MORPHOPHENOTYPIC CHARACTERISTICS OF OVARIAN SEROUS BORDERLINE TUMORS.

Borderline ovarian tumors (BOTs) represent particular challenge for diagnosis and clinical management as they are characterized with the features of both benign cystadenomas and malignant carcinomas. The aim of our study was to investigate histomorphological and immunohistochemical characteristics of ovarian serous-papillary borderline tumors, compared to serous cystadenomas and low- and high-grade serous carcinomas. Altogether, 80 formalin fixed and paraffin embedded tissue specimens, distributed in four groups, including serous cystadenoma (group I), serous BOTs (group II), Low (group III) and high (group IV) grade serous carcinomas, were investigated by standard immunohistochemistry, using antibodies against CK7 CK20, WT1, Vimentin, CDX2, CEA, ER, cyclin D1, BCL2, E-cadherin, calretinin, СA125, Ki67, P53. Study results showed, that ovarian serous BOTs are characterized with slightly increase proliferative potential compared to benign cystadenomas, whilst apoptotic potential is retained with the difference from malignant serous carcinomas. p53 mutation is not present, as well as the expression of Vimentin. Overall, ovarian serous BOTs are characterized with highly variable immunohistochemical phenotype and the use of multiple immunohistochemical markers are recommended for the differential diagnosis from low grade serous carcinomas and benign cystadenomas.

Bilateral Sertoli cell adenoma in gonads, associated with serous cystadenoma.

Complete androgen insensitivity syndrome is an extremely infrequent disease. The patients exhibit female phenotype because of insensitivity to the androgen receptor and may develop tumors, especially in their undescended gonads. We report a case of bilateral Sertoli cell adenoma in gonads with unilateral serous cystadenoma, in an elderly phenotypic woman with primary amenorrhea. We also provide radiological and pathological studies.

Tubal origin of 'ovarian' low-grade serous carcinoma.

Ovarian low-grade serous carcinomas are thought to evolve in a stepwise fashion from ovarian epithelial inclusions, cystadenomas, and borderline tumors. The current study was designed to gain insight into the origins of low-grade serous carcinomas (tubal versus ovarian) by comparatively evaluating the morphologic (secretory and ciliated cell distribution) and immunophenotypic (using antibodies to PAX8, tubulin, calretinin, and Ki67) attributes of its putative precursor lesions, the normal tubal epithelium, and the overt malignancy. A total of 226 adnexal tissues from 178 patients were studied, including 98 adnexae removed for non-neoplastic indications, 48 serous cystadenomas, 42 serous borderline tumors, and 38 low-grade serous carcinomas. Normal distal tubal epithelium comprised an admixture of PAX8+/tubulin- secretory cells and PAX8-/tubulin+ ciliated cells with a proliferative index of ∼3%. The vast majority of ovarian surface epithelia displayed a mesothelial phenotype (calretinin+/PAX8-/tubulin-) and low proliferative index (0% (12 per 1000)), although 4% of cases also displayed foci with tubal phenotype (calretinin-/PAX8+/tubulin+). In contrast, most (78%) of the ovarian epithelial inclusions displayed a tubal phenotype and had a significantly higher proliferative index (1%) than ovarian surface epithelium, indicating that in most cases, the ovarian surface epithelium and ovarian epithelial inclusions are of different lineages. There was a progressive decrease in the population of ciliated cells, as evidenced by increasing secretory/ciliated cell ratio, from ovarian epithelial inclusions/cystadenomas to borderline tumors to low-grade serous carcinoma, indicating that the latter is a clonal expansion of secretory cells. Overall, the findings make a strong argument that the ovarian epithelial inclusions with a tubal phenotype is likely derived from fallopian tube through an intraovarian endosalpingiosis rather than through Mullerian metaplasia from ovarian surface epithelium. Genetic and molecular studies are needed to further confirm this finding as tubal origination of ovarian serous cancers will have a significant impact on ovarian cancer prevention and management.

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.

Pancreatic cyst fluid protein expression profiling for discriminating between serous cystadenoma and intraductal papillary mucinous neoplasm.

