Gene expression profiling supports the hypothesis that human ovarian surface epithelia are multipotent and capable of serving as ovarian cancer initiating cells.

BACKGROUND: Accumulating evidence suggests that somatic stem cells undergo mutagenic transformation into cancer initiating cells. The serous subtype of ovarian adenocarcinoma in humans has been hypothesized to arise from at least two possible classes of progenitor cells: the ovarian surface epithelia (OSE) and/or an as yet undefined class of progenitor cells residing in the distal end of the fallopian tube. METHODS: Comparative gene expression profiling analyses were carried out on OSE removed from the surface of normal human ovaries and ovarian cancer epithelial cells (CEPI) isolated by laser capture micro-dissection (LCM) from human serous papillary ovarian adenocarcinomas. The results of the gene expression analyses were randomly confirmed in paraffin embedded tissues from ovarian adenocarcinoma of serous subtype and non-neoplastic ovarian tissues using immunohistochemistry. Differentially expressed genes were analyzed using gene ontology, molecular pathway, and gene set enrichment analysis algorithms. RESULTS: Consistent with multipotent capacity, genes in pathways previously associated with adult stem cell maintenance are highly expressed in ovarian surface epithelia and are not expressed or expressed at very low levels in serous ovarian adenocarcinoma. Among the over 2000 genes that are significantly differentially expressed, a number of pathways and novel pathway interactions are identified that may contribute to ovarian adenocarcinoma development. CONCLUSIONS: Our results are consistent with the hypothesis that human ovarian surface epithelia are multipotent and capable of serving as the origin of ovarian adenocarcinoma. While our findings do not rule out the possibility that ovarian cancers may also arise from other sources, they are inconsistent with claims that ovarian surface epithelia cannot serve as the origin of ovarian cancer initiating cells.

Defining the cut point between low-grade and high-grade ovarian serous carcinomas: a clinicopathologic and molecular genetic analysis.

A 2-tier grading system based on nuclear grade divides ovarian serous carcinomas into low (nuclear grade 1) and high grade (nuclear grade 3). In most instances the separation is straightforward but at times, the morphologic distinction between them can be difficult. We studied 11 ovarian serous carcinomas with features that were "intermediate" (nuclear grade 2) between low and high grade. All the cases were high staged and had a poor clinical outcome. None of the tumors showed mutations in KRAS, BRAF, and ERBB2 genes that characterize most low-grade serous carcinomas. In contrast, 10 (90.9%) of 11 cases contained nonsynonymous TP53 mutations characteristic of high-grade serous carcinomas. In summary, the molecular genetic profile and behavior of serous carcinomas with grade 2 nuclei are virtually the same as those of serous carcinomas with grade 3 nuclei, supporting the use of the 2-tier grading system for classifying ovarian serous carcinomas.

Melanoma with cartilaginous differentiation: Diagnostic challenge on fine-needle aspiration with emphasis on differential diagnosis.

Fine-needle aspiration (FNA) is a minimally invasive, fast, and accurate diagnostic method for the evaluation of patients with locally recurrent or distant metastases of malignant melanoma. In the vast majority of cases, the diagnosis is straightforward with the characteristic cytologic features well documented in the literature. Divergent differentiation (chondroid, neural, myofibroblastic, and osteocartilagenous) in a melanoma is rare and can potentially create diagnostic challenges if the evaluator is unaware of the same. We report a case of a 46-year-old female with a history of primary anal melanoma who presented with a groin mass. The FNA of the groin mass showed a neoplasm rich in chondroid matrix and raised the possibility of a second primary mesenchymal neoplasm rather than metastasis from the patient's known primary anal melanoma. A review of the histologic features of the anal melanoma showed divergent chondroid differentiation in the anal melanoma with the metastatic deposit in the groin exhibiting extensive chondroid differentiation. The differential diagnostic considerations are discussed.

Aurora kinase inhibitors synergize with paclitaxel to induce apoptosis in ovarian cancer cells.

