of aggressive behavior is a promising innovative approach, which holds the potential to improve diagnostic accuracy. Moreover, the possibility to detect biomarkers in blood serum offers the advantage of a noninvasive diagnosis. In this study, both the DNA and protein markers of pancreatic mucinous cysts were analyzed in human blood serum down to the single-molecule limit using the SiMoT (single-molecule assay with a large transistor) platform. The SiMoT device proposed herein, which exploits an inkjet-printed organic semiconductor on plastic foil, comprises an innovative 3D-printed sensing gate module, consisting of a truncated cone that protrudes from a plastic substrate and is compatible with standard ELISA wells. This 3D gate concept adds tremendous control over the biosensing system stability, along with minimal consumption of the capturing molecules and body fluid samples. The 3D sensing gate modules were extensively characterized from both a material and electrical perspective, successfully proving their suitability as detection interfaces for biosensing applications. KRAS and MUC1 target molecules were successfully analyzed in diluted human blood serum with the 3D sensing gate functionalized with b-KRAS and anti-MUC1, achieving a limit of detection of 10 zM and 40 zM, respectively. These limits of detection correspond to (1 ± 1) KRAS and (2 ± 1) MUC1 molecules in the 100 μL serum sample volume. This study provides a promising application of the 3D SiMoT platform, potentially facilitating the timely, noninvasive, and reliable identification of pancreatic cancer precursor cysts.

Humoral Predictors of Malignancy in IPMN: A Review of the Literature

Pancreatic cystic lesions are increasingly detected in cross-sectional imaging. Intraductal papillary mucinous neoplasm (IPMN) is a mucin-producing subtype of the pancreatic cyst lesions arising from the pancreatic duct system. IPMN is a potential precursor of pancreatic cancer. The transformation of IPMN in pancreatic cancer is progressive and requires the occurrence of low-grade dysplasia, high-grade dysplasia, and ultimately invasive cancer. Jaundice, enhancing mural nodule >5 mm, main pancreatic duct diameter >10 mm, and positive cytology for high-grade dysplasia are considered high-risk stigmata of malignancy. While increased levels of carbohydrate antigen 19-9 (CA 19-9) (>37 U/mL), main pancreatic duct diameter 5-9.9 mm, cyst diameter >40 mm, enhancing mural nodules <5 mm, IPMN-induced acute pancreatitis, new onset of diabetes, cyst grow-rate >5 mm/year are considered worrisome features of malignancy. However, cross-sectional imaging is often inadequate in the prediction of high-grade dysplasia and invasive cancer. Several studies evaluated the role of humoral and intra-cystic biomarkers in the prediction of malignancy in IPMN. Carcinoembryonic antigen (CEA), CA 19-9, intra-cystic CEA, intra-cystic glucose, and cystic fluid cytology are widely used in clinical practice to distinguish between mucinous and non-mucinous cysts and to predict the presence of invasive cancer. Other biomarkers such as cystic fluid DNA sequencing, microRNA (mi-RNA), circulating microvesicles, and liquid biopsy are the new options for the mini-invasive diagnosis of degenerated IPMN. The aim of this study is to review the literature to assess the role of humoral and intracystic biomarkers in the prediction of advanced IPMN with high-grade dysplasia or invasive carcinoma.

Role of Ancillary Testing on Endoscopic US-Guided Fine Needle Aspiration Samples from Cystic Pancreatic Neoplasms

Pancreatic cysts are increasingly detected on imaging studies. Accurate determination of the cyst type is important to provide appropriate care for the patients. It is also very clear that not one single modality can provide adequate diagnostic information. A multidisciplinary approach is the key to the diagnosis of pancreatic cysts. In this setting, the role of ancillary testing, which includes biochemical testing (carcinoembryonic antigen and amylase levels in the cyst), molecular testing (e.g., KRAS, GNAS, VHL, and CTNB1), and/or immunohistochemical tests are very important to obtain an accurate diagnosis. This review will discuss helpful ancillary tests in common pancreatic cyst neoplasms and how to approach the diagnosis of pancreatic cysts.

Pancreatic endometrial cyst mimics mucinous cystic neoplasm of the pancreas

Pancreatic cysts include a variety of benign, premalignant, and malignant lesions. Endometrial cysts in the pancreas are exceedingly rare lesions that are difficult to diagnose pre-operatively. This report describes the findings in a 43-year-old patient with a recent episode of acute pancreatitis who presented with a large cyst in the tail of the pancreas. Imaging demonstrated a loculated pancreatic cyst, and cyst fluid aspiration revealed an elevated amylase and carcinoembryonic antigen. The patient experienced an interval worsening of abdominal pain, fatigue, diarrhea, and a 15-pound weight loss 3 mo after the initial episode of pancreatitis. With concern for a possible pre-malignant lesion, the patient underwent a laparoscopic distal pancreatectomy with splenectomy, which revealed a 16 cm × 12 cm × 4 cm lesion. Final histopathology was consistent with an intra-pancreatic endometrial cyst. Here we discuss the overlapping imaging and laboratory features of pancreatic endometrial cysts and mucinous cystic neoplasms of the pancreas.

Role of biochemistry and cytological analysis of cyst fluid for the differential diagnosis of pancreatic cysts: A retrospective cohort study

BACKGROUND

Management of pancreatic cysts is based on neoplastic-nonneoplastic discrimination. Endoscopic ultrasound (EUS) enables to differentiate neoplastic-nonneoplastic lesions and also allows fine-needle aspiration (FNA). In this study, we aim to assess feasibility and clinical relevance of cytological and biochemical analysis in differential diagnosis of cystic pancreatic lesions in patients who had undergone endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) due to pancreatic cysts.

METHODS

Participants were 96 patients who had undergone EUS-FNA for differential diagnosis of pancreatic cysts. Pancreatic cysts were classified as benign-mucinous, nonmucinous, and malignant according to patient history, physical examination, EUS appearance, and cystic fluid assessment. Tumor markers (CEA, CA(cancer antigens) 72.4, CA 19-9) , amylase, lipase and cytological assesment were compared between 3 different groups. Receiver-operating characteristics (ROC) curves were constructed to identify appropriate cut-off values.

RESULTS

Fluid CEA and CA 72.4 levels for benign-mucinous and malignant cysts were significantly higher than for nonmucinous cysts (P ≤ 0.04). A cut-off CEA level of 207 ng/mL differentiated mucinous etiology with a sensitivity of 72.7%, specificity of 97.7%, and accuracy of 89.5%. The sensitivity, specificity, and accuracy of the CA 72.4 cut-off level of 3.32 ng/mL were 80%, 69.5%, and 73.6%, respectively.

CONCLUSION

Cyst fluid CEA and CA 72.4 levels have a high accuracy in discriminating mucinous from nonmucinous cysts. When combined with cytology their accuracy rate increases.

A Gastric Glycoform of MUC5AC Is a Biomarker of Mucinous Cysts of the Pancreas

Molecular indicators to specify the risk posed by a pancreatic cyst would benefit patients. Previously we showed that most cancer-precursor cysts, termed mucinous cysts, produce abnormal glycoforms of the proteins MUC5AC and endorepellin. Here we sought to validate the glycoforms as a biomarker of mucinous cysts and to specify the oligosaccharide linkages that characterize MUC5AC. We hypothesized that mucinous cysts secrete MUC5AC displaying terminal N-acetylglucosamine (GlcNAc) in either alpha or beta linkage. We used antibody-lectin sandwich assays to detect glycoforms of MUC5AC and endorepellin in cyst fluid samples from three independent cohorts of 49, 32, and 66 patients, and we used monoclonal antibodies to test for terminal, alpha-linked GlcNAc and the enzyme that produces it. A biomarker panel comprising the previously-identified glycoforms of MUC5AC and endorepellin gave 96%, 96%, and 87% accuracy for identifying mucinous cysts in the three cohorts with an average sensitivity of 92% and an average specificity of 94%. Glycan analysis showed that MUC5AC produced by a subset of mucinous cysts displays terminal alpha-GlcNAc, a motif expressed in stomach glands. The alpha-linked glycoform of MUC5AC was unique to intraductal papillary mucinous neoplasms (IPMN), whereas terminal beta-linked GlcNAc was increased in both IPMNs and mucinous cystic neoplasms (MCN). The enzyme that synthesizes alpha-GlcNAc, A4GNT, was expressed in the epithelia of mucinous cysts that expressed alpha-GlcNAc, especially in regions with high-grade dysplasia. Thus IPMNs secrete a gastric glycoform of MUC5AC that displays terminal alpha-GlcNAc, and the combined alpha-GlcNAc and beta-GlcNAc glycoforms form an accurate biomarker of mucinous cysts.

