Molecular and Immunohistochemical Analysis of Mucinous Cystic Neoplasm of the Liver.

OBJECTIVES: Mucinous cystic neoplasm of the liver is characterized by neoplastic mucinous and/or biliary epithelium surrounded by ovarian-type stroma. Immunohistochemical studies have shown that the ovarian-type stroma expresses estrogen receptor, suggesting potential hormonal responsiveness. The molecular biology of mucinous cystic neoplasm of the liver remains poorly studied. METHODS: Transcriptome sequencing and immunohistochemistry were performed on a series of mucinous cystic neoplasms. RESULTS: Mucinous cystic neoplasm of the liver exhibited significantly increased RNA expression of ovarian stromal markers WT1, PR, and ER2 and sex cord stromal markers SF-1, inhibin-α, and calretinin compared with nonneoplastic liver. Immunohistochemistry confirmed the RNA-level data. Evidence for sex hormone biosynthesis was identified by significant overexpression of multiple estrogen biosynthetic enzymes. Expression of 17ß-hydroxysteroid dehydrogenase 1 was confirmed immunohistochemically. Pathway analysis also identified significant upregulation of the hedgehog and Wnt pathways and significant downregulation of T-helper 1 and T-helper 2 pathways. CONCLUSIONS: Mucinous cystic neoplasm of the liver recapitulates ovarian stroma at the morphologic, DNA, RNA, and protein levels. These data support the concept that this tumor likely arises from ectopic primitive gonadal tissue and/or stromal cells with capacity to transdifferentiate to ovarian cortical cells.

Two types of primary mucinous ovarian tumors can be distinguished based on their origin.

The origin of primary mucinous ovarian tumors is unknown. We explore the hypothesis that they originate from either Brenner tumors or teratomas and examine differences between the tumors that arise in these settings. A total of 104 Brenner tumor-associated mucinous tumors and 58 teratoma-associated mucinous tumors were analyzed. Immunohistochemistry for 21 antigens and fluorescence in situ hybridization for ERBB2 and MYC were performed. Genome-wide copy number analysis and mutation analysis for 56 cancer-related genes was carried out on a subset of mucinous ovarian tumors and their complementary Brenner tumor or teratoma. Patients with teratoma-associated mucinous tumors were significantly younger than patients with Brenner tumor-associated mucinous tumors (43 vs. 61 years). During progression from cystadenoma to atypical proliferative mucinous (borderline) tumor to carcinoma expression of typical gastrointestinal markers was increased in both Brenner tumor-associated and teratoma-associated mucinous tumors. Brenner tumor-associated mucinous tumors showed more frequently calcifications and Walthard cell nests, rarely expressed SATB2 and showed more often co-deletion of CDKN2A and MTAP. Teratoma-associated mucinous tumors were characterized by mucinous stromal dissection, SATB2 expression and RNF43 mutations. Other frequent mutations in both Brenner tumor-associated and teratoma-associated mucinous tumors were TP53 and KRAS mutations. Based on identical mutations or copy number profiles clonal relationships were indicated in two mucinous tumors and their associated Brenner tumor. Teratomas and Brenner tumors give rise to different subtypes of mucinous ovarian tumors. Subsequent progression pathways are comparable since both Brenner tumor-associated and teratoma-associated mucinous tumors develop a gastrointestinal immunophenotype during progression and show early mutations in KRAS and TP53. Teratoma-associated mucinous tumors may more closely resemble true gastrointestinal tumors, indicated by their expression of SATB2 and the presence of RNF43 mutations.

S100P is a useful marker for differentiation of ovarian mucinous tumors.