BACKGROUND: A large percentage of patients with recurrent ovarian cancer develop resistance to the taxane class of chemotherapeutics. While mechanisms of resistance are being discovered, novel treatment options and a better understanding of disease resistance are sorely needed. The mitotic kinase Aurora-A directly regulates cellular processes targeted by the taxanes and is overexpressed in several malignancies, including ovarian cancer. Recent data has shown that overexpression of Aurora-A can confer resistance to the taxane paclitaxel. METHODS: We used expression profiling of ovarian tumor samples to determine the most significantly overexpressed genes. In this study we sought to determine if chemical inhibition of the Aurora kinase family using VE-465 could synergize with paclitaxel to induce apoptosis in paclitaxel-resistant and sensitive ovarian cancer cells. RESULTS: Aurora-A kinase and TPX2, an activator of Aurora-A, are two of the most significantly overexpressed genes in ovarian carcinomas. We show that inhibition of the Aurora kinases prevents phosphorylation of a mitotic marker and demonstrate a dose-dependent increase of apoptosis in treated ovarian cancer cells. We demonstrate at low doses that are specific to Aurora-A, VE-465 synergizes with paclitaxel to induce 4.5-fold greater apoptosis than paclitaxel alone in 1A9 cells. Higher doses are needed to induce apoptosis in paclitaxel-resistant PTX10 cells. CONCLUSION: Our results show that VE-465 is a potent killer of taxane resistant ovarian cancer cells and can synergize with paclitaxel at low doses. These data suggest patients whose tumors exhibit high Aurora-A expression may benefit from a combination therapy of taxanes and Aurora-A inhibition.

Intravascular lymphoma: an unusual diagnostic outcome of an incidentally detected adrenal mass.

OBJECTIVE: To describe a rare diagnosis of intravascular lymphoma in a patient presenting with an incidentally discovered adrenal mass. METHODS: We describe the patient's clinical history and the findings from biochemical evaluation, radiologic studies, and surgical pathology and review the relevant literature. RESULTS: A 43-year-old woman developed sudden onset of flank pain associated with a flushing sensation and presented to the emergency department where computed tomography showed a 5-cm left adrenal mass. She had normal electrolytes, and serum and urinary test results were negative for pheochromocytoma. A 24-hour urinary cortisol level was minimally elevated, and the midnight salivary cortisol value was within the reference range. Magnetic resonance imaging revealed a 6.5 x 5.8-cm left adrenal lesion that demonstrated moderate T2-weighted signal and gradual delayed enhancement with no drop in signal on out-of-phase images. Since the lesion lacked high intensity and the biochemical testing results did not suggest a pheochromocytoma, it was deemed likely that the mass was a malignant lesion of the left adrenal gland. A laparoscopic left adrenalectomy was performed. Morphologic and immunohistochemical findings were consistent with a large B-cell lymphoma, which by virtue of its near exclusive distribution in vascular spaces, was consistent with the diagnosis of intravascular large B-cell lymphoma. CONCLUSION: Intravascular large B-cell lymphoma should be included in the differential diagnosis of an incidentally detected adrenal mass even though the diagnosis is rare.

Utilization of ancillary studies in thyroid fine needle aspirates: a synopsis of the National Cancer Institute Thyroid Fine Needle Aspiration State of the Science Conference.

The National Cancer Institute (NCI) sponsored the NCI Thyroid Fine Needle Aspiration (FNA) State of the Science Conference on October 22-23, 2007 in Bethesda, MD. The 2-day meeting was accompanied by a permanent informational website and several on-line discussion periods between May 1 and December 15, 2007 (http://thyroidfna.cancer.gov). This document summarizes matters regarding the utilization of ancillary studies in thyroid FNA (http://thyroidfna.cancer.gov/pages/info/agenda/).

Vascular "pseudo invasion" in laparoscopic hysterectomy specimens: a diagnostic pitfall.