Serous Cystadenoma of the Pancreas: Potentials and Pitfalls of a Preoperative Cytopathologic Diagnosis

OBJECTIVES

Pancreatic serous cystadenomas (SCAs) are benign tumors. Technological advances in imaging have led to increased recognition of asymptomatic pancreatic cysts, consequently increasing the demand for cytomorphologic evaluations of cyst fluid.

STUDY DESIGN

A retrospective search through the pathology archives over an 11-year period was performed to identify SCAs from pancreatectomy specimens with a presurgical pancreatic EUS-guided fine-needle aspiration (FNA).

RESULTS

Fifty-one FNAs were identified. The average patient age was 59.9 years and 34 (67%) were female. Thirty-five (69%) of the SCAs were located in the body or tail of the pancreas. SCAs ranged in size from 1.3 to 8.0 cm (mean 4.9). On imaging, features suggestive of SCA were seen in 7 (14%) cases. The cytologic diagnoses were as follows: SCA in 5 (10%) cases, suspicious for mucin-producing neoplastic cyst in 4 (8%), pseudocyst in 4 (8%), and benign ductal and/or acinar epithelium, not otherwise specified in 24 (47%). Additionally, 14 (27%) cases were deemed nondiagnostic.

CONCLUSIONS

A cytopathologic diagnosis of SCA on FNA is extremely difficult. The salient cytomorphologic features for identifying SCAs included scant cellularity, a mostly clear background, absence of extracellular mucin, hemosiderin-laden macrophages, and loose fragments of cuboidal cells with a notable absence of necrosis, atypia, and mitoses.

Bullous pemphigoid associated with a lymphoepithelial cyst of the pancreas

Bullous pemphigoid (BP) is an acquired, autoimmune, subepidermal blistering disorder. A possible paraneoplastic association has been suggested; however, debate remains regarding the precise relationship of these neoplasms with BP. We present a case of recalcitrant BP in a 67-year-old man with a pancreatic neoplasm that was found to be a lymphoepithelial cyst. Immunoperoxidase staining of the cyst demonstrated C₃d along the basement membrane of the stratified squamous epithelium, suggesting that the BP may have involved the lymphoepithelial cyst itself. Shortly after excision of the cyst, BP rapidly resolved without any immunosuppressive treatment, raising the possibility that the immunologic process involving the lymphoepithelial cyst of the pancreas was the inciting factor for the patient's cutaneous disease. Although rare, some cases of BP may be a paraneoplastic process. A thorough screening via patient history and directed laboratory studies may be warranted in recalcitrant cases.

Impact of next-generation sequencing on the clinical diagnosis of pancreatic cysts

BACKGROUND AND AIMS

The value of next-generation sequencing (NGS) of pancreatic cyst fluid relative to the clinical and imaging impression has not been well-studied. The aim of this study was to assess the impact of NGS on the clinical diagnosis from imaging and carcinoembryonic antigen (CEA) and thus the management of pancreatic cysts.

METHODS

Ninety-two pancreatic cyst fluids from 86 patients were analyzed by cytology, CEA, and targeted NGS. Cysts were classified by imaging as nonmucinous, mucinous, or not specified. NGS results were compared with the imaging impression stratified by CEA and cytology.

RESULTS

NGS impacted the clinical diagnosis by defining a cyst as mucinous in 48% of cysts without elevated CEA levels. The VHL gene in 2 intraductal papillary mucinous neoplasms (IPMNs) supported a serous cystadenoma. Twenty percent of cysts that were nonmucinous by imaging were mucinous by NGS. Of the 14 not-specific cysts, CEA levels were not elevated in 12 (86%), and NGS established a mucinous etiology in 3 (25%). A KRAS or GNAS mutation supported an IPMN with nonmucinous CEA in 71%. A KRAS mutation reclassified 19% of nonneoplastic cysts with nonmucinous CEA as mucinous. Seven cyst fluids (8%) had either a TP53 mutation or loss of CDKN2A or SMAD4 in addition to KRAS and/or GNAS mutations; 5 of 7 (71%) were clinically malignant, and high-grade cytology was detected in all 5. Overall, CEA was more specific for a mucinous etiology (100%), but NGS was more sensitive (86% vs 57%).

CONCLUSIONS

NGS of pancreatic cyst fluid impacts clinical diagnosis and patient management by defining, supporting, or changing the clinical diagnosis based on imaging and CEA. NGS was most valuable in identifying mucinous cysts with nonmucinous CEA. An added benefit is the potential to detect mutations late in the progression to malignancy that may increase the risk classification of the cyst based on imaging and cytology.

Carboxyl-ester lipase maturity-onset diabetes of the young is associated with development of pancreatic cysts and upregulated MAPK signaling in secretin-stimulated duodenal fluid

Carboxyl-ester lipase (CEL) maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes and pancreatic exocrine dysfunction due to mutations in the CEL gene encoding CEL. The pathogenic mechanism for diabetes development is unknown. Since CEL is expressed mainly in pancreatic acinar cells, we asked whether we could find structural pancreatic changes in CEL-MODY subjects during the course of diabetes development. Furthermore, we hypothesized that the diseased pancreas releases proteins that are detectable in pancreatic fluid and potentially reflect activation or inactivation of disease-specific pathways. We therefore investigated nondiabetic and diabetic CEL-mutation carriers by pancreatic imaging studies and secretin-stimulated duodenal juice sampling. The secretin-stimulated duodenal juice was studied using cytokine assays, mass spectrometry (MS) proteomics, and multiplexed MS-based measurement of kinase activities. We identified multiple pancreatic cysts in all eight diabetic mutation carriers but not in any of the four nondiabetic mutation carriers or the six healthy controls. Furthermore, we identified upregulated mitogen-activated protein kinase (MAPK) target proteins and MAPK-driven cytokines and increased MAPK activity in the secretin-stimulated duodenal juice. These findings show that subjects with CEL-MODY develop multiple pancreatic cysts by the time they develop diabetes and that upregulated MAPK signaling in the pancreatic secretome may reflect the pathophysiological development of pancreatic cysts and diabetes.

GeLC-MRM quantitation of mutant KRAS oncoprotein in complex biological samples

Tumor-derived mutant KRAS (v-Ki-ras-2 Kirsten rat sarcoma viral oncogene) oncoprotein is a critical driver of cancer phenotypes and a potential biomarker for many epithelial cancers. Targeted mass spectrometry analysis by multiple reaction monitoring (MRM) enables selective detection and quantitation of wild-type and mutant KRAS proteins in complex biological samples. A recently described immunoprecipitation approach (Proc. Nat. Acad. Sci.2011, 108, 2444-2449) can be used to enrich KRAS for MRM analysis, but requires large protein inputs (2-4 mg). Here, we describe sodium dodecyl sulfate-polyacrylamide gel electrophoresis-based enrichment of KRAS in a low molecular weight (20-25 kDa) protein fraction prior to MRM analysis (GeLC-MRM). This approach reduces background proteome complexity, thus, allowing mutant KRAS to be reliably quantified in low protein inputs (5-50 μg). GeLC-MRM detected KRAS mutant variants (G12D, G13D, G12V, G12S) in a panel of cancer cell lines. GeLC-MRM analysis of wild-type and mutant was linear with respect to protein input and showed low variability across process replicates (CV = 14%). Concomitant analysis of a peptide from the highly similar HRAS and NRAS proteins enabled correction of KRAS-targeted measurements for contributions from these other proteins. KRAS peptides were also quantified in fluid from benign pancreatic cysts and pancreatic cancers at concentrations from 0.08 to 1.1 fmol/μg protein. GeLC-MRM provides a robust, sensitive approach to quantitation of mutant proteins in complex biological samples.