The S100P protein stimulates cell proliferation and survival, thereby contributing to tumor progression. The purpose of this study was to evaluate S100P expression in the three subtypes of mucinous cystic tumors, cystadenomas, borderline tumors, and adenocarcinomas. The authors examined nuclear S100P expression in 60 mucinous ovarian tumor specimens, including 24 specimens of mucinous cystadenoma, 15 of borderline tumors, and 21 of adenocarcinomas. Immunohistochemistry revealed S100P expression followed one of three patterns: (1) Expressed in most nuclei of mucinous epithelial cells, (2) sporadic (spotted or patchy) expression, or (3) absent or rarely expressed in the nuclei of mucinous epithelial cells. Most adenomas showed the first expression pattern, and borderline tumors often showed a patchy expression pattern. Adenocarcinomas generally demonstrated absence of S100P expression. These data suggest that S100P is a useful histological marker to differentiate between benign, borderline, and malignant mucinous tumors of the ovary.

Primary retroperitoneal mucinous cystadenoma: A case report.

Primary retroperitoneal mucinous cystic tumors are extremely rare. These tumors can be classified as a primary retroperitoneal mucinous cystadenoma with or without borderline malignancy or primary retroperitoneal mucinous cystadenocarcinoma. The most common of these is primary retroperitoneal mucinous cystadenoma, which almost always occurs in female patients; only ten cases have been reported in males. The most common clinical findings for this tumor type include nonspecific abdominal pain and a palpable abdominal mass. A definitive diagnosis is usually obtained from histopathology after surgical excision. Here, we report the case of a 60-year-old female patient who complained of abdominal pain that had been present for 3 mo and presented with a palpable abdominal mass. Multidetector computed tomography scanning revealed a large, unilocular cystic mass in the left retroperitoneal space. Surgical intervention was performed and the tumor was completely removed. Histopathologic examination confirmed that the tumor was a primary retroperitoneal mucinous cystadenoma. Two years after surgery, the patient remains disease free.

Inhibitory role of prohibitin in human ovarian epithelial cancer.

OBJECTIVES: To characterize the exact individual roles of gonadotropins on ovarian epithelial carcinogenesis, an earlier study showed that prohibitin was significantly up-regulated by luteinizing hormone (LH). To further clarify the role of prohibitin in ovarian carcinogenesis and its association with LH, herein we studied the expression of prohibitin in various ovarian tissues including different developmental stages of ovarian epithelial tumors. METHODS: A total of 135 samples were studied by immunohistochemistry. These included benign ovarian cases with follicles, ovarian surface epithelia and ovarian epithelial inclusions (OEI) (n=30), serous cystadenoma (n=14), serous borderline tumor (n=12), serous carcinoma (n=20), mucinous cystadenoma (n=10), mucinous borderline tumor (n=10), mucinous carcinomas (n=10), endometrioid carcinomas (n=12), poorly/undifferentiated carcinomas (n=5), and fallopian tube (n=12). RESULTS: Strong and diffuse staining of prohibitin was detected in luteinized ovarian stromal cells, follicular cells, fallopian tube, and OEI with serous differentiation. A significantly higher prohibitin expression in luteinized stromal cells than in non-luteinized stromal cells was observed (P<.01). Within the ovarian epithelium, the level of prohibitin expression was basically negative in ovarian surface epithelia, but highly expressed in OEI. However, compared to the level of prohibitin expression in OEI, it showed a trend of gradual loss from benign ovarian tumors, to borderline tumors and to carcinomas (P<.0001). Compared to the serous tumors, epithelial tumors with mucinous differentiation showed a significant lower level of prohibitin (P<.0001). An inverse correlation was noted between prohibitin expression and cancer grade. It is interesting to note that a high prohibitin expression level was seen in the fallopian tube, which is similar to OEI. CONCLUSIONS: These data further suggest that prohibitin plays a tumor suppressing role, which is probably associated with LH mediated protection role against ovarian epithelial carcinoma. In addition to the tumor suppressive role of prohibitin, it also plays a role in cellular differentiation, which may be helpful to differentiate ovarian mucinous tumors from the tumors with serous differentiation in clinical settings. More importantly, our findings are supportive that the ovarian epithelial cancers, particularly the serous cancers including those precursors with serous differentiation are likely to be derived from fallopian tube instead of ovarian surface epithelia.

Primary mucinous cystadenoma of the spermatic cord within the inguinal canal.