Total laparoscopic hysterectomy has been shown to be an equally effective and safe technique when compared with conventional abdominal surgery for endometrial carcinoma. The procedure, as performed at our institution, involves the use of a uterine balloon manipulator (RUMI manipulator and Koh Colpotomizer system) for optimal surgical control. The fallopian tubes are cauterized to prevent transtubal spread of the tumor. The balloon manipulator thus creates a positive closed pressure system within the uterine cavity. After observing extensive displacement of tumor into small and large blood vessels in 1 case of grade 1, stage 1b endometrial carcinoma, we reviewed slides from 37 hysterectomy specimens (7 for endometrial carcinoma or atypical hyperplasia and 30 for benign conditions) performed laparoscopically between August 2004 and March 2006 at Emory University and Crawford Long Hospitals. We reviewed all slides for the presence or absence of endometrial tumor/tissue in vascular spaces. Patients with endometrial carcinoma/atypical complex hyperplasia included 6 FIGO grade I endometrioid carcinomas (3 stages 1A; 3 stages 1B) and 1 patient with atypical complex hyperplasia. Tumor within blood vessels was noted in 5 of 7 (71%) cases. In 3 cases, including the case of atypical complex hyperplasia, the number of vessels containing tumor were too numerous to count small and large caliber blood vessels. In the remainder, 1 case had 2 small vessels involved and in the other 7 small vessels showed tumor within vascular lumina. Benign endometrial glands and stromal tissue were noted within vascular spaces in 4 of 30 (13%) hysterectomy specimens removed for benign conditions. We describe a hitherto unreported artifact of vascular pseudo invasion in hysterectomy specimens obtained using the technique of total laparoscopic abdominal hysterectomy. We postulate that the creation of a closed pressure system generated as part of the operative technique is likely responsible for this phenomenon. Pathologists need to be aware of this artifact to avoid misinterpretation of vascular invasion in these cases with its associated therapeutic and prognostic implications.

The development of high-grade serous carcinoma from atypical proliferative (borderline) serous tumors and low-grade micropapillary serous carcinoma: a morphologic and molecular genetic analysis.

Recently, we have proposed a model for the development of ovarian surface epithelial tumors. In this model, all histologic types of surface epithelial tumors are divided into 2 categories designated type I and type II which correspond to 2 pathways of tumorigenesis. Type I tumors include low-grade serous carcinoma, mucinous carcinoma, endometrioid carcinoma, malignant Brenner tumor, and clear cell carcinoma which develop slowly in a stepwise fashion from well-recognized precursors, namely atypical proliferative (borderline) tumors. Type II tumors are high-grade, rapidly growing tumors that typically have spread beyond the ovaries at presentation. They include high-grade serous carcinoma ("moderately" and "poorly" differentiated), malignant mixed mesodermal tumors (carcinosarcomas), and undifferentiated carcinoma. These tumors are rarely associated with morphologically recognizable precursor lesions and it has been proposed that they develop "de novo" from ovarian inclusion cysts. This model implies that the pathogenesis of type I and type II tumors are separate and independent but it is not clear whether some type II tumors develop from type I tumors. In this study, we attempted to address this issue by determining the clonality of 6 cases of high-grade serous carcinomas that were closely associated with atypical proliferative serous (borderline) tumors and invasive low-grade micropapillary serous carcinomas. We reviewed 210 ovarian serous tumors from the surgical pathology files of the Johns Hopkins Hospital and identified 3 high-grade serous carcinoma that were directly associated with atypical proliferative serous (borderline) tumors and 3 that were associated with invasive low-grade micropapillary serous carcinomas. A morphologic continuum between the high-grade carcinoma and the low-grade tumors was observed in 4 cases whereas in the remaining 2 cases the high-grade and low-grade components were separate. Mutational analyses for KRAS, BRAF, and p53 genes were performed on microdissected samples from the high-grade and low-grade tumor areas for each case. All 6 tumors demonstrated wild-type BRAF and p53 genes. Only 2 of the 6 cases were informative from a molecular genetic standpoint. In those 2 cases we found the same mutations of KRAS in both the atypical proliferative serous (borderline) tumor and the high-grade serous carcinoma component of the tumor, indicating a clonal relationship. The above results suggest that the majority of high-grade and low-grade carcinomas develop independently but in rare cases, a high-grade serous carcinoma may arise from an atypical proliferative serous (borderline) tumor.

Cytologic diagnosis of atypical squamous cells of undetermined significance in perimenopausal and postmenopausal women: lessons learned from human Papillomavirus DNA testing.

