Targeting progesterone signaling prevents metastatic ovarian cancer.

Effective cancer prevention requires the discovery and intervention of a factor critical to cancer development. Here we show that ovarian progesterone is a crucial endogenous factor inducing the development of primary tumors progressing to metastatic ovarian cancer in a mouse model of high-grade serous carcinoma (HGSC), the most common and deadliest ovarian cancer type. Blocking progesterone signaling by the pharmacologic inhibitor mifepristone or by genetic deletion of the progesterone receptor (PR) effectively suppressed HGSC development and its peritoneal metastases. Strikingly, mifepristone treatment profoundly improved mouse survival (∼18 human years). Hence, targeting progesterone/PR signaling could offer an effective chemopreventive strategy, particularly in high-risk populations of women carrying a deleterious mutation in the BRCA gene.

In vivo modeling of metastatic human high-grade serous ovarian cancer in mice.

Metastasis is responsible for 90% of human cancer mortality, yet it remains a challenge to model human cancer metastasis in vivo. Here we describe mouse models of high-grade serous ovarian cancer, also known as high-grade serous carcinoma (HGSC), the most common and deadliest human ovarian cancer type. Mice genetically engineered to harbor Dicer1 and Pten inactivation and mutant p53 robustly replicate the peritoneal metastases of human HGSC with complete penetrance. Arising from the fallopian tube, tumors spread to the ovary and metastasize throughout the pelvic and peritoneal cavities, invariably inducing hemorrhagic ascites. Widespread and abundant peritoneal metastases ultimately cause mouse deaths (100%). Besides the phenotypic and histopathological similarities, mouse HGSCs also display marked chromosomal instability, impaired DNA repair, and chemosensitivity. Faithfully recapitulating the clinical metastases as well as molecular and genomic features of human HGSC, this murine model will be valuable for elucidating the mechanisms underlying the development and progression of metastatic ovarian cancer and also for evaluating potential therapies.

Vaginal Squamous Cell Carcinoma Develops in Mice with Conditional Arid1a Loss and Gain of Oncogenic Kras Driven by Progesterone Receptor Cre.

Oncogenic KRAS mutations are a common finding in endometrial cancers. Recent sequencing studies indicate that loss-of-function mutations in the ARID1A gene are enriched in gynecologic malignant tumors. However, neither of these genetic insults alone are sufficient to develop gynecologic cancer. To determine the role of the combined effects of deletion of Arid1a and oncogenic Kras, Arid1aflox/flox mice were crossed with KrasLox-Stop-Lox-G12D/+ mice using progesterone receptor Cre (PgrCre/+). Histologic analysis and immunohistochemistry of survival studies were used to characterize the mutant mouse phenotype. Hormone dependence was evaluated by ovarian hormone depletion and estradiol replacement. Arid1aflox/flox; KrasLox-Stop-Lox-G12D/+; PgrCre/+ mice were euthanized early because of invasive vaginal squamous cell carcinoma. Younger mice had precancerous intraepithelial lesions. Immunohistochemistry supported the pathological diagnosis with abnormal expression and localization of cytokeratin 5, tumor protein P63, cyclin-dependent kinase inhibitor 2A, and Ki-67, the marker of proliferation. Ovarian hormone deletion in Arid1aflox/flox; KrasLox-Stop-Lox-G12D/+; PgrCre/+ mice resulted in atrophic vaginal epithelium without evidence of vaginal tumors. Estradiol replacement in ovarian hormone-depleted Arid1aflox/flox; KrasLox-Stop-Lox-G12D/+; PgrCre/+ mice resulted in lesions that resembled the squamous cell carcinoma in intact mice. Therefore, this mouse can be used to study the transition from benign precursor lesions into invasive vaginal human papillomavirus-independent squamous cell carcinoma, offering insights into progression and pathogenesis of this rare disease.

Evidence of a dual histogenetic pathway of sacrococcygeal teratomas.