We report a hitherto not documented case of primary mucinous cystadenoma arising in the spermatic cord within the right inguinal canal of a78-year-old man. The tumor was painless, hard and mobile. A computed tomography scan on the pelvis revealed an oval shaped, low attenuation mass, measuring 5.0x2.5x2.1 cm, that was present adjacent to the vas deferens. Grossly, the excised mass was multicystic mucinous tumor, filled with thick mucoid materials. Microscopically, the cystic wall was irregularly thickened. The cystic epithelium commonly showed short papillae lined by a single layer of columnar to cuboidal mucinous epithelial cells without significant stratification or cytologic atypia. Goblet cells were also frequently present. Immunohistochemically, the neoplastic cells showed positive reaction to carcinoembryonic antigen, cytokeratin 20, CDX2, epithelial membrane antigen, and CD15. However, they were negative for PAX8 and Wilms' tumor 1 protein. Pathological diagnosis was a papillary mucinous cystadenoma of the spermatic cord. Although mucinous cystadenoma in this area is extremely rare, it is important that these lesions be recognized clinically and pathologically in order to avoid unnecessary radical surgery. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1720965948762004.

Glycosylation variants of mucins and CEACAMs as candidate biomarkers for the diagnosis of pancreatic cystic neoplasms.

BACKGROUND AND AIMS: Cystic lesions of the pancreas are increasingly being recognized due to the widespread use of high resolution abdominal imaging. Since certain cyst types are precursors to invasive cancer, this situation presents an opportunity to intervene prior to malignant progression. Effective implementation of that strategy has been hampered by difficulties in clearly distinguishing cystic lesions with no malignant potential from those with malignant potential. Here we explored whether glycosylation variants on specific proteins in cyst fluid samples could serve as biomarkers to aid in this diagnosis. METHODS: We used a novel antibody-lectin sandwich microarray method to measure the protein expression and glycosylation of mucin (MUC)1, MUC5AC, MUC16, carcinoembryonic antigen, and other proteins implicated in pancreatic neoplasia in cyst fluid samples. Fifty-three cyst fluid samples were obtained from patients with mucinous cystic neoplasms (n=17), intraductal papillary mucinous neoplasms (n=15), serous cystadenomas (n=12), or pseudocysts (n=9), with confirmation of histologic diagnosis at surgical resection. RESULTS: The detection of a glycan variant on MUC5AC using the lectin wheat-germ agglutinin discriminated mucin-producing cystic tumors (mucinous cystic neoplasms+intraductal papillary mucinous neoplasms) from benign cystic lesions (serous cystadenomas+pseudocysts) with a 78% sensitivity at 80% specificity, and when used in combination with cyst fluid CA 19-9 gave a sensitivity of 87% at 86% specificity. These biomarkers performed better than cyst fluid carcinoembryonic antigen (37%/80% sensitivity/specificity). CONCLUSIONS: These results demonstrate the value of glycan variants for biomarker discovery and suggest that these biomarkers could greatly enhance the accuracy of differentiating pancreatic cystic tumors. Validation studies will be required to determine the clinical value of these markers.

Primary retroperitoneal mucinous tumors: a clinicopathologic study of 18 cases.