Mature cystic teratoma of the pancreas. Case report and review of the literature of a rare pancreatic cystic lesion

CONTEXT

Pancreatic cystic lesions are increasingly recognized and comprise different pathological entities. The management of these lesions is challenging, because of inadequate preoperative histological diagnosis. Among this family of lesions, mature cystic teratomas are an extremely rare finding.

CASE REPORT

We present the case of a 61-year-old man with a mature cystic teratoma of the pancreas' uncinate process, incidentally discovered at diagnostic imaging.

CONCLUSIONS

This case highlights the difficulty to obtain a preoperative diagnosis of this pathological entity and the need of increased awareness about mature cystic teratoma when examining a pancreatic cystic lesion.

Pancreatic cystic lesions without overt cytologic atypia: proposed diagnostic categories for endoscopic ultrasound-guided fine-needle aspiration cytology with utilization of fluid carcinoembryonic antigen level

OBJECTIVES

It was the aim of this study to examine pancreatic cyst cases that lack markedly atypical or malignant epithelium on endoscopic ultrasound-guided fine-needle aspirations.

STUDY DESIGN

We conducted a retrospective case review study, including 24 cases that were either acellular or lacked cytologic atypia and were subsequently resected. The cases were retrospectively divided into 3 categories: (1) non-diagnostic, (2) cyst contents only, and (3) cyst contents with bland-appearing epithelium. The cyst contents were subdivided into mucinous and non-mucinous types. The cytologic diagnoses were correlated with cyst fluid carcinoembryonic antigen (CEA) levels and subsequent histologic diagnoses.

RESULTS

Category 1 comprised 4 cases: 2 cases (CEA >800 ng/ml) with mucin-producing neoplasms and 2 cases (CEA not determined) with microcystic serous cystadenomas. Category 2 included 4 cases with non-mucinous and 4 with mucinous contents. In the first subgroup, 2 cases (CEA >800 ng/ml) showed mucinous cystic neoplasms and 2 cases (CEA negligible or not determined) pseudocysts. In the second subgroup, there were 3 cases with neoplastic mucinous cysts (1 CEA >800 ng/ml, 2 not determined) and 1 case with a lymphoepithelial cyst with mucinous metaplasia (CEA >800 ng/ml). Almost all cases (10/11) in category 3 had neoplastic mucinous cysts regardless of the CEA levels.

CONCLUSIONS

The proposed 3 cytologic categories of pancreatic cystic lesion combined with cyst fluid CEA levels provide useful clinical information.

CT attenuation of unilocular pancreatic cystic lesions to differentiate pseudocysts from mucin-containing cysts

CONTEXT

There is extensive overlap among the imaging characteristics of pseudocyst, mucinous cystic neoplasm (MCN) and side branch intraductal papillary mucinous neoplasm (IPMN) on CT images.

OBJECTIVE

The purpose of this study was to evaluate the usefulness of attenuation measurement in differentiating pseudocysts from MCN and IPMN of pancreas on CT images.

PATIENTS

Seventy-five pathologically proven unilocular pancreatic cysts including 31 pseudocysts, 29 MCN and 15 IPMN imaged with multidetector computed tomography (MDCT) before resection were evaluated.

MAIN OUTCOME MEASURES

Attenuation values were measured by conventional region of interest (ROI) method.

DESIGN

Attenuation values (in Hounsfield unit, HU) were compared between the cyst pathologies. Receiver operating characteristic (ROC) curve analysis was performed to obtain the best attenuation threshold between mucin-containing cysts and pseudocysts. Correlation between attenuation values and cyst size was assessed.

RESULTS

Maximum transaxial diameters of pseudocysts (4.5 cm), MCNs (3.7 cm) and IPMNs (4.0 cm) were comparable (P=0.919). Mean attenuation was 18.9 HU, 13.0 HU and 11.4 HU for pseudocyst, MCNs and IPMNs, respectively. Attenuations were significantly higher in pseudocysts versus mucin-containing (MCN+IPMN) cysts (P=0.001) and comparable between MCNs and IPMNs (P=0.390). ROC curve showed 14.5 HU the best cut-off (accuracy: 73.5%) for differentiating pseudocysts from mucin-containing cysts (P<0.001). Pancreatic cyst attenuation measurement did not significantly correlate with cyst size (r=-0.03, P=0.772).

CONCLUSION

Attenuation measurement may help in differentiating pseudocysts from unilocular mucin-containing simple cysts of the pancreas on CT images.

Pancreatic cyst aspirate CEA levels: two's the charm

CONTEXT

Pancreatic cysts are increasingly detected incidentally, many of which are premalignant. Despite EUS-FNA and CEA level measurement, the diagnosis of a premalignant cyst may remain uncertain.

CASE REPORT

We report two cases of incidentally found pancreatic cysts where initial EUS-FNA cyst aspirates yielded thin fluid with very low CEA levels. Repeat aspirations one year later revealed markedly different results (slightly viscous fluid with significantly elevated CEA levels) which prompted surgical resection in both cases. Final surgical pathology revealed mucinous cystic neoplasms.

CONCLUSION

Pancreatic cyst fluid CEA levels may increase over time, possibly due to neoplastic progression. A heightened index of suspicion for a neoplastic cyst should remain in the appropriate patient population, despite conflicting data. In cases of initial low aspirate CEA levels, we recommend a repeat EUS-FNA at a later date to exclude a premalignant lesion.

Syndecan-1 and tenascin expression in cystic tumors of the pancreas

CONTEXT

Since benign and malignant mucin-producing tumors of the pancreas may be difficult to distinguish from each other; preoperative methods for differential diagnosis would reduce unnecessary surgery.

OBJECTIVE

To compare syndecan-1 and tenascin immunoexpression in benign and malignant cystic pancreatic tumors.

DESIGN

We used immunohistochemical staining for syndecan-1 and tenascin antibodies in tumor tissue samples.

SETTING

Helsinki University Central Hospital.

PATIENTS

Tissue material came from 33 patients undergoing surgery from 1979 to 2005 for cystic pancreatic tumors.

RESULTS

A statistically significant difference appeared in syndecan-1 expression between benign (mucinous cystic neoplasms and intraductal papillary mucinous neoplasms) and mucinous carcinomas, but there was no significant difference in tenascin immunoexpression between these tumor groups.

CONCLUSION

Our findings suggest that low syndecan-1 expression might serve as a predictive factor for malignancy in cystic tumors of the pancreas.

Endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration with cyst fluid analysis in pancreatic cystic neoplasms

BACKGROUND/AIMS

Pancreatic cystic neoplasms represent a heterogeneous group of tumors with varied malignant potential. The aim of this prospective study was to evaluate EUS, EUS-FNA and cyst fluid analysis in distinguishing serous cystadenomas (SCA) and mucinous cystic neoplasms (MCN).

METHODOLOGY

Twelve patients with SCA (4 men, 8 women, mean age 58), 16 with MCN (3 men, 13 women, mean age 53) and 10 pancreatic non-tumorous cysts as controls (1 man, 9 women, mean age 43) were investigated by EUS-FNA from January 2003 to February 2006. Cyst fluid evaluation was done for cytology, amylase, CEA, CA 19-9, CA 72-4 and CA 15-3 (RIA). The final diagnosis was based on surgery & histology (14 patients) and/or follow-up after EUS-FNA (mean 15 months).

RESULTS

In the MCN-group 13 mucinous cystadenomas, 2 cystadenocarcinomas and 1 malignant IPMT were found. EUS-FNA results: cytology (including staining for mucin) was diagnostic in 2/12 SCA (17%), 10/16 MCN (63%) and negative in all controls. Fluid CEA in MCN-group (mean 9487, 95%CI 0-23637) was significantly higher compared both with SCA-group (mean 22, 95%CI 0-54, p<0.001) and controls (mean 4, 95%CI 0.5-8, p<0.001). Similar results were found in fluid CA72-4 and fluid CA19-9. Accuracy of EUS-FNA with final diagnosis was 93%.

CONCLUSIONS

EUS-FNA with cyst fluid CEA, CA72-4, CA19-9 and cytology are useful tools in differentiating SCA, MCN and non-tumorous cysts.