BACKGROUND: Many patients with benign serous cystadenoma (SCA) of the pancreas will undergo resection because of the inability to reliably discriminate between SCA and premalignant mucinous cysts (intraductal papillary mucinous neoplasm [IPMN], mucinous cystic neoplasm [MCN]). METHODS: Cyst fluid from patients with SCA (n = 15), non main-duct and noninvasive IPMN (n = 32), and noninvasive MCN (n = 12) was aspirated at the time of operative resection and analyzed. Commercially available and custom designed multiplex assays (Luminex) were performed using a biomarker panel developed for pancreatic cancer. Differential protein expression (fluorescence intensity, FI) was compared between the 3 groups for each protein (Wilcoxon rank sum test). Unsupervised sample clustering (hierarchical clustering) and supervised sample classification (prediction analysis for microarrays [PAM]) was then performed. RESULTS: Differential protein expression (P < 0.05) was identified between SCA and IPMN (34/51 proteins, 67%) and between SCA and MCN (13/51 proteins, 25%). The majority of proteins were down-regulated in IPMN and MCN compared with SCA. The only proteins significantly overexpressed in the cyst fluid of patients with mucinous cysts were CEA (median FI: IPMN 11.4, MCN 13.0, SCA 5.3; P < 0.001, IPMN vs. SCA) and CA72.4 (median FI: IPMN 10.4, MCN 10.5, SCA 9.9; P = 0.003, IPMN vs. SCA). Unsupervised cluster analysis demonstrated distinct clustering of SCA and IPMN with some cross-over between MCN. Supervised sample classification with 14 proteins had an overall accuracy rate of 92% between SCA and IPMN. CONCLUSIONS: In this study differential cyst fluid protein expression was observed between SCA and IPMN for the majority of proteins assessed and multimarker sample classification accurately discriminated between SCA and IPMN in 92% of patients.

Identification of malignancy factors by analyzing cystic tumors of the pancreas.

AIM: The diversity in the aggressiveness of cystic tumors of the pancreas - ranging from the usually benign serous cystadenoma to lesions of variable degrees of malignancy - was utilized for the identification of molecular factors that are involved in the occurrence of malignancy. METHODS: We analyzed the transcript profiles of different cystic tumor types. The results were confirmed at the protein level by immunohistochemistry. Also, functional studies with siRNA silencing were performed. RESULTS: Expression variations at the RNA and protein level were identified that are closely correlated with the degree of malignancy. Besides, all tumors could be classified effectively by this means. Many of the identified factors had not previously been known to be associated with malignant cystic lesions. siRNA silencing of the gene with the most prominent variation - the anti-apoptotic factor FASTK (Fas-activated serine/threonine kinase) - revealed a regulative effect on several genes known to be relevant to the development of tumors. CONCLUSION: By a molecular analysis of rare types of pancreatic cancer, which are less frequent in terms of disease, variations could be identified that could be critical for the regulation of malignancy and thus relevant to the treatment of also the majority of pancreatic tumors.

Cytohistological diagnosis of pancreatic serous cystadenoma: a multimodal approach.

AIMS: Serous cystadenomata (SCAs) are benign pancreatic cystic neoplasms that present a diagnostic challenge despite many investigational approaches. Notwithstanding the promise of molecular diagnostics, these tests have limited accessibility in day-to-day surgical pathology practices. We aim to corroborate and build on recent evidence which suggests that positive α-inhibin immunohistochemistry (IHC) is a helpful adjunct in the biopsy confirmation of pancreatic SCA. METHODS: We retrospectively reviewed 22 fine-needle aspirates/biopsies from 14 patients (mean age 65 years, 47-83 years) with pancreatic multicystic lesions radiologically suspicious for SCA (location: 6 body, 2 head, 4 tail, 1 neck, 1 uncinate; cyst size: mean 3.7 cm, 2.0-7.6 cm), as well as an additional 10 pancreatic resection specimens with confirmed SCA; α-inhibin IHC was performed on all cell blocks, biopsy slides and representative resection specimen sections. Where available, associated cyst fluid was analysed for correlative vascular endothelial growth factor A (VEGF-A) and carcinoembryonic antigen levels. RESULTS: An α-inhibin IHC sensitivity of 80% was observed in the cases with resection confirmed SCA. Of the fine-needle aspirate/biopsy specimens, 59% (13/22) contained epithelial cells strongly positive for α-inhibin. When selecting for specimens that exhibited distinct strips of epithelium, the α-inhibin strong positivity rate increased to 73% (8/11). VEGF-A values were supportive of false-negative α-inhibin IHC in three cases and true-negative α-inhibin IHC in one case. CONCLUSION: This study postulates a diagnostic algorithm to confirm pancreatic SCA which may help to decrease unnecessary follow-up endoscopy/surgical resection and would decrease the associated morbidity, mortality and financial costs in patients with this otherwise benign condition.