BACKGROUND: The authors have noted that in cervical cytology specimens from perimenopausal and postmenopausal women, the diagnosis of atypical squamous cells of undetermined significance (ASC-US), as defined in the Bethesda system, is often not associated with a clinically evident lesion on follow-up. Reflex human papillomavirus (HPV) testing provides an opportunity to distinguish cytologic features of significance from those within the spectrum of benign cellular change in this age group. METHODS: Liquid-based preparations that were diagnosed as ASC-US between January 2003 and July 2005 at Emory University Hospital were identified from the computer files. The results of HPV-DNA testing were recorded. Two hundred four Papanicolaou tests from perimenopausal women (n = 81, 40-49 years) and postmenopausal women (n = 123, >50 years) were reviewed in a blinded fashion. RESULTS: HPV-DNA results were available for 903 of 1044 patients diagnosed as ASC-US. Overall, 323 results (35.8%) were positive, 510 results (56.6%) were negative, and 70 results (7.8%) were indeterminate. In addition, 73% of ASC-US specimens in patients aged > or =40 years were negative for HPV DNA. The HPV-DNA detection rate dropped from 60% in the group ages 10 to 19 years to approximately 18% in the group aged >50 years. A review of HPV-negative cases in the group aged >40 years showed squamous cells with random nuclear enlargement and slight hyperchromasia that likely were interpreted as ASC-US (based on the cells that were dotted by the original reviewer). Nuclear grooves were frequent in these nuclei; and cytoplasmic halos, when present, usually were perinuclear. CONCLUSIONS: HPV-DNA detection in cervical cytology specimens has an inverse relation to patient age. A diagnosis of ASC-US in perimenopausal and postmenopausal women is likely to result in a negative HPV-DNA test in a significant proportion of patients. Enlarged nuclei with nuclear grooves and slight hyperchromasia are possibly the cause of ASC-US overdiagnosis in this age group.

Evidence that p53-mediated cell-cycle-arrest inhibits chemotherapeutic treatment of ovarian carcinomas.

Gene expression profiles of malignant tumors surgically removed from ovarian cancer patients pre-treated with chemotherapy (neo-adjuvant) prior to surgery group into two distinct clusters. One group clusters with carcinomas from patients not pre-treated with chemotherapy prior to surgery (C-L), while the other clusters with non-malignant adenomas (A-L). We show here that although the C-L cluster is preferentially associated with p53 loss-of-function (LOF) mutations, the C-L cluster cancer patients display a more favorable clinical response to chemotherapy as evidenced by enhanced long-term survivorships. Our results support a model whereby p53 mediated cell-cycle-arrest/DNA repair serves as a barrier to optimal chemotherapeutic treatment of ovarian and perhaps other carcinomas and suggest that inhibition of p53 during chemotherapy may enhance clinical outcome.

Well-differentiated fetal adenocarcinoma of the lung: cytomorphologic features on fine-needle aspiration with emphasis on use of beta-catenin as a useful diagnostic marker.

Well-differentiated fetal adenocarcinoma (WDFA), also known as low grade adenocarcinoma of the fetal lung type, is a rare pulmonary neoplasm now considered to be a variant of lung adenocarcinoma rather than a type of pulmonary blastoma. Upregulation of the Wnt signaling pathway with subsequent aberrant nuclear/cytoplasmic beta-catenin expression has been recently described in these tumors providing a possible pathogenetic role for this gene in WDFA. We describe the cytomorphologic findings of a case of WDFA in a 36-yr-old female patient and emphasize the diagnostic utility of aberrant nuclear/cytoplasmic expression of beta-catenin as an adjunct to the correct preoperative recognition of this tumor on aspiration cytology.

Emerging roles for PAX8 in ovarian cancer and endosalpingeal development.

OBJECTIVES: Epithelial ovarian carcinomas develop from ovarian surface epithelia that undergo complex differentiation to form distinguishable phenotypes resembling those of the epithelia of the female urogenital regions. While previous studies have implicated regulatory developmental homeobox (HOX) genes in this process, other factors responsible for this differentiation are largely unknown. Aberrant transcriptional expression of PAX8 has been reported in epithelial ovarian cancer, prompting us to initiate the molecular characterization of this master regulatory gene in ovarian cancer development. METHODS: Immunohistochemistry, immunoblotting and RT-PCR were used to investigate the presence of PAX8 and its protein products in epithelial ovarian cancer subtypes, normal ovarian surface epithelia, ovarian inclusion cysts and normal endosalpingeal epithelia. RESULTS: In this report, we confirm microarray results indicating that the transcription factor, PAX8, is highly expressed in epithelial ovarian cancer but absent from the precursor ovarian surface epithelia of healthy individuals. Furthermore, we report that PAX8 is localized to the nucleus of non-ciliated epithelia in simple ovarian epithelial inclusion cysts and in three epithelial ovarian cancer subtypes (serous, endometrioid and clear cell). We also determined that PAX8 is expressed in the non-ciliated, secretory cells of healthy fallopian tube mucosal linings but not in the adjacent ciliated epithelia. CONCLUSION: These findings support the hypothesis that PAX8 plays parallel roles in the development of epithelial ovarian cancer and in the developmental differentiation of coelomic epithelia into endosalpingeal epithelia.