A comparative analysis of pancreas cyst fluid CEA and histology with DNA mutational analysis in the detection of mucin producing or malignant cysts

CONTEXT

The main objective of pancreatic cyst fluid analysis is to differentiate mucin-producing or malignant cysts from other cysts which have a benign course. K-ras-2 point mutation and at least two mutations of allelic imbalance or loss of heterozygosity with good quality DNA has been suggested to predict mucinous cystic neoplasm (MCN). Elevated carcinogenic embryonic antigen (CEA) level in cyst fluid has also been shown to be predictive of mucinous or malignant cysts.

OBJECTIVE

Identify the clinical impact of DNA mutational analysis of pancreatic cyst fluid with its correlation to cyst fluid chemistry and histologic analysis.

PATIENTS

This retrospective analysis included all consecutive patients with pancreatic cysts who presented for evaluation by endoscopic ultrasound (EUS) with fine needle aspiration (FNA) over an 18 month period until November 2007.

MAIN OUTCOME MEASURES

DNA analysis performed by Pathfinder TG (RedPath Integrated Pathology, Inc., Pittsburgh, PA, USA) and fluid CEA exceeding 192 ng/dL were used to suggest mucinous or malignant cysts. These parameters were compared to surgical histology or cytopathology of FNA specimens.

RESULTS

Twenty-seven consecutive patients with cysts had samples submitted for DNA analysis which included 15 men and 12 women (mean age 62.8 and 61.3 years, respectively). In 20 patients, all parameters including cyst fluid, DNA analysis, and histology were available for comparison. Consistent findings were seen in 7/20 (35%) in which all parameters suggested negative benign findings. CEA level was elevated in 7 patients of which 4 had mucinous or malignant histology. In the remaining 13 patients with low CEA levels, 11 had negative histology. The sensitivity and specificity of CEA based on these results was 66% and 78.6% respectively. The positive predictive value (PPV) of CEA was 57% and the negative predictive value (NPV) was 84.6%. K-ras-2 mutation was detected in 3 patients, absent in 17 patients and falsely negative in 4 cases based on histology. The sensitivity and specificity were 33% and 92.6% respectively. The PPV was 66% and NPV was 76%. Detection of loss of heterozygosity mutations was noted in 7 patients, of which 4 were falsely positive. In the remaining 13 patients, 3 were falsely negative. The sensitivity and specificity were 50% and 71% respectively. The PPV was 42.9% and NPV was 76.9%. In a group of 6 patients with available surgical histology demonstrating mucin-producing or malignant cysts, fluid CEA level had a sensitivity of 66.7%. However, K-ras-2 and loss of heterozygosity mutational analysis had a much lower sensitivity at 33% and 50% respectively.

CONCLUSIONS

Consistency in histology, CEA levels, and K-ras-2 and loss of heterozygosity mutations was seen in only 35% of cases, all of which were benign cysts. In the detection of malignant cysts, elevated CEA levels were more predictive of histology in comparison to K-ras-2 or loss of heterozygosity mutations. Additionally, false positivity of loss of heterozygosity mutations was noted to be considerably higher than K-ras-2 mutations or even fluid CEA levels. These findings suggest that DNA mutation analysis should not be used routinely but rather selectively in the evaluation of pancreatic cysts.

Squamoid cyst of pancreatic ducts: A distinct type of cystic lesion in the pancreas

The clinicopathologic features of a hitherto unrecognized cystic tumor of the pancreas are documented, and its possible relationship to a more common incidental microscopic lesion is analyzed. Six patients (3 men and 3 women) had undergone resection specifically for this cyst type. The mean age of the patients was 63 years (range 52 to 79 y) and the mean size of the tumors was 2.6 cm (median 1.5, range 0.8 to 9 cm). The cysts had variable lining ranging from attenuated, flat squamoid cells to transitional, to stratified squamous without keratinization (no granular layer). The cells forming the basal/parabasal region expressed p63 (transitional/squamous cell marker, not detected in any normal pancreas or nonsquamous neoplasia) and the surface cells were positive for MUC 1 and MUC 6 (markers present in intercalated duct cells), and negative for GLUT-1 (consistent marker of serous adenomas). The lesions appeared to be unilocular cystic dilatation of the ducts that typically contained distinctive muco-proteinaceous acidophilic acinar secretions forming concretions, confirming their communication with the acinar system, and suggesting a localized obstruction in their pathogenesis (a form of "retention" cyst). A thin fibrous wall devoid of any lymphoid tissue separated the cysts from unremarkable parenchyma. There was no evidence of pancreatitis (fibrosis or inflammation). Separately, 110 pancreata resected for various reasons were analyzed, and what seems to be microscopic/incidental version of this process was identified in 10 examples (8%). These microcysts were found lying within compact acinar tissue, and appeared to be transforming from intercalated ducts, some focally connected to acinar elements, and they had abortive (nonbridging) septae with pseudo-loculated appearance, irregular contours and often showed tightly packed clusters of ducts with similar morphology described in the cases underwent resection specifically for this cyst type. In conclusion, the distinctive morphologic, immunophenotypic, and clinical characteristics of this cystic lesion warrant its classification as a separate entity. We propose to refer to it as squamoid cyst of pancreatic ducts. It seems to be a metaplastic cystic transformation beginning in the intercalated ducts. Although obstructive etiology is suspected, a specific factor or surrogate evidence of obstruction such as chronic pancreatitis is typically lacking.

The role of endoscopic ultrasound and endoscopic ultrasound-guided fine-needle aspiration in distinguishing pancreatic cystic lesions

Distinguishing mucinous from nonmucinous cystic lesions of the pancreas often constitutes a diagnostic dilemma. The clinical management differs between such lesions; therefore it is important to make an accurate preoperative diagnosis. Various centers have reported conflicting results regarding their ability to detect mucin-producing neoplastic cells and appropriately reach a diagnosis based on endoscopic ultrasound (EUS) guided FNA. The aim of this study is to assess the ability of EUS-FNA cytology to diagnose and differentiate mucinous from nonmucinous pancreatic cystic lesions. We reviewed records of patients who underwent EUS of pancreatic cystic lesions. If FNA was performed and mucinous neoplasm was suspected, aspirate was evaluated for cytomorphology and presence of mucin. FNA results were compared to final histologic diagnosis if surgery was performed. Cytologic diagnosis was provided for 28/30 (93%). By comparing EUS-FNA diagnoses with final surgical pathology, FNA accurately diagnosed in 10/11 cases with sensitivity and specificity for detection of malignancy of 100 and 89, respectively, while the accuracy for identification of mucinous cystic neoplasms was 100%. Our results indicate that in the appropriate clinical and imaging setting, EUS-FNA cytology with analysis for mucin production by tumor cells is an important test in distinguishing pancreatic cystic lesions and guiding further management.

Utilizing quantitative polymerase chain reaction to evaluate prostate stem cell antigen as a tumor marker in pancreatic cancer

BACKGROUND

Real-time quantitative polymerase chain reaction (qPCR) may prove to be a sensitive technique by which to evaluate potential tumor markers in pancreatic cancer.

METHODS

The prostate stem cell antigen (PSCA) gene was identified as a marker highly expressed in pancreatic adenocarcinoma and not normal pancreas. RNA from pancreatic and nonpancreatic cancer cell lines as well as tissue and blood from pancreatic cancer and control patients was reverse-transcribed and PSCA quantified by qPCR.

RESULTS

Individual operator experience affects the results of qPCR, with significantly different copy numbers at experiment numbers 5, 15, and 40. Five of six pancreatic cell lines had PSCA/actin ratios 10-fold greater than nonpancreatic cancer lines. Mean PSCA expression in pancreatic tumor tissue was significantly higher (P < 0.05, Student's t-test) than in the tissue of benign pancreatic processes. The close correlation of PSCA/actin copy number with number of tumor cells in the blood was demonstrated by regression analysis (r = 0.768, P = 0.0001). PSCA copy number was significantly higher in the blood of patients with metastatic pancreatic cancer than in that of normal patients (P < 0.05, Student's t-test).

CONCLUSIONS

Such trends suggest that PSCA may prove to be a valuable pancreatic cancer tumor marker. More generally, the technique of qPCR is shown to provide a sensitive method of evaluating markers in cancer patients.

A series of 64 cases of pancreatic cystic neoplasia from an institutional study of China

AIM: To recognize cystic neoplasia of the pancreas and thus to identify a panel of curable diseases.