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.

Serous borderline tumor of the paratestis.

Reported herein is a case of serous borderline tumor (SBT, ovarian epithelial type tumor) of the paratestis, involving the tunica vaginalis, in a 64-year-old man. The patient complained of right hydrocele; puncture cytology of the turbid fluid pointed to an adenocarcinoma. Right orchiectomy was performed and multiple micronodules were grossly observed in the paratestis. On microscopy small papillary epithelial lesions were found with psammoma bodies and intraglandular papillary lesions were irregularly recognized in the stroma of the paratestis, similar to SBT of the ovary. The tumor cells had often short microvilli. Mucin production was evident on PAS and colloid iron staining. Both papillary and glandular epithelial cells were positive on immunohistochemistry for Ber-EP4/epithelial antigen, low-molecular-weight cytokeratin (CAM5.2), cytokeratin 7 and estrogen and progesterone hormone receptors, but negative for CEA, cytokeratin 20 and calretinin. The average proliferative index was approximately 10.5% as assessed on Ki-67 (MIB-1) staining. Ultrastructurally, the cells did not demonstrate any well-developed microvilli or secretory granules and immunohistochemical findings supported SBT of Müllerian type (ovarian epithelial type tumor), while excluding a papillary type of malignant mesothelioma. The lesion in the present case was concluded to be a testicular serous tumor of Müllerian type, similar to SBT of the ovary.

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.

Retinoid receptor alpha and Beta expression in serous ovarian tumors.

The expression of retinoid acid receptors alpha (RARalpha) and beta (RARbeta) and estrogen receptor alpha (ERalpha) was assessed by immunohistochemistry and Western blotting in normal ovaries, serous cystadenoma (n = 20), serous borderline (n = 14), and serous ovarian cancer (n = 47) and was correlated in cancer cases with stage, grade, progress-free survival (PFS), and survival. RARalpha was increasingly expressed in benign cystadenomas, borderline, and low-stage and advanced-stage neoplasms (p < 0.001). In stage III, G3 serous carcinoma, increased RARalpha expression was an independent prognostic factor associated with lower chemoresponse to first-line chemotherapy (taxol and carboplatin) and shorter PFS (p < 0.002).RARbeta and ERalpha expression did not correlate with RARalpha tumor characteristics or PFS and survival.

An immunohistochemical comparison between low-grade and high-grade ovarian serous carcinomas: significantly higher expression of p53, MIB1, BCL2, HER-2/neu, and C-KIT in high-grade neoplasms.

Ovarian serous carcinoma (OSC) is the most common ovarian epithelial malignancy. Recently, a dualistic pathway of ovarian serous carcinogenesis has been proposed based on morphologic observations and molecular genetic analysis. In this scheme, low-grade OSC arises in a stepwise fashion from a benign serous cystadenoma through a usual serous borderline tumor through a micropapillary variant of serous borderline tumor. In contrast, the more common high-grade OSC arises de novo from the ovarian surface epithelium or the epithelium of cortical inclusion cysts with an as yet unrecognized precursor lesion. Although the division of OSC into low- and high-grade variants is gaining greater acceptance, and although there is accumulating molecular genetic evidence for this, there is little published information regarding a comparison of protein expression between these two types of OSC. In this study, we have investigated the immunohistochemical expression of a wide range of proteins in cases of low-grade (n = 22) and high-grade (n = 47) OSC. Antibodies used were p53, MIB1, BCL2, WT1, HER-2/neu, C-KIT, osteopontin, and survivin. For all antibodies, except MIB1, cases were scored as 0 (negative or occasional positive cells), 1+ (<10% cells positive), 2+ (10%-25% cells positive), 3+ (26%-50% cells positive), 4+ (51%-75% cells positive) or 5+ (>75% cells positive). For MIB1, the percentage of positive nuclei was calculated. There was a statistically significant higher expression of p53, MIB1, BCL2, HER-2/neu, and C-KIT in high-grade compared with low-grade OSC (P < 0.05). Thirty of 47 (64%) cases of high-grade OSC exhibited 5+ staining with p53 compared with 4 of 22 (18%) low-grade neoplasms. Twelve of 47 (26%) high-grade OSCs exhibited 5+ staining with BCL2 compared with 1 of 22 (5%) low-grade OSCs. The mean MIB1 proliferative index in high-grade OSCs was 55.4% compared with 23.0% in low-grade OSCs. Virtually all cases of both low-grade and high-grade OSCs exhibited diffuse nuclear positivity with WT1 and diffuse cytoplasmic positivity with survivin. Osteopontin expression was variable with no significant difference in expression between low-grade and high-grade OSC. Although expression of both HER-2/neu and C-KIT was significantly higher in high-grade compared with low-grade OSC, only rare cases exhibited strong positivity with these antibodies, which could be of therapeutic value in individual cases, although this would require additional molecular investigations. The significant differences in protein expression between low-grade and high-grade OSC provides further support for a different underlying pathogenesis. In particular, the differences in p53 immunoreactivity are in keeping with the observation that p53 gene mutation is more common in high-grade than low-grade OSC.