Primary retroperitoneal mucinous tumors (PRMTs) are uncommon neoplasms occurring almost exclusively in women. PRMTs are divided into mucinous cystadenoma (MC), mucinous borderline tumors or tumors of low malignant potential (MLMP), and mucinous carcinomas (MCas). In this retrospective study, we present the clinicopathologic features of 18 such cases, the largest series to date. All patients were women, ranging in age from 20 to 63 years (mean 38.6 y). All except 2 patients presented with an enlarged mass during a routine examination or by self-palpation. All tumors were located exclusively in the retroperitoneum, with histologic or clinical confirmation of the lack of ovarian involvement. The tumors ranged from 7 to 26 cm (mean 13.2 cm). The gross appearance was variable: unilocular cyst with a thin wall (4 cases), predominantly cystic with papillary areas or nodule(s) (8 cases), multiloculated cyst with or without nodules (1 case each), and predominantly solid with cystic areas (4 cases). Histologically, there were 2 cases of MC, 7 of MLMP (7 cases; 3 of them with intraepithelial carcinoma and 1 with microinvasion), and 9 of MCas (9 cases, 5 of them associated with MLMP and 1 associated with MC). Three of the MCas had areas of anaplastic or sarcomatoid carcinoma whereas 1 had an associated sarcoma. Immunohistochemical studies were performed in 6 cases. Cytokeratin 7 was diffusely positive in all cases studied, whereas cytokeratin 20 and cytokeratin 17 were focally positive in 4 and 2 cases, respectively. All patients underwent surgical resection of the entire tumor. Two patients with MCa and sarcoma or sarcomatoid carcinoma received chemotherapy. Follow-up was available in 16 cases, ranging from 1 to 148 months (mean 40 mo, median 22 mo). Two patients died of disease at 5 and 9 months; both had MCa with anaplastic carcinoma or sarcoma. Three patients with MCa were alive with disease at 14, 26, and 58 months. The remaining patients were alive with no evidence of disease. In this study, MLMP and MCa were more common than MC. PRMTs seem to be nonaggressive neoplasms, except in cases containing anaplastic carcinoma or sarcoma.

Serous and mucinous ovarian tumors express different profiles of MMP-2, -7, -9, MT1-MMP, and TIMP-1 and -2.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play key roles in tumorigenesis, but little is known of their expression according to mucinous or serous type. This study aimed to evaluate the immunohistochemical expression of MMP-2, -7, -9, MT1-MMP, TIMP-1 and -2 in these tumors. A tissue microarray was set up including 99 serous (25 benign, 27 borderline, 47 malignant) and 79 mucinous (25 benign, 44 borderline, 10 malignant) ovarian tumors. Immunostaining results were scored by using the HSCORE and assessed by univariate, unsupervised hierarchical clustering and multidimensional scaling analyses. Epithelial expression of MMP-2, -7, -9, MT1-MMP, TIMP-2, but not TIMP-1, was higher in serous than mucinous tumors. Stromal expression of MMP-7 was higher in serous tumors. Alterations in MT1-MMP, MMP-7 and -9 were found in malignant serous tumors, while benign and borderline tumors shared similar expressions. By unsupervised hierarchical clustering analysis, mucinous and serous tumors were better differentiated by epithelial than stromal MMP and TIMP immunolabelling. By multidimensional scaling analysis, the expressions of MMPs and TIMPs were scattered in serous tumors and homogeneous for mucinous tumors. In conclusion, our results support the differential expression in MMPs and TIMPs of ovarian tumors according to serous or mucinous histology.

The importance of cyst fluid analysis for differentiation of pancreatic cyst.

Cystic abnormalities of the pancreas encompass a wide variety of lesions ranging from the non-malignant pseudo-cyst to neoplastic lesions. Although cystic neoplasms of the pancreas are rare, differentiation is important in determining the proper treatment. A 55-year-old female presented with a cystic abdominal mass. Her computed tomography scan showed a cystic mass of 102 x 99 x 97 mm which was well-circumscribed and homogeneous with few thin septations and mild contrast enhancement of the fibrous wall located in the body of the pancreas. Percutaneous diagnostic aspiration of the cyst fluid was performed under ultrasonic guidance for proper diagnosis and management, which revealed a CEA greater than 200 ng/ml (0-3) and amylase within normal limits 30 U/L (< or = 100). High CEA and normal amylase values supported the diagnosis of mucinous cystadenoma rather than pseudo-cyst. With these findings, the patient underwent distal pancreatectomy with splenectomy. Pathological analysis revealed a mucinous cystadenoma of the pancreas. This report is a confirmation that cyst fluid analysis can provide a pre-operative classification of these diagnostically difficult lesions.

Undifferentiated carcinoma with osteoclast-like giant cells arising in a mucinous cystic neoplasm of the pancreas.