Oxidative stress induces ADAM9 protein expression in human prostate cancer cells.

The ADAM (a disintegrin and metalloprotease) family is a group of transmembrane proteins containing cell adhesive and proteolytic functional domains. Microarray analysis detected elevated ADAM9 during the transition of human LNCaP prostate cancer cells from an androgen-dependent to an androgen-independent and metastatic state. Using a prostate tissue array (N = 200), the levels of ADAM9 protein expression were also elevated in malignant as compared with benign prostate tissues. ADAM9 protein expression was found in 43% of benign glands with light staining and 87% of malignant glands with increasing intensity of staining. We found that ADAM9 mRNA and protein expressions were elevated on exposure of human prostate cancer cells to stress conditions such as cell crowding, hypoxia, and hydrogen peroxide. We uncovered an ADAM9-like protein, which is predominantly induced together with the ADAM9 protein by a brief exposure of prostate cancer cells to hydrogen peroxide. Induction of ADAM9 protein in LNCaP or C4-2 cells can be completely abrogated by the administration of an antioxidant, ebselen, or genetic transfer of a hydrogen peroxide degradative enzyme, catalase, suggesting that reactive oxygen species (ROS) are a common mediator. The induction of ADAM9 by stress can be inhibited by both actinomycin D and cycloheximide through increased gene transcription and protein synthesis. In conclusion, intracellular ROS and/or hydrogen peroxide, generated by cell stress, regulate ADAM9 expression. ADAM9 could be responsible for supporting prostate cancer cell survival and progression. By decreasing ADAM9 expression, we observed apoptotic cell death in prostate cancer cells.

Immunohistochemical detection of p16INK4a in dysplastic lesions of the oral cavity.

Significant intra- and interobserver variability exists in diagnosing and grading oral epithelial dysplasia. Mutations in the tumor-suppressor gene p16 are common in oral cavity dysplastic lesions, but whether immunohistochemical detection of the gene product p16(INK4a) (p16) can be used as a reliable biomarker for dysplasia is unclear. In total, 119 biopsy specimens representing various oral cavity sites and degrees of dysplasia were retrieved from the pathology files of Emory University Hospital. Formalin-fixed, paraffin-embedded sections were stained with hematoxylin and eosin (H&E) and with a monoclonal antibody to p16 (LabVision Corporation, Clone JC2). A blinded review of the H&E slides and the pattern and degree of p16 expression was independently performed by two pathologists. A consensus was obtained when diagnoses differed. Morphologic diagnoses were then compared to p16 immunohistochemical expression. Overall, 61/119 (51%) cases showed no p16 immunoreactivity, including 12/33 (36%) cases of no dysplasia, 11/28 (39%) cases of mild dysplasia, and 38/58 (66%) cases of moderate/severe dysplasia. The remaining cases showed p16 expression limited to the basal and suprabasal nuclei and generally confined to the lower one-third of the epithelium. A logistic regression model showed a trend toward absent p16 expression with increasing severity of dysplasia (P=0.006). Decreased expression of p16 in dysplastic lesions, as found in this study, may reflect the biologic events involving loss of p16 gene function in the pathogenesis of oral cancer. Our findings suggest that p16 immunohistochemistry is not helpful in differentiating dysplastic from nondysplastic mucosa in oral cavity biopsies, and thus is not a reliable biomarker for use in routine clinical practice.

Evaluation of the CD34 and CD10 immunostains using a two-color staining protocol in liver fine-needle aspiration biopsies.

Fine-needle aspiration (FNA) biopsies of liver masses may need immunohistochemistry to resolve difficult cases. We examined liver FNAs with CD10 and CD34 using a two-color staining protocol. Fifty-one cases of hepatocellular carcinoma (HCC) and 23 cases of liver metastases were stained first with CD10 using diaminobenzidine as a chromogen and then with CD34 using Fast Red. All cases were reviewed in a blinded fashion by two of the authors (R.I.Z. and Z.B.). Diagnoses were unblinded and staining patterns evaluated. Forty-eight of 51 cases of HCC stained for CD34 in a peripheral pattern and no cases of metastases stained for CD34 Seven of 23 cases of metastatic disease stained for CD10 in a diffuse cytoplasmic distribution and 29 of 51 HCCs stained in a canalicular pattern. Overall, the sensitivity of the CD10/CD34 combination was 98% and the specificity was 100% for HCC when appropriate staining patterns were observed. Two-color immunostaining with CD10 and CD34 may prove useful in distinguishing HCC from metastases.