HLA-G is a potential tumor marker in malignant ascites.

PURPOSE: Molecular approaches as supplements to cytological examination of malignant ascites may play an important role in the clinical management of cancer patients. HLA-G is a potential tumor-associated marker and that one of its isoforms, HLA-G5, produces a secretory protein. This study is to assess the clinical utility of secreted HLA-G levels in differential diagnosis of malignant ascites. EXPERIMENTAL DESIGN: We used ELISA to assess whether secretory HLA-G (sHLA-G) could serve as a marker of malignant ascites in ovarian and breast carcinomas, which represent the most common malignant tumors causing ascites in women. RESULTS: On the basis of immunohistochemistry, 45 (61%) of 74 ovarian serous carcinomas and 22 (25%) invasive ductal carcinomas of the breast demonstrated HLA-G immunoreactivity ranging from 2 to 100% of the tumor cells. HLA-G staining was not detected in a wide variety of normal tissues, including ovarian surface epithelium and normal breast tissue. Revese transcription-PCR demonstrated the presence of HLA-G5 isoform in all of the tumor samples expressing HLA-G. ELISA was performed to measure the sHLA-G in 42 malignant and 18 benign ascites supernatants. sHLA-G levels were significantly higher in malignant ascites than in benign controls (P < 0.001). We found that the area under the receiver-operating characteristic curve for sHLA-G was 0.95 for malignant versus benign ascites specimens. At 100% specificity, the highest sensitivity to detect malignant ascites was 78% (95% confidence interval, 68-88%) at a cutoff of 13 ng/ml. CONCLUSIONS: Our findings suggest that measurement of sHLA-G is a useful molecular adjunct to cytology in the differential diagnosis of malignant versus benign ascites.

Laparoscopic fenestration of pancreatic serous cystadenoma: Minimally invasive approach for symptomatic benign disease.

Serous cystadenoma (SC) is a benign pancreatic cystic tumor. Surgical resection is recommended for symptomatic forms, but laparoscopic fenestration of large symptomatic macrocystic SC was not yet described in the literature. In this study, 3 female patients underwent laparoscopic fenestration for macrocystic SC (12-14 cm). Diagnosis was established via magnetic resonance imaging and endoscopic ultrasound, with intra-cystic dosage of tumors markers (ACE and CA19-9) in 2 patients. All patients were symptomatic and operated on 15-60 mo after diagnosis. Radiological evaluation showed constant cyst growth. Patients were informed about this new surgical modality that can avoid pancreatic resection. The mean operative time was 103 min (70-150 min) with one conversion. The post-operative course was marked by a grade A pancreatic fistula in one patient and was uneventful in the other two. The hospital stay was 3, 10, and 18 d, respectively. The diagnosis of macrocystic SC was histologically-confirmed in all cases. At the last follow-up (13-26 mo), all patients were symptom-free, and radiological evaluation showed complete disappearance of the cyst. Laparoscopic fenestration, as opposed to resection, should be considered for large symptomatic macrocystic SC, thereby avoiding pancreatic resection morbidity and mortality.