A 26-year-old woman presented with pain in the left hypochondrium, for which pancreatectomy and splenectomy was performed, with total gross excision of a mass. A tumor measuring 11 x 9 cm was found in the pancreas. On cut surface there were two cysts filled with a necrotic substance and hemorrhagic content. Spindle or ovoid-shaped cells, in the sarcomatous component, had diffusely infiltrated along the inner side of the walls of one cyst. Osteoclast-like giant cells (OGC) were also contained in the sarcomatous component. Adenoma components of mucinous epithelium with foci of borderline and adenocarcinomatous components were seen on the inner side of the other cyst. An ovarian-type stroma beneath the epithelial component was seen in the cyst wall. A diagnosis of undifferentiated carcinoma with OGC arising in a mucinous cystic neoplasm (MCN) of the pancreas, was made. Seven months after the initial operation the patient had a local recurrence, and the tumor was removed. One month after the second operation, the patient was free of symptoms. Only four cases of undifferentiated carcinoma with OGC arising in MCN, involving an ovarian-type stroma of the pancreas, have been reported.

Immunohistochemical similarities between pancreatic mucinous cystic tumor and ovarian mucinous cystic tumor.

OBJECTIVE: Pancreatic mucinous cystic tumor (MCT(P)) and ovarian mucinous cystic tumor (MCT(O)) show common features. However, there are few studies showing a comparison of both types of tumor. We immunohistochemically studied both types of tumor to clarify their characteristics. METHODS: Eight patients with MCT(P) and 21 patients with MCT(O) were examined. The tumors were immunohistochemically examined using antibodies against female sex hormone receptors (estrogen receptor, progesterone receptor, and alpha-inhibin), pancreatobiliary tissue markers (carbohydrate antigen 19-9 and DUPAN2) and cell cycle regulators (p27kip1 and phosphorylated retinoblastoma). Samples from 7 female patients with invasive pancreatic ductal carcinoma (DC), 8 female patients with normal pancreatic tissue, and 10 patients with normal ovarian tissue were also examined. RESULTS: In the tumor epithelial cells, the expressions of DUPAN2 and p27/kip1 were similar between MCT(P) (38% and 88%, respectively) and MCT(O) (14% and 76%, respectively), but significantly different between both tumors and DC (100% and 0%). In the stromal cells, the expressions of estrogen receptor, progesterone receptor, alpha-inhibin, and p27/kip1 were similar between MCT(P) (63%, 75%, 50%, and 63%, respectively) and MCT(O) (57%, 71%, 81%, and 57%, respectively), but significantly different between both tumors and DC (0%, 0%, 0%, and 0%, respectively). CONCLUSIONS: MCT(P) and MCT(O) have several immunohistochemical similarities and are significantly different from DC. The female sex hormone system may play a major role in the development of both MCT(P) and MCT(O). A frequent p27/kip1 expression level was associated with nonaggressive progression of both tumors.

A comprehensive study of nondysplastic and dysplastic serrated polyps of the vermiform appendix.

Serrated colorectal polyps often show DNA hypermethylation and/or BRAF mutations and have been implicated in the "serrated neoplastic pathway." Although similar lesions occur in the appendix, they have never been systematically investigated. We evaluated a study group of 56 serrated polyps, a control group of 17 mucinous cystadenomas, and 4 adenocarcinomas with adjacent serrated polyps of the appendix to better understand their pathogenesis. The study cases were classified as nondysplastic or dysplastic serrated polyps and evaluated for MLH-1, MSH-2, MGMT, beta-catenin, p53, and Ki-67 expression, BRAF and KRAS mutations, and microsatellite instability. Serrated polyps usually occurred in older adults with no sex predilection. Most (59%) lacked dysplasia, but all showed similar molecular features, regardless of the degree of dysplasia present. Decreased MLH-1 (50%, P<0.001) and/or MGMT (59%, P<0.001) expression and BRAF (29%, P=0.007) mutations were significantly more common in serrated polyps, but BRAF mutations were detected in a minority of the extracted DNA in 15/16 cases. Of the 28 cases with decreased MLH-1 expression, none showed high-frequency microsatellite instability. Loss of MLH-1 (25%) or MGMT (50%) expression and BRAF or KRAS mutations (50%) were inconsistently present in adenocarcinomas and were not identified in combination in any cases. We conclude that molecular features of the "serrated neoplastic pathway" are present with similar frequencies among dysplastic and nondysplastic serrated appendiceal polyps and are not highly prevalent in adjacent carcinomas. These features, including BRAF mutations, may be more closely related to a serrated morphology in appendiceal polyps rather than biologically important changes.