Use of novel immunohistochemical markers expressed in colonic adenocarcinoma to distinguish primary ovarian tumors from metastatic colorectal carcinoma.

Distinguishing primary ovarian carcinoma, particularly endometrioid and mucinous subtypes, from metastatic colorectal carcinoma to the ovary is often difficult on histologic examination alone. Recently, three immunohistochemical markers CDX2, a homeobox gene encoding an intestine-specific transcription factor; alpha-methylacyl-CoA racemase (AMACR/P504S), a mitochondrial and peroxisomal enzyme with fairly restricted expression in selective tumors and beta-catenin, an adenomatous polyposis coli (APC) mutation product resulting in activation of the Wnt pathway, have been reported to have specific and sensitive expression in colorectal carcinomas. We evaluated a panel consisting of antibodies to CDX2, beta-catenin and P504S in 23 primary ovarian adenocarcinomas (13 mucinous and 10 endometrioid) and compared the findings to 22 metastatic colorectal adenocarcinomas (seven mucinous and 15 nonmucinous tumors with endometrioid-like morphology hereafter referred to as pseudo-endometrioid) to the ovary stained with the same panel. Twenty (91%) metastatic tumors expressed at least two markers and seven (32%) expressed all three. In contrast, only three (13%) primary ovarian tumors expressed at least two markers and none expressed all three. Strong (2+, 3+) and diffuse (>40%) expression for CDX2 was noted in 21 (95%) metastatic tumors and five (22%) primary ovarian tumors (three mucinous, two endometrioid). P504S was similarly expressed in seven (32%) metastatic and none of the primary ovarian carcinomas. Nuclear expression of beta-catenin was noted in 13 (59%) metastatic tumors and in eight cases (36%), it was diffuse and strong. In contrast, four (19%) primary tumors showed nuclear expression of this protein with only one (5%) case expressing it in a diffuse pattern. Immunohistochemical expression of gene products and enzymes of colorectal carcinogenesis in some primary ovarian carcinomas suggest that the morphologic similarities between colorectal and mucinous/endometrioid carcinoma of the ovary extends to the genetic level, although differences in the level of expression exist between these tumors. Diffuse expression of all three markers (CDX2, beta-catenin and P504S) in a tumor in the ovary was found to be virtually diagnostic of metastasis from a colorectal primary in this study.

Molecular characterization of uterine clear cell carcinoma.

Clinicopathological studies support a broad classification of endometrial carcinoma into two major types, designated as type I and type II, which correlate with their biological behavior. More recently, molecular studies have provided further insights into this classification scheme by elucidating the genetic events involved in the development and progression of endometrial carcinoma. Microsatellite instability and mutations in the PTEN gene have been widely associated with type I (endometrioid) endometrial carcinoma, while p53 mutations have been identified in the majority of type II endometrial carcinoma, of which uterine serous carcinoma is the prototype. Uterine clear cell carcinoma (UCC) is an uncommon variant of endometrial carcinoma, and clinicopathological studies have produced conflicting results regarding its biological behavior with 5-year survival ranging from 21 to 75%. The molecular characteristics of endometrioid and serous carcinoma have been studied extensively; however, there have been few molecular genetic studies of the clear cell subtype. In this study, we evaluated 16 UCCs (11 pure and 5 mixed) for mutations in the p53 gene, PTEN gene and for microsatellite instability. Although we found that these alterations were uncommon in pure clear cell carcinomas, all three were identified. In addition, two cases of mixed serous and clear cell carcinoma showed an identical mutation of the p53 gene in the histologically distinct components and one case of mixed clear cell and endometrioid carcinoma had identical mutations in the PTEN and p53 genes, and microsatellite instability in both components. Our data suggest that UCC represent a heterogeneous group of tumors that arise via different pathogenetic pathways. Additional molecular studies of pure clear cell carcinoma are required to further elucidate the genetic pathways involved in its development and progression.