Serous cystic neoplasms of the pancreas: an immunohistochemical analysis revealing alpha-inhibin, neuron-specific enolase, and MUC6 as new markers.

Serous cystic neoplasms (SCNs) of the pancreas include serous microcystic adenoma (SMA), serous oligocystic ill-demarcated adenoma (SOIA), solid serous adenoma (SSA), von Hippel-Lindau-associated cystic neoplasm (VHL-CN), and serous cystadenocarcinoma (SCC). These neoplasms are histologically similar but differ in their localization, gross appearance, gender distribution, and biology. A centroacinar origin is assumed but has not been proven. To clarify whether the various subtypes of SCN may be distinguished from each other by marker profiles that might also provide evidence of their origin, the immunoprofiles of 38 SCNs (21 SMAs, 13 SOIAs, 2 VHL-CNs, 1 SSA, and 1 SCC) were defined by applying antibodies against cytoskeletal, neuroendocrine, hormone receptor, and mucin markers. In addition, we examined the expression of calretinin and alpha-inhibin. The various types of SCN showed a very similar immunoprofile, characterized by positivity for cytokeratins and neuron-specific enolase and negativity for vimentin and synaptophysin. Further markers that were commonly expressed in SCNs were alpha-inhibin (SMAs: 76%, SOIAs: 92%, VHL-CNs: 100%), MUC6 (SMAs: 60%, SOIAs: 85%, VHL-CNs: 100%), and MUC1 (SMAs: 24%, SOIAs: 38%, VHL-CNs: 50%). Western blot analysis in one SMA revealed a distinct band that stained with neuron-specific enolase antiserum. Alpha-inhibin was only expressed in 4 of 11 acinar cell carcinomas and not in five ductal adenocarcinomas, five neuroendocrine tumors, one mixed ductal-endocrine carcinoma, and one acinar cell cystadenoma of the pancreas. These results suggest that, despite their biologic differences, the various types of SCNs are composed of the same (or a very similar) cell type and may therefore have a common direction of differentiation. This notion is further supported by the finding that neuron-specific enolase, alpha-inhibin, and MUC6, which may be regarded as new markers for this pancreatic tumor type, were also expressed in most SCNs. Because a number of SCNs share MUC1 and MUC6 expression with the pancreatic centroacinar cells, the possibility of a histogenetic relationship has to be considered.

Clear cell endocrine pancreatic tumor mimicking renal cell carcinoma: a distinctive neoplasm of von Hippel-Lindau disease.

The dominantly inherited von Hippel-Lindau disease is characterized by clear cell neoplasms in various organs including the kidney and pancreas. Determination of primary versus metastatic lesion in this setting can be a diagnostic dilemma. The authors present five cases of clear cell endocrine pancreatic tumor (EPT) closely mimicking renal cell carcinomas in five patients with a family history or histologic evidence of von Hippel-Lindau disease. In fact, two of these tumors were confused with metastatic renal cell carcinoma by fine-needle aspiration. All five tumors had a component of clear cells arranged in nests, cords, and tubules with central hemorrhage separated by thin-wall vessels resembling renal cell carcinoma. However, these tumors also exhibited cords and festoons and a gyriform pattern suggestive of an endocrine neoplasm, and expressed chromogranin and synaptophysin. Vascular invasion was identified in four tumors, one of which metastasized. The concurrent primary renal cell carcinomas and the multicentric microcystic adenomas found in three patients did not show reactivity for the neuroendocrine markers. Focal clear cell change was noted in only one of 29 endocrine pancreatic tumors arising in patients without von Hippel-Lindau disease. Eleven metastatic renal cell carcinomas in the pancreas did not show immunoreactivity with the endocrine markers. Clear cell EPTs closely mimicking renal cell carcinoma are distinctive neoplasms of von Hippel-Lindau disease. In contrast to clear cell EPT, metastatic renal cell carcinoma does not express neuroendocrine markers and lacks neurosecretory granules by electron microscopy. Von Hippel-Lindau disease should be strongly suspected in patients with renal cell carcinoma, clear cell EPT, and multifocal microcystic serous adenomas.

Local concentration of folate binding protein GP38 in sections of human ovarian carcinoma by in vitro quantitative autoradiography.