AIMS: Sacrococcygeal teratomas are rare tumours that occur most frequently in neonates, although adult cases also occur. The molecular pathogenesis of these tumours and their long-term prognosis is uncertain. We investigated the i(12p) status of a large number of primary sacrococcygeal teratomas in both children and adults, including cases with malignant germ cell tumour elements. METHODS AND RESULTS: Fifty-four sacrococcygeal teratoma specimens from 52 patients were identified, and available follow-up information was obtained. Fluorescence in-situ hybridization analysis was performed to identify isochromosome 12p [i(12p)] abnormalities on paraffin blocks of the tumours. Among the 48 paediatric patients, there were 44 teratomas and four tumours with combined teratoma and yolk sac tumour (one of whom also had primitive neuroectodermal tumour). The teratomas included 37 mature teratomas and 11 immature teratomas (four grade 1, two grade 2, and five grade 3). The 44 teratomas lacking a yolk sac tumour component were all negative for i(12p). The four tumours with a yolk sac tumour component were all positive for i(12p). The four adult cases all lacked non-teratomatous germ cell tumour components, immature elements, and i(12p). Follow-up information was available for 32 patients. Two patients with teratoma had recurrence, but were alive with no evidence of disease after long-term follow-up. One patient with combined teratoma and yolk sac tumour had recurrence 7 months after resection. The other patients were alive with no evidence of disease at last follow-up. CONCLUSIONS: Our data suggest that paediatric sacrococcygeal teratomas should be considered as two distinct groups with divergent histogenetic pathways. The prognosis of these tumours is excellent, despite rare recurrence.

TERT promoter mutation status in sarcomatoid urothelial carcinomas of the upper urinary tract.

AIM: To determine TERT promoter mutation status as well as the expression of PAX8, GATA3, p63, p40, p53 and uroplakin III in 17 patients with the upper urinary tract sarcomatoid urothelial carcinoma. METHODS & RESULTS:  TERT C228T mutations were found in six of 17 cases (35%). p53 was expressed in 77% of these tumors. PAX8, GATA3, p40 and uroplakin III are less frequently expressed. Lymph node metastases were present in ten cases (59%). Eight patients (47%), including all three patients with TERT mutation, died of cancer within 2 years after surgery. CONCLUSION: Sarcomatoid carcinoma of the upper urinary tract is an aggressive tumor and the presence of TERT mutation may portend poor prognosis.

Cervical Carcinomas With Neuroendocrine Differentiation: A Report of 28 Cases With Immunohistochemical Analysis and Molecular Genetic Evidence of Common Clonal Origin With Coexisting Squamous and Adenocarcinomas.

Cervical neuroendocrine carcinomas are rare, aggressive tumors and their immunohistochemical features and clonal relationship to coexisting tumors are incompletely described. Twenty-eight cases were identified (17 small cell, 9 large cell, and 2 mixed), 10 of which had an invasive squamous or adenocarcinoma component. Staining for synaptophysin, chromogranin A, TTF1, c-kit, CD44, and p16 was performed. Analyses for loss of heterozygosity (LOH) at 5 polymorphic microsatellite markers (D3S1300, D9S171, D11S914, D13S319, and TP53) and X-chromosome inactivation were performed. Of 17 cases with available blocks, 13 (76%) were synaptophysin+, 8 (47%) were chromogranin A+, 8 (47%) were TTF1+, 7 (41%) were c-kit+, and 6 (35%) were CD44+. Strong patchy or strong diffuse p16 staining was seen in all cases. LOH and X-chromosome inactivation analysis were performed for 17 cases, 8 of which had a coexisting squamous or adenocarcinoma component. Five of the 8 (63%) cases with 2 components showed allelic loss in both components. All 5 of these cases demonstrated identical LOH between the neuroendocrine and squamous or adenocarcinoma components. Nonrandom X-chromosome inactivation was seen in the neuroendocrine and other components in 4 of the 8 cases. In all 4 cases the pattern of inactivation was identical between the 2 components. Cervical neuroendocrine carcinomas have features similar to other extrapulmonary neuroendocrine carcinomas, including expression of TTF1, c-kit, and CD44. Consistent staining for p16 is also seen. Concordant genetic alterations support common clonal origin for neuroendocrine carcinomas with a coexisting squamous or adenocarcinoma component.

In vivo tumor growth of high-grade serous ovarian cancer cell lines.

OBJECTIVE: Genomic studies of ovarian cancer (OC) cell lines frequently used in research revealed that these cells do not fully represent high-grade serous ovarian cancer (HGSOC), the most common OC histologic type. However, OC lines that appear to genomically resemble HGSOC have not been extensively used and their growth characteristics in murine xenografts are essentially unknown. METHODS: To better understand growth patterns and characteristics of HGSOC cell lines in vivo, CAOV3, COV362, KURAMOCHI, NIH-OVCAR3, OVCAR4, OVCAR5, OVCAR8, OVSAHO, OVKATE, SNU119 and UWB1.289 cells were assessed for tumor formation in nude mice. Cells were injected intraperitoneally (i.p.) or subcutaneously (s.c.) in female athymic nude mice and allowed to grow (maximum of 90 days) and tumor formation was analyzed. All tumors were sectioned and assessed using H&E staining and immunohistochemistry for p53, PAX8 and WT1 expression. RESULTS: Six lines (OVCAR3, OVCAR4, OVCAR5, OVCAR8, CAOV3, and OVSAHO) formed i.p xenografts with HGSOC histology. OVKATE and COV362 formed s.c. tumors only. Rapid tumor formation was observed for OVCAR3, OVCAR5 and OVCAR8, but only OVCAR8 reliably formed ascites. Tumors derived from OVCAR3, OVCAR4, and OVKATE displayed papillary features. Of the 11 lines examined, three (Kuramochi, SNU119 and UWB1.289) were non-tumorigenic. CONCLUSIONS: Our findings help further define which HGSOC cell models reliably generate tumors and/or ascites, critical information for preclinical drug development, validating in vitro findings, imaging and prevention studies by the OC research community.