METHODS: Sixty-four cases of cystic neoplasia of the pancreas, including 28 cases of intraductal papillary mucinous neoplasia (IPMN), 12 cases of serous cystic neoplasia (SCN), 11 cases of mucinous cystic neoplasia (MCN), 11 cases of solid pseudo-papillary neoplasia (SPN), and 2 cases of solid tumor with cystic degeneration were examined immunohistochemically for their expression of MUC1, MUC2, MUC4, MUC5AC, and MUC6, as well as other related antigens.

RESULTS: Adenoma type of IPMN and borderline lesions exhibited high expressions of MUC2, and MUC5AC. In contrast, IPMN with invasive carcinoma component showed MUC1 immunoreactivity. SCN was mainly positive for MUC1 and MUC6, while negative for MUC2, MUC4 and MUC5AC. Noninvasive MCN, regardless of its cellular atypia degree, was positive for MUC5AC and negative for MUC1. MUC1 expression was only observed in patients with an invasive component. No mucin expression was found in SPN.

CONCLUSION: Mucin profile may, in conjunction with histologic study, provide important information on tumor types and patient treatment of cystic neoplasia of the pancreas.

Mesothelial cyst of the pancreas

Cystic lesions of the pancreas are increasingly identified because of advances in imaging techniques. The cystic lesions are of different types and are classified as neoplastic, nonneoplastic, and developmental types. Identification of the nature of these cystic lesions is very important because the course and treatment of disparate types of cysts are different. Here, we describe, for the first time, mesothelial cyst involving the pancreas in a 36-year-old man. Distal pancreatectomy showed a 3-cm unilocular cyst containing clear fluid. The cyst was lined by flat to cuboidal epithelium surrounded by fibrous tissue. The lining epithelial cells were positive for vimentin, thrombomodulin, cytokeratin 5/6, and calretinin, thus confirming the mesothelial nature of the cells.

Primary cilia deletion in pancreatic epithelial cells results in cyst formation and pancreatitis

BACKGROUND & AIMS

Defects in cilia formation or function have been implicated in several human genetic diseases, including polycystic kidney disease (PKD), Bardet-Biedl syndrome, and primary ciliary dyskinesia. Pancreatic lesions are found in approximately 10% of PKD patients, suggesting a connection between cilia defects and pancreatic pathologies. Here, we investigate the role of cilia in pancreas formation and function by analyzing mice that lack cilia in pancreatic cells.

METHODS

Using Cre/lox technology, we conditionally inactivated Kif3a, the gene encoding for a subunit of the kinesin-2 complex that is essential for cilia formation, in pancreatic epithelia. Kif3a mice were studied by immunohistochemical and biochemical methods to assess the morphology and differentiation status of pancreatic cells.

RESULTS

Tissue-specific loss of Kif3a in pancreatic cells resulted in severe pancreatic abnormalities including acinar-to-ductal metaplasia, fibrosis, and lipomatosis. Ductal metaplasia appears to be due to expansion of ductal cells rather than transdifferentiation of acinar cells. Cyst formation, aberrant ductal morphology, and extensive fibrosis associated with severe adhesion to adjacent organs were commonly observed in aged Kif3a mutant mice. Deletion of Kif3a using different pancreas-specific Cre strains suggests that these pancreatic phenotypes might be caused by the absence of cilia in ductal cells. Activation of transforming growth factor beta and Mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) pathways may play a role in these phenotypes.

CONCLUSIONS

These results demonstrate that the absence of cilia in pancreatic cells produces pancreatic lesions that resemble those found in patients with chronic pancreatitis or cystic fibrosis.

Immunohistochemical localization of metallothionein in chronic pancreatitis

Metallothionein (MT) is a low-molecular weight intracellular protein, rich in sulfhydryl residues, and able to bind bivalent metals. MT, like Zn, is a component of the diversified elements of antioxidant system. Recent studies have shown that reactive oxygen species play a role in the pathogenesis and development of chronic pancreatitis. The aim of the study was to identify immunohistochemically (LSAB2-HRP; DAKOCytomation) the localization of metallothionein and to determine MT expression in 9 patients with chronic pancreatitis. Our studies confirm that MT is present in exocrine and endocrine cells of patients with chronic pancreatitis and chronic pancreatitis with concomitant diabetes. They also indicate increased expression of MT, particularly in acinar cells of the pancreas. This suggests that MT is greatly involved in homeostasis of the pancreas and synthesis of pancreatic hormones.

Mucin secreting cystic lesions of the pancreas: treatment by enucleation

Ninety per cent of pancreatic cysts are inflammatory pseudocysts. The other 10 per cent are congenital or neoplastic and include congenital true cysts, retention cysts, lymphoepithelial cysts, the mucinous cystadenoma, mucinous cystadenocarcinoma, and serous microcystic cystadenomas and the more recently described intraductal papillary mucin-secreting neoplasms. The advent of computerized tomographic scanning, endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasonography (EUS) has brought many of these lesions to light when they are minimally symptomatic or are incidentally found while investigating unrelated problems. If there is any suspicion of actual or potentially malignant disease, then total excision of the lesion with part of or the entire pancreas is indicated to achieve a likely cure, as survival is better than for the more common ductal adenocarcinomas. There are few reliable preoperative studies to distinguish accurately the etiology and prognosis of this spectrum of cystic lesions, and usually the actual diagnosis is made only at the time of operation or histopathologic examination after the cystic lesion has been biopsied or excised. If a cyst is confirmed to be totally benign, as in the congenital true cyst, lymphoepithelial cyst, or a benign mucinous cyst, they may lend themselves to nonoperative observation or excision without sacrifice of pancreatic parenchyma. However, many mucin-producing cystic lesions may evolve into a dysplastic or invasive malignant lesion requiring more aggressive resective treatment, and it is important not to miss that diagnosis early when cure is still possible. This report presents four benign mucin-secreting cysts treated by local excision. All four were in the head of the pancreas and communicated with the main pancreatic duct and lacked ovarian-type stroma, thus categorizing them as side-branch intraductal papillary mucinous neoplasms. These lesions were able to be easily dissected out of the pancreas with only one patient developing a transient pancreatic fistula. Intraoperative and final histopathology confirmed the benign status, and these patients have remained disease free 3 to 5 years postoperatively. A review of benign tumors reported to have been treated by cyst enucleation in the literature confirms the rationale of this approach in highly selected lesions.

Performance of endosonography-guided fine needle aspiration and biopsy in the diagnosis of pancreatic cystic lesions

OBJECTIVE

Preoperative diagnosis of cystic lesions of the pancreas remains difficult despite improvement in imaging modalities and cystic fluid analysis. The aim of our study was to assess the performance of endoscopic ultrasonography (EUS) and EUS-guided fine needle aspiration (FNA) in the diagnosis of pancreatic cystic lesions.

METHODS

Data from a series of 127 consecutive patients with pancreatic cystic lesions were prospectively studied. EUS and EUS-guided FNA were performed in all patients, and cystic material was used for cytological and histological analysis as well as for biochemical and tumor markers analysis. Performance of EUS diagnosis, biochemical and tumor markers, and FNA diagnosis were compared with the final histological diagnosis obtained at surgery or postmortem examination. Sixty-seven patients underwent surgery and therefore constituted our study group.

RESULTS

EUS provided a tentative diagnosis in 113 cases (89%). Cytohistological FNA provided a diagnosis in 98 cases (77%). When the results of EUS and EUS-guided FNA were compared with the final diagnosis (67 cases), EUS correctly identified 49 cases (73%), whereas FNA correctly identified 65 cases (97%). Sensitivity, specificity, positive predictive value, and negative predictive value of EUS and EUS-guided FNA to indicate whether a lesion needed further surgery were 71% and 97%, 30% and 100%, 49% and 100%, and 40% and 95%, respectively. Carbohydrate antigen 19-9 > 50,000 U/ml had a 15% sensitivity and a 81% specificity to distinguish mucinous cysts from other cystic lesions, whereas it had a 86% sensitivity and a 85% specificity to distinguish cystadenocarcinoma from other cystic lesions.

CONCLUSIONS

EUS-guided FNA is a valuable tool in the preoperative diagnostic assessment of pancreatic cystic lesions.

Mucinous nonneoplastic cyst of the pancreas: a novel nonneoplastic cystic change?