Prognostic significance of extracellular matrix metalloproteinase inducer and matrix metalloproteinase 2 in epithelial ovarian cancer.

AIMS: We investigated the prognostic significance of extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase 2 (MMP-2) in epithelial ovarian cancer as well as their relation to hyaluronan (HA) expression. METHODS: The expression of EMMPRIN and MMP-2 was analyzed immunohistochemically in 295 primary epithelial ovarian cancer patients and 67 metastases. RESULTS: A low membranous EMMPRIN expression was detected more often in serous tumors than in other types (p < 0.0005) and it was associated with tumors of advanced stage (p = 0.012) or with a large primary residual (p = 0.011). A low expression of MMP-2 in cancer cells was associated with a high histologic grade (grade 3) of the tumor (p = 0.005) and endometrioid type of tumors (p < 0.0005). Stromal MMP-2 expression was significantly associated with strong stromal HA expression (p = 0.002, r = 0.187). In univariate analysis, 10-year disease-related (DRS) and recurrence-free survivals were significantly better when MMP-2 expression in cancer cells was high (p = 0.0057 and p = 0.0467, respectively). DRS was also better when membranous EMMPRIN expression was high (p = 0.013). In multivariate analysis, strong MMP-2 in cancer cells (RR = 1.48, CI = 1.07-2.04, p = 0.017) indicated favorable DRS. CONCLUSION: Our results show that EMMPRIN and MMP-2 in cancer cells are significant indicators of a favorable prognosis of epithelial ovarian cancer.

Diagnostic value of mucins (MUC1, MUC2 and MUC5AC) expression profile in endoscopic ultrasound-guided fine-needle aspiration specimens of the pancreas.

Mucins are aberrantly expressed in various malignancies. We immunohistochemically tested mucins expression (MUC1, MUC2 and MUC5AC) in EUS-FNA samples from pancreatic occupying lesions for the diagnostic utility. The prevalence of MUC1, MUC2 and MUC5AC expression in pancreatic cancers were 77.5% (31/40), 10.0% (4/40) and 80.0% (32/40), respectively, and in the benign pancreatic diseases 25% (4/16), 31.3% (5/16) and 43.8% (7/16). MUC1 and MUC5AC significantly overexpressed in pancreatic cancer, and MUC1 negatively related with tumor differentiation degree (p < 0.05). The prevalence of MUC1, MUC2 and MUC5AC expression in pancreatic mucinous neoplasms were 66.7% (12/18), 38.9% (7/18) and 88.9% (16/18), respectively, and in the pancreatic non-mucinous neoplasms 60.5% (23/38), 5.3% (2/38) and 57.9% (22/38). MUC2 and MUC5AC significantly overexpressed in pancreatic mucinous neoplasms, especially MUC2 in benign mucinous neoplasms (p < 0.05). Compared with cytology alone, the combination test of MUC1+cytology, and MUC5AC+cytology could achieve higher sensitivity (85 vs. 65%, 100 vs. 65%) and accuracy (89.3% vs. 73.2%, 91.1% vs. 73.2%) for pancreatic cancer diagnosis; the combination test of MUC2 + cytology, and MUC5AC + cytology could achieve higher sensitivity (77.8% vs. 38.9%, 100% vs. 38.9%), and specificity (97.4% vs. 60.5%, 71.1% vs. 60.5%) accuracy (100% vs. 51.8%, 80.4% vs. 51.8%) for mucinous neoplasm diagnosis. The panel MUC1+/MUC2-/MUC5AC+/ was higher specific in pancreatic cancer diagnosis, as well as MUC1-/MUC2+/MUC5AC+/ in pancreatic mucinous neoplasms. Our observations suggest the mucins expression profile in EUS-FNA specimens has higher value for the diagnosis of pancreatic cancer and mucinous neoplasms.