UNLABELLED: Folate binding protein (FBP) GP38 is a membrane-associated glycoprotein that mediates the intracellular transport of folates. The enhanced expression of FBP in ovarian carcinomas provided a rational basis for clinical studies with specific monoclonal antibodies and some newly synthesized antifolate drugs. Because the outcome of these clinical studies ultimately depends on the degree of FBP expression, we measured the local concentration of FBP using 125I-MOv18 monoclonal antibody and quantitative autoradiography. METHODS: Tissue sections from 37 specimens of ovarian carcinoma and 13 nonmalignant ovaries were incubated with increasing concentrations of 125I-MOv18 with and without an excess of unlabeled antibody. Tissue-bound radioactivity was measured by quantitative autoradiography. RESULTS: Folate binding protein was found to be overexpressed in 91% of nonmucinous ovarian carcinomas, with local concentrations ranging between 1.14 and 82.84 pmole/g. Adjacent tumor sections simultaneously studied with 125I-MOv18 and a 125I-labeled folic acid derivative showed matching and superimposable regional distributions of bound radioactivity of the two radioligands, indicating that the antigen, specifically recognized by 125I-MOv18 in nonmucinous ovarian carcinomas, is capable of binding folates. Nonmalignant ovaries did not contain measurable amounts of antigen when assayed with 125MOv18 but showed a limited and specific binding of the 125I-folic acid derivative to tissue sections. The autoradiographic findings were confirmed by testing sections from mixtures of antigen-positive and antigen-negative cells, by immunoperoxidase staining with MOv18 on tumor sections and by biochemical identification of FBP in membrane fractions from tissue samples. CONCLUSION: Folate binding protein is overexpressed up to 80-90-fold in nonmucinous ovarian carcinomas compared with nonmalignant ovaries. Quantitation of FBP may provide a useful tool in the design of clinical studies with specific monoclonal antibodies and certain antifolate drugs that enter the cell through FBP.

Overexpression of p21WAF1/CIP1 and MDM2 characterizes serous borderline ovarian tumors.

Ovarian epithelial tumors are classically divided into benign, malignant, and borderline or of low malignant potential. It is controversial whether this last group of tumors should be considered benign or malignant. Expression of cell cycle markers has recently been linked to tumor behavior and response to treatment. It has been shown that one of the pathways through which the p53 gene controls the cell cycle is by transactivating p21WAF1/CIP1, a cyclin-dependent kinase (cdk) inhibitor. By inhibiting cdks, p21WAF1/CIP1 blocks the G-1 to S-phase transition in the cell cycle. p53 can be regulated by MDM2 (murine double minute-2) through direct inactivation or promotion of its cytoplasmic degradation. In an attempt to investigate the cell cycle checkpoint mechanisms of these tumors, we studied the expression of p53, Ki-67, MDM2, and p21WAF1/CIP1 by immunohistochemistry. We analyzed the expression of these proteins in 19 cystadenomas (8 serous and 11 mucinous), 40 borderline tumors (31 serous and 9 mucinous), and 18 serous carcinomas of the ovary. p21WAF1/CIP1 was expressed in 7 of 19 (37%) benign cystadenomas, 32 of 40 (80%) borderline tumors (93.5% of serous and 33% of mucinous), and in 9 of 18 (50%) serous carcinomas. Ki-67 was only weakly expressed in 8 of 19 (42%) benign cystadenomas, all borderline tumors showed Ki-67 staining in less than 50% of the cells, and 55% of serous carcinomas stained in more than 50% of tumor cells. p53 was absent in all but 1 of the cystadenomas, was expressed in 9 of 40 (22.5%) borderline tumors (25.8% of serous and 11% of mucinous), and in 10 of 18 (55%) carcinomas. All 11 implants of serous borderline tumors expressed p21WAF1/CIP1. Most serous borderline tumors expressed higher levels of MDM2 compared with the benign cystadenomas and carcinomas. Four of the serous borderline implants (40%) expressed MDM2. Coexpression of p21WAF1/CIP1 and MDM2 characterizes serous borderline tumors of the ovary and their implants, which suggests that these cell cycle control proteins are important in these tumors and may be related to tumor progression. Low expression of p53 protein in serous borderline tumors might be in part mediated by MDM2. This suggests that the p53 pathway is intact in most of these tumors, in contrast with carcinomas, in which high expression of p53 has been related to mutations of this gene.

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.