Cystic lesions and neoplasms of the pancreas are uncommon, but they are of special interest because they can usually be cured by resection. During the last decade, the spectrum of these tumors has increased considerably. We present a series of five cystic lesions of the pancreas that differ from all categories described so far. The patients affected by these tumors were three men and two women (mean age, 57 y). Four lesions were unifocal and involved the head of the pancreas; one was multifocal and involved the pancreatic head and tail. Grossly, these tumors presented as unilocular or multilocular thin-walled cysts that contained turbid fluid, or, in two cases, blood, and lacked any communication with the duct system. Microscopically, the cysts were lined by cuboidal to columnar mucin-producing cells, supported by a small band of dense fibrous stroma. Immunocytochemically, the epithelial cells were positive for cytokeratins 7, 8, 18, 19, and 20 (except one), and Ca 19-9 but were negative for trypsin, CEA, synaptophysin, chromogranin A, calretinin, and alpha-inhibin. In four of the five lesions, the epithelial cells expressed MUC5AC, and in one of the five, MUC1. MUC2 and MUC6 were not expressed in any of the lesions. The stromal cells lacked the nuclear progesterone positivity that is typical of mucinous cystic neoplasms. During a mean follow-up period of 2 years, there were no recurrences or cases of malignant transformation after resection. The results suggest that these cystic lesions are distinct from mucinous cystic neoplasms, the most important entity in the differential diagnosis. Because they may represent a nonneoplastic cystic change of the pancreas, we propose the descriptive term mucinous nonneoplastic cyst for these tumors of unknown pathogenesis.

[A clinicopathologic study on eight cases of cystic and solid tumors of pancreas]

OBJECTIVE

To study the clinicopathologic characteristics, differentiation patterns and histogenesis of cystic and solid tumors of the pancreas (CSTP).

METHODS

8 cases of CSTP were studied using histologic (HE and PAS), immunohistochemical (S-P method) and electron microscopic techniques.

RESULTS

All the patients were adolescent and young adult females, 14-33 years in age (mean 25.3 years) without recurrence after tumor resection. The mean diameter of tumors was 9.6 cm, all encapsulated. Histological examination showed presence of solid sheets, pseudopapillary, in all of the cases. Hemorrhage, foam cells, and cholesterol crystals were often found. Immunohistochemically, 8 cases were positive for alpha(1)-AT and lysozyme; 6 cases expressed vimentin, 2 cases expressed actin, and CgA-positive cells found in the tumor cell nests in one case. All of the cases showed PR, and 4 cases showed ER positive immunoreactivity in the majority of tumor cells, but negative for CK AE1, CK AE3, EMA, Synaptophysin, ACTH, gastrin, somatostatin, insulin, and glucogan in all the cases. Electron microscopy of 3 cases showed evidences of polymorphism in differentiation of the tumor cells, including the transitional appearance into ducts, acinus, and endocrine cells. Weibel-Palade body found in tumor cells in one out of 8 cases.

CONCLUSIONS

(1) CSTP is a distinct clinicopathologic entity in young female patients with a benign clinical course. (2) CSTP develops from primitive pancreatic cells, with the potentiality of developing into ducts, acinus, and endocrine cells.

Cyst fluid cytology and chemical features in a case of lymphoepithelial cyst of the pancreas: A rare and difficult preoperative diagnosis

Most pancreatic cysts (90%) are inflammatory pseudocysts. Approximately 10% of pancreatic cysts are neoplasms, including serous cystadenomas, and mucinous tumors, some of which are malignant. Analysis of pancreatic cyst fluid obtained by percutaneous or endoscopic fine-needle aspiration is increasingly being used for the preoperative diagnosis of pancreatic or peripancreatic cysts. However, cyst fluid chemical and cytologic features in less common types of pancreatic cysts have not been reported. Lymphoepithelial cyst of the pancreas is exceedingly rare, and only occasional individual reports have described cyst fluid findings. We report on a case of lymphoepithelial cyst of the pancreas developing in a middle-aged man. Cyst fluid aspirated under radiological guidance showed elevated levels of carcinoembryonic antigen (CEA), CA19-9, CA 125, and amylase, and a viscosity greater than that of serum. A cell block preparation of a fine-needle aspiration showed tissue fragments with a keratinized squamous lining and a lymphocytic infiltrate in the wall, and abundant background keratinous debris. The cytologic and biochemical findings in this case exhibit similarities to the findings reported in other reports, and may represent a recognizable pattern on cyst fluid analysis.

Measurement of pS2 protein in pancreatic cyst fluids. Evidence for a potential role of pS2 protein in the pathogenesis of mucinous cystic tumors

CONCLUSION

Elevated levels of the growth factor pS2 protein in the cyst fluids of mucinous cystic tumors correlate with earlier observations using immunohistochemical techniques showing that pS2 protein is expressed by these tumors. The markedly elevated levels of pS2 protein compared to normal plasma values suggest that this growth factor may be important in the pathogenesis of pancreatic mucinous cystic tumors.

BACKGROUND

Cystic lesions of the pancreas include inflammatory pseudocysts, serous cystadenomas, and mucinous cystic tumors, some of which are malignant. Previous studies using immunohistochemical techniques have shown that virtually all pancreatic mucinous tumors express pS2 protein. pS2 protein is a growth factor that is believed to be important in the normal process of inflammation and repair. We measured pS2 protein and other growth factors in pancreatic cyst fluids to assess their potential pathophysiologic and diagnostic significance.

METHODS

Levels of pS2 protein were measured in 54 pancreatic cyst fluids by radioimmunoassay. The growth factors, epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and insulin-like growth factors I and II (IGF-I, IGF-II) were measured in 22 cyst fluids using commercial immunoassays.

RESULTS

Mucinous cysts exhibited significantly higher levels of cyst fluid pS2 protein than nonmucinous lesions, including pseudocysts and serous cystadenomas (median: 78,303 pg/mL; range: 218-361,176 pg/mL vs median: 886 pg/mL; range: 0-14,206 pg/mL; p = 0.0001). The level of pS2 in mucinous tumors was markedly higher than plasma values (median: 392 pg/mL). Levels of pS2 protein in malignant mucinous lesions tended to be higher than those in benign mucinous cysts, but this difference was not statistically significant (median: 88,817 vs 64,350 pg/mL; p = 0.159). Levels of other growth factors, including EGF, TGF-alpha, IGF-I, and IGF-II, did not discriminate among the different cyst types, and the values were within normal plasma ranges.

Solitary true cyst of the pancreas in two adults: analysis of cyst fluid and review of the literature

Solitary true cyst of the pancreas in adults is extremely rare. We report two adult cases of solitary true cyst of the pancreas. In a 53-yr-old woman there was discovered, incidentally, a unilocular cyst of 7.0 x 6.5 cm in size in the tail of the pancreas that was noted on abdominal US and CT scan. A 16-yr-old boy presented with abdominal pain, and an abdominal US and CT scan revealed a 6.5 cm cystic mass located in the tail of the pancreas. Both patients underwent distal pancreatectomy. Histologically, the cyst was lined with flattened cuboidal and squamous epithelium without morphological alterations. Analysis of the cyst fluid revealed high CA 19-9 (>100,000 U/L) and Span-1 levels (>60,000 U/L) in both cases. Immunohistochemically, the lining epithelial cells of true cyst were positive for CA 19-9 staining. The clinicopathological features of solitary true cyst of the pancreas in adults are briefly reviewed.

Mucin-producing pancreatic tumors: comparison of MR cholangiopancreatography with endoscopic retrograde cholangiopancreatography

PURPOSE

To compare magnetic resonance cholangiopancreatography (MRCP) with endoscopic retrograde cholangiopancreatography (ERCP) in the detection of mucin-producing pancreatic tumors.

MATERIALS AND METHODS

The authors retrospectively reviewed MRCP and ERCP images obtained in 28 patients with mucin-producing pancreatic tumors. Detectability of the pancreatic duct and its branches, intraductal cystic lesions, and intracystic nodules or septa was assessed.

RESULTS

MRCP depicted cystic dilated ductal branches significantly better than did ERCP (P < .001). The difference in the number of nodules or septa detected with MRCP compared with ERCP was not significant. MRCP, however, simultaneously showed not only the main pancreatic duct but also the cystic lesions; this was not always possible with ERCP.