Paratesticular mucinous cystadenoma arising from an oviduct-like müllerian remnant: a case report and review of the literature.

A mucinous cystadenoma of the paratestis arising from an unequivocal oviduct-like structure in an 18-year-old man is reported. Mucinous cystadenomas of the testis and paratestis are extremely rare benign tumors of controversial origin. The diagnosis may be challenging and is of clinical importance because these lesions may mimic a teratoma, and teratomas in postpubertal males carry a malignant potential regardless of the degree of maturation. A few case reports and reviews of testicular and paratesticular mucinous neoplasms resembling ovarian tumors have suggested the possibility of a müllerian origin of these tumors. However, no histologic evidence has been found to support such a histogenesis. The current case demonstrates a clear transition from müllerian-type tubal epithelium to intestinal-type mucinous epithelium. This finding, in conjunction with immunophenotypic studies, strongly supports a derivation from a paratesticular müllerian remnant. To our knowledge this represents the first substantial evidence that, in at least some cases, mucinous cystadenomas of the testis and paratestis are of müllerian derivation.

Cyst fluid analysis obtained by EUS-guided FNA in the evaluation of discrete cystic neoplasms of the pancreas: a prospective single-center experience.

BACKGROUND: Accurate assessment of pancreatic cystic neoplasms is imperative before selecting available treatment options, such as surgical resection, drainage, or conservative therapy. Available modalities, CT and magnetic resonance imaging, have been inconsistent in diagnosis. Reports involving EUS and cyst fluid analysis have been encouraging, including studies of EUS features and/or cyst fluid analysis, which may differentiate pancreatic cystic neoplasms. OBJECTIVE: To retrospectively determine cyst fluid characteristics that differentiate cystic neoplasms. DESIGN: Patient evaluation included (1) EUS features (reported elsewhere) and (2) cyst fluid analysis (carcinoembryonic antigen [CEA], carbohydrate antigen 19-9 [CA 19-9], amylase and lipase, viscosity [VIS], mucin stain, and cytology). Exclusion criteria included the following: intraductal papillary mucinous tumor lesions, bloody cyst aspirate, neuroendocrine tumors, and patients without surgical histopathology. SETTING: Pancreatic Biliary Center, St Luke's Medical Center, Milwaukee, Wisconsin. PATIENTS: A total of 102 patients (60 women, 42 men; age, 23-76 years) presented for evaluation of pancreatic cystic neoplasm; 71 underwent surgical resection. RESULTS: Seventy-one of 102 patients who underwent surgery presented the following histopathologic correlates: 23 pseudocysts (PC), 13 serous cystadenoma (SCyA), 21 mucinous cystadenoma (MCyA), and 14 mucinous cystadenocarcinoma (MCyA-CA). Cyst fluid analysis of these patients showed the following: VIS was lower in PC (mean, 1.3) and SCyA (1.27) when compared with MCyA (1.84) and MCyA-CA (1.9). All mucinous neoplasms had VIS >1.6, whereas only 2 mucinous cystic neoplasms (MCN) had VIS = 1.6 (both PC). The CEA level was significantly higher in MCyA (adenoma [878 ng/mL], carcinoma [27,581 ng/mL]) vs PC (189 ng/mL), and SCyA (121 ng/mL). Amylase levels were higher in PC (7210 U/L) compared with cystic neoplasm (SCyA, 679 U/L; MCyA, 1605 U/L; MCyA-CA, 569 U/L). CONCLUSIONS: Differential diagnosis of pancreatic cystic neoplasm is significantly enhanced by cyst fluid analysis. Elevated CEA (> or =480 ng/mL) and VIS (>1.6) accurately predict MCN from SCyA and PC. Malignant from benign MCN can be differentiated by CEA levels > or =6000 ng/mL.