Immunoprofile of ovarian tumors with putative transitional cell (urothelial) differentiation using novel urothelial markers: histogenetic and diagnostic implications.

Ovarian tumors containing cells with transitional cell morphology are recognized in the 1999 World Health Organization classification of ovarian tumors and include benign Brenner tumor, borderline and malignant Brenner tumor, and transitional cell carcinoma. Recent immunohistochemical investigations have reached conflicting conclusions regarding true urothelial differentiation in ovarian Brenner tumors. We evaluated a panel consisting of antibodies to uroplakin III (UROIII), thrombomodulin (THR), cytokeratin 7 (CK7), cytokeratin 20 (CK20), and Wilms' tumor protein (WT1) to study urothelial differentiation in ovarian transitional cell tumors. Additionally, we compared the immunohistochemical profile of transitional cell carcinoma of the ovary (TCC-O) with that of transitional cell carcinoma of the bladder (TCC-B), to ascertain if immunohistochemistry may aid in distinguishing primary from metastatic TCC-O. Seventeen benign Brenner tumors and 17 TCC-O were stained with antibodies to UROIII, THR, CK7, CK20, and WT1. Additionally, 6 Brenner tumors of borderline malignancy were stained with antibodies to UROIII, THR, CK7, and CK20. The immunohistochemical results were compared with those of 30 cases of noninvasive TCC-B (low malignant potential n=14, low grade n=16) and 36 cases of invasive TCC-B stained with a similar panel of antibodies as part of another study. Twenty-one nontransitional cell ovarian carcinomas (9 serous, 4 clear cell, 5 endometrioid, 2 mixed endometrioid/serous, and 1 mucinous) were used as controls. Most Brenner tumors showed positivity with UROIII (82%) and THR (76%), supporting true urothelial differentiation in these tumors. Although TCC-O has considerable morphologic overlap with TCC-B, they had only partial immunophenotypic overlap. TCC-O rarely expressed UROIII (6%) and THR (18%) and none expressed CK20. In contrast, nearly 40% of invasive TCC-B expressed UROIII, 61% expressed THR, and 50% expressed CK20. Nearly 82% of TCC-O expressed WT1, which was negative in all TCC-B. Our results may have diagnostic value in distinguishing TCC-O (CK20-, UROIII-/+, WT1+) and invasive TCC-B (CK20+, UROIII+/-, WT1-) metastatic to the ovary. They also indicate that the morphologic similarity between TCC-O and TCC-B does not indicate any histogenic similarity and, as others have noted, TCC-O is a variant morphology in the spectrum of surface epithelial carcinomas.

Low-grade vulvar and vaginal intraepithelial neoplasia: correlation of histologic features with human papillomavirus DNA detection and MIB-1 immunostaining.

Histologic criteria of low-grade vulvar/vaginal intraepithelial neoplasia (VIN1/VAIN1) are well established; however, a significant interobserver variability in diagnosing VIN1/VAIN1 has been reported. The goal of this study was to evaluate the utility of MIB-1 immunostaining as an adjunct test to increase the diagnostic accuracy in equivocal cases of VIN1/VAIN1. The second goal was to examine the distribution of low- and high-oncogenic risk human papillomaviruses (HPVs) in VIN1/VAIN1 lesions. Consecutive vulvar/vaginal biopsies originally diagnosed as VIN1/VAIN1 (n = 43) or benign (n = 20) were reviewed by two pathologists to obtain a consensus diagnosis. The diagnosis was further confirmed with HPV testing using Short PCR Fragment 10 and Line Probe Assay. MIB-1 immunostaining was performed, and positive staining was defined as a cluster of two or more stained nuclei in the upper two thirds of the epithelial thickness. After verification of the diagnosis using the consensus histologic review and HPV detection as an objective confirmatory test, 31% of cases originally diagnosed as VIN1/VAIN1 were identified as being overdiagnosed. The sensitivity and the specificity of MIB-1 staining for identifying VIN1/VAIN1 were 0.96 and 0.90, respectively. Seventy percent of VIN1 cases were associated with low-risk viral types. In contrast, the majority (84%) of VAIN1 cases were associated with high-risk HPVs. In conclusion, MIB-1 staining is sensitive and specific for identifying VIN1/VAIN1, helpful in verifying the diagnosis in equivocal cases.