CONCLUSION

MRCP appears to be more effective and less invasive than ERCP to evaluate changes in the size and extent of tumors and to determine if new lesions appear, as well as to follow up mucin-producing pancreatic tumors.

Lymphoepithelial cyst of the pancreas

A rare case of lymphoepithelial cyst of the pancreas is reported. Microscopically the cyst content consisted of keratinous material and the walls were lined by mature squamous epithelium surrounded by dense lymphoid tissue. Immunohistochemistry showed diffuse reactivity for CD20 and CD3 in the lymphoid tissue and uniform positivity for cytokeratins in the squamous epithelium. Although the histogenesis of lymphoepithelial cysts of the pancreas is not understood, awareness of this lesion is helpful in differentiating it from other pancreatic cystic lesions.

Papillary cystic tumors of the pancreas: assessment of malignant potential by analysis of progesterone receptor, flow cytometry, and ras oncogene mutation

BACKGROUND

Although the biologic behavior of papillary cystic tumor (PCT) of the pancreas is more favorable than the adenocarcinoma, a malignant form has been reported. There has been much controversy as to the histologic evidence for malignancy. The purpose of this study is to evaluate whether the ras oncogene mutation is present in the PCT, together with hormone receptor status and DNA flow cytometry that can be used to predict tumor aggressiveness.

MATERIALS AND METHODS

In 6 collected cases of PCT, estrogen receptors (ER) and progesterone receptors (PR) were detected by immunohistochemical techniques, DNA ploidy and S-phase fraction (SPF) were studied by flow cytometry, and H, K, and N-ras oncogene mutation were analyzed by polymerase chain reaction (PCR).

RESULTS

General strong positive immunostaining of PR and negative staining of ER are found in all 6 cases of PCT, including 5 adolescent girls and one 55-year-old women with areas of anaplastic transformation. Flow cytometry analysis revealed diploid DNA in all 6 cases but higher SPF in the anaplastic portion of the old one. None of the 6 cases showed H-, K-, or N-ras oncogene mutation.

CONCLUSIONS

These results suggest PR status and ras oncogene mutation appear to be not useful in predicting aggressive behavior. DNA ploidy and S-phase fraction may provide useful information for prognosis, but their more precise prognostic value of PCT needs a larger number of cases to clarify.

Azotemia and extrarenal manifestations in old female Han:SPRD (cy/+) rats

In humans suffering from polycystic kidney disease (PKD) a gender difference is seen with males exhibiting a faster rate of progression of chronic renal failure than females. The aim of this study was to examine renal function in female rats suffering from autosomal dominant PKD [Han:SPRD (cy/+)] and to look for the occurrence of extrarenal organ manifestations of PKD. In young (2 months) as well as in old female rats (21 months) relative kidney weight was greater in affected than unaffected animals. In contrast, only the old affected female rats developed azotemia (serum urea 95 +/- 124 mg/dl) and severe cystic kidney transformation. Furthermore, old affected female rats exhibited liver cysts (affected 42%; unaffected 3%) and pancreatic cysts (affected 69%; unaffected 15%). Liver cyst epithelia stained positive for cytokeratin 19, a marker for bile duct epithelia. By immunohistochemistry liver cysts exhibited a similar extracellular matrix composition as observed in renal cysts of the same animals (staining positive for laminin, fibronectin and heparan sulfate proteoglycan, but not collagen I). This study proves PKD in the Han:SPRD (cy/+) rat model to be a truly multiorgan disease with a close resemblance of the human disease.

CT of pancreatic neoplasms. Part II: The unusual tumors

The pancreas gives rise to a remarkable variety of neoplasms other than ductal adenocarcinoma. Although no individual type of tumor in this category is prevalent enough to qualify as common, most types are currently encountered with a frequency far greater than that in decades of the recent past. This change is largely the result of the expanded use of contemporary abdominal imaging. The unusual tumors of the pancreas vary greatly in their biologic behavior and, accordingly, in their clinical consequences and therapeutic requirements. Accurate diagnosis, therefore, can be of considerable clinical relevance. Not only is it worthwhile to distinguish one type of unusual pancreatic tumors from another, it is perhaps of even greater consequence to distinguish the unusual tumors from ordinary pancreatic adenocarcinomas. The goals of this discussion are to expand radiologic awareness of these uncommon but interesting pancreatic neoplasms and to increase familiarity with their diagnostically salient features.

Serum tumor markers and cyst fluid analysis are useful for the diagnosis of pancreatic cystic tumors

BACKGROUND

This study was performed to evaluate the utility of serum and cyst fluid analysis for enzymes (amylase and lipase) and tumor markers (carcinoembryonic antigen, CA 19-9, CA 125, and CA 72-4) in the differential diagnosis of cystic pancreatic lesions.

METHODS

Serum and cyst fluid were obtained from 48 patients with pancreatic cysts (21 pseudocysts, 14 mucinous cystic neoplasms, 6 ductal carcinomas, and 7 serous cystadenomas), observed between 1989 and 1994.

RESULTS

Serum CA 19-9 levels were significantly higher in ductal carcinomas (all > 100 U/mL) and mucinous cystic neoplasms (P < 0.05). CA 72-4 cyst fluid levels were significantly higher in mucinous cystic tumors (P < 0.005), with 95% specificity and 80% sensitivity in detecting mucinous or malignant cysts. A combined assay of serum CA 19-9 and cyst fluid CA 72-4 correctly identified 19 of 20 (pre-) malignant lesions (95%), with only 1 false-positive result (3.6%). Cytology showed a sensitivity of 48% and specificity of 100%.

CONCLUSIONS

Any pancreatic cyst with high serum CA 19-9 values, positive cytology, or high CA 72-4 in the fluid should be considered for resection.

Cystic endometriosis of the upper abdominal organs. Report on three cases and review of the literature

A 34-year-old woman with signs and symptoms of an acute abdomen was found to have a hepatic cyst on NMR- and CT-scan. With the tentative diagnosis of a liver hematoma, a right hemihepatectomy was performed. Histologically, an endometrial cyst of the liver was found. A second case of cystic endometriosis in the liver was revealed ultrasonographically in a 62-year-old woman, complaining of rightsided epigastrical pain. A 28-year-old woman was admitted to the hospital because of recurrent epigastric pain. A cystic tumor of the pancreas could be visualized ultrasonographically and was interpreted as a postinflammatory pseudocyst. Histological examination of the distal pancreatectomy specimen revealed cystic endometriosis. The clinicopathological features of hepatic and pancreatic endometriosis are discussed and the literature concerning these extremely rare lesions is reviewed.

Duodenum-preserving resection of the head of the pancreas: the significance as a diagnostic therapy of the lesion in the pancreatic head

A 75-year-old man who was diagnosed as having mucin-producing pancreatic cystic lesion of the main pancreatic duct by duodenoscopic examination was reported. Because of the low malignant potential of such lesions, duodenum-preserving resection of the head of the pancreas was performed, and the intra-operative histological examination showed no malignancy of the resected pancreatic head and no other surgical procedures, such as lymph-adenectomy nor pancreato-duodenectomy were necessary. The significance of this case report lies in that a less invasive operation should be selected at first to diagnose whether the lesion is malignant or not, and also that the selected operation itself must be sufficient to resect an adequate part of the pancreatic tissue involving the cystic lesion, if not malignant. Here, we report the process to select the procedure and the surgical technique.

Preoperative cyst fluid analysis is useful for the differential diagnosis of cystic lesions of the pancreas

BACKGROUND/AIMS

It has been suggested that activity of pancreatic enzymes and concentrations of tumoral markers in cyst fluid may help to distinguish pseudocyst, serous, and mucinous cystadenomas. The aim of this study was to prospectively assess the reliability of preoperative biochemical and tumor marker analysis in cyst fluids obtained by fine-needle aspiration for pathological diagnosis.

METHODS

Cyst fluid was obtained preoperatively by fine-needle aspiration, and biochemical and tumoral marker values were measured. The diagnosis of cystic tumors (7 serous cystadenomas and 12 mucinous tumors) was established by surgical specimen analysis. Thirty-one pancreatic pseudocysts complicating well-documented chronic pancreatitis were also studied.

RESULTS

Carbohydrate antigen 19.9 levels of > 50,000 U/mL had a 75% sensitivity and a 90% specificity for distinguishing mucinous tumors from other cystic lesions. Carcinoembryonic antigen levels of < 5 ng/mL had a 100% sensitivity and an 86% specificity for distinguishing serous cystadenomas from other cystic lesions. Amylase levels of > 5000 U/mL had a 94% sensitivity and a 74% specificity for distinguishing pseudocysts from other cystic lesions.

CONCLUSIONS

High carbohydrate antigen 19.9, low carcinoembryonic antigen, and high amylase levels in cyst fluid are very indicative of mucinous tumors, serous cystadenomas, and pseudocysts, respectively.

Relation of epidermal growth factor receptor and estrogen receptor-independent pS2 protein to the malignant transformation of mucinous cystic neoplasms of the pancreas

OBJECTIVE

To evaluate the role of epidermal growth factor receptor (EGF-R) and pS2 protein in the evolution of malignancy in mucinous cystic tumors of the pancreas.

BACKGROUND

Mucinous cystic tumors of the pancreas include histologically benign but premalignant mucinous cystic neoplasms and mucinous cystadenocarcinoma. The molecular events leading to transformation from a benign to a malignant mucinous tumor are not known. Overexpression of EGF-R and detection of an estrogen-induced protein (pS2) has been demonstrated in ductal adenocarcinomas of the pancreas, but these factors have not been evaluated in mucinous cystic tumors.

DESIGN

Twenty-six mucinous tumors were examined for EGF-R, pS2 protein, and estrogen and progesterone receptors.

RESULTS

Eight (61.2%) of 13 malignant tumors exhibited increased expression of EGF-R, whereas EGF-R was not detected in any of the 13 benign tumors (P = .002). The pS2 protein was detected in nine of 11 malignant and 11 of 11 benign tumors (P = .480). Estrogen and progesterone receptors were not detected in the epithelium of either tumor type. The median survival time of the patients with EGF-R-negative tumors was 29.0 months compared with 14.5 months for those with EGF-R-positive tumors, but this difference did not reach significance owing to the small population size.

CONCLUSIONS

Overexpression of EGF-R in mucinous cystic tumors, as in ductal adenocarcinomas, may be an important feature associated with malignancy and may have prognostic significance. Failure to detect EGF-R in histologically benign epithelium suggests that the upregulation of EGF-R may be important in the evolution of aggressive behavior. The expression of pS2 protein appears to be independent of estrogen and may play a role in the proliferative activity of mucinous tumors. However, pS2 expression is not a feature associated exclusively with malignancy.

Pancreatic cystic islet-cell tumors. Clinical and pathologic features in two cases with cyst fluid analysis

Cystic islet-cell tumors are rare neoplasms that may be confused with more familiar cystic pancreatic lesions, such as pseudocysts, serous cystadenoma, and mucinous tumors. Analysis of aspirated cyst fluid for tumor markers (carcinoembryonic antigen [CEA], CA-125, and CA-15.3), enzymes (amylase and lipase), viscosity, and cytology has been proposed as an aid to preoperative differential diagnosis. These tests will distinguish mucinous from nonmucinous cysts and usually help in determining malignancy. However, cyst fluid parameters from rarer types of pancreatic cystic tumors have not been described. We report the clinical and pathologic features of two cystic islet-cell tumors including cyst fluid parameters in one of the cases. Two cases of cystic islet-cell tumors were identified by clinical history, histopathologic, and immunohistochemical techniques. Cyst fluid was aspirated intraoperatively from one case and analyzed for CEA, CA-125, CA 15.3, insulin, amylase, viscosity, and cytology. Cyst fluid analysis showed low values for CEA, CA-125, and CA-15.3, low viscosity, and variable amylase content. This spectrum of findings is similar to that of serous cystadenomas. Cyst fluid cytologic examination was positive for neuroendocrine-type epithelial cells and insulin levels were elevated, observations indicative of an islet-cell tumor. Analysis of fluid from cystic islet-cell tumors may aid in the preoperative differentiation of these tumors from more common pancreatic cystic lesions. These findings represent the first report of the characteristics of the fluid in these uncommon tumors.

Expression of CA 72-4 (TAG-72) in the fluid contents of pancreatic cysts. A new marker to distinguish malignant pancreatic cystic tumors from benign neoplasms and pseudocysts

OBJECTIVE

The authors evaluated cyst fluid CA 72-4 as a tumor marker in the differential diagnosis of pancreatic cystic lesions.

SUMMARY BACKGROUND DATA

Pancreatic cystic lesions include inflammatory pseudocysts, serious cystadenomas, and mucinous tumors. Mucinous tumors can be further subdivided into mucinous cystadenocarcinomas and premalignant mucinous cystic neoplasms. The clinical and radiologic features of these lesions are unreliable to make a preoperative diagnosis of these diagnostically difficult lesions. Analysis of aspirated cyst fluid was proposed as an aid to making the preoperative differential diagnosis. Currently, a number of parameters have been reported as useful markers in cyst fluid aspirates, including the tumor markers carcinoembryonic antigen and CA 15.3, enzymes (amylase, lipase, and amylase isoenzymes), relative viscosity, and cytologic analysis. However, owing to the rarity of pancreatic cystic tumors, experience with cyst fluid analysis is limited. To define additional markers that might be useful in the differential diagnosis of pancreatic cysts, the authors measured the tumor-associated glycoprotein 72 (TAG-72) in aspirates from 19 pancreatic cystic lesions.

METHODS

Cyst fluid from 19 pancreatic cysts was obtained by needle aspiration. The tumor marker TAG-72 was measured by a commercial (CA 72-4) immunoassay.

RESULTS

Cyst fluid CA 72-4 levels in mucinous cystadenocarcinomas were markedly elevated (mean, 10,027 U/mL; range, 780 to 34,853 U/mL) compared with that in pseudocysts (mean, 3.8 U/mL; range, < 3 to 5.7 U/mL) and serous cystadenomas (mean and range, < 3 U/mL; p < 0.001). The level of CA 72-4 in benign mucinous cystic neoplasms was intermediate (mean, 44.2 U/mL; range, < 3 to 137 U/mL), but it was statistically different from either carcinomas (p = 0.009) or benign cysts (p < 0.001).

Expression of CA 15.3 protein in the cyst contents distinguishes benign from malignant pancreatic mucinous cystic neoplasms

BACKGROUND

Inflammatory pseudocysts, serous cystadenomas, and mucinous cystic tumors comprise most cystic lesions of the pancreas. The mucinous tumors include mucinous cystic neoplasms, which are benign on histologic examination but have the potential for malignant transformation, and mucinous cystadenocarcinomas. Accurate preoperative classification of pancreatic cysts with clinical and radiologic criteria is often impossible, and as a result many cystic tumors are inappropriately treated as pseudocysts. Analysis of percutaneous needle-aspirated cyst fluid for tumor markers, enzymes, viscosity, and cytologic study has been proposed as a useful modality to distinguish mucinous from nonmucinous cystic lesions. However, no reliable cyst fluid parameter distinguishes benign from malignant mucinous tumors.

METHODS

The concentration of the tumor marker CA 15-3 was measured by immunoassay in cyst fluid from six pseudocysts, five serous cystadenomas, three mucinous cystic neoplasms, and six mucinous cystadenocarcinomas.

RESULTS

The concentration of CA 15-3 in the cyst fluid of mucinous cystadenocarcinomas was higher (mean, 178 units/ml; range, 40 to 392) than that of mucinous cystic neoplasms (mean, 4.7 units/ml; range, 0 to 14), serous cystadenomas (mean, 9.2 units/ml; range, 0 to 32), and pseudocysts (mean, 15.3 units/ml; range, 0 to 66). An upper cutoff value of 30 units/ml distinguished mucinous cystic neoplasms from mucinous cystadenocarcinomas with 100% sensitivity and 100% specificity (p = 0.01).

CONCLUSIONS

Production of CA 15-3 appears to coincide with malignant transformation in pancreatic mucinous cystic neoplasms. We conclude that measurement of CA 15-3 levels in the cyst fluid is useful in the differentiation of benign from malignant pancreatic mucinous cysts.