Distinguishing primary adenocarcinoma of the urinary bladder from secondary involvement by colorectal adenocarcinoma: extended immunohistochemical profiles emphasizing novel markers.

Glandular neoplasms involving the urinary bladder carry a challenging differential diagnosis including primary and secondary processes. We investigated the potential diagnostic utility of cadherin-17 and GATA3 in 25 primary adenocarcinomas of the urinary bladder, as compared with other commonly used markers including ß-catenin and p63. Urothelial carcinoma with glandular differentiation (11), colorectal adenocarcinoma secondarily involving the bladder (25), and primary colorectal adenocarcinoma (22) were also analyzed and the results were compared using a Fisher exact test. Cadherin-17 was expressed in 23/25 primary bladder adenocarcinomas (92%), 23/25 colorectal adenocarcinomas involving the bladder (92%), 21/22 primary colorectal adenocarcinomas (95%) and entirely negative (0/11) in both components of urothelial carcinoma with glandular differentiation (P<0.001). In urothelial carcinoma with glandular differentiation, positive nuclear staining for GATA3 was evident in the urothelial component for 18% (2/11) and the glandular component for 9% (1/11) with additional tumors showing only cytoplasmic staining. Nuclear reactivity for GATA3 was not present in primary bladder adenocarcinoma and primary/secondary colorectal adenocarcinoma (P<0.05). Positive nuclear and cytoplasmic immunostaining for ß-catenin was evident in 21/22 primary colorectal adenocarcinomas (95%) and 23/25 cases of secondary involvement by colorectal adenocarcinoma (92%). In contrast, positive membranous and cytoplasmic staining for ß-catenin was observed in 23/25 primary bladder adenocarcinomas (92%) and 11/11 urothelial carcinomas with glandular differentiation (100%, P<0.001). p63 was expressed only in the urothelial component of urothelial carcinoma with glandular differentiation and not in the glandular component (P<0.001). In summary, cadherin-17 is a relatively specific and sensitive marker for primary adenocarcinoma of the urinary bladder, distinguishing it from urothelial carcinoma with glandular differentiation. However, it does not distinguish primary bladder adenocarcinoma from secondary involvement by colorectal adenocarcinoma. The pattern of reactivity for ß-catenin remains the most useful marker for distinguishing these two tumors.

Schwannomatosis: the overlooked neurofibromatosis?

OBJECTIVE: Schwannomas are typically benign tumors that occur sporadically, in neurofibromatosis type 2 (NF2), or in an entity called "schwannomatosis." Schwannomatosis patients develop multiple schwannomas without involvement of the vestibular apparatus. Geneticists, neurologists, and pathologists have recognized that schwannomatosis is distinct from NF2, but schwannomatosis remains unfamiliar to many radiologists. This article reviews the current medical literature, highlighting the similarities and differences between the schwannomatosis and NF2 phenotypes, genotypes, clinical manifestations, management considerations, and imaging findings. CONCLUSION: Imaging plays a critical role in diagnosing schwannomatosis, and a basic understanding of this syndrome is of interest to diagnostic radiologists. Moreover, it is imperative that radiologists be able to differentiate schwannomatosis from NF2 on imaging because there are significant differences in the management of these two diseases and clinical outcomes for affected patients.

Reclassification of serous ovarian carcinoma by a 2-tier system: a Gynecologic Oncology Group Study.

BACKGROUND: A study was undertaken to use the 2-tier system to reclassify the grade of serous ovarian tumors previously classified using the International Federation of Gynecology and Obstetrics (FIGO) 3-tier system and determine the progression-free survival (PFS) and overall survival (OS) of patients treated on Gynecologic Oncology Group (GOG) Protocol 158. METHODS: The authors retrospectively reviewed demographic, pathologic, and survival data of 290 patients with stage III serous ovarian carcinoma treated with surgery and chemotherapy on GOG Protocol 158, a cooperative multicenter group trial. A blinded pathology review was performed by a panel of 6 gynecologic pathologists to verify histology and regrade tumors using the 2-tier system. The association of tumor grade with PFS and OS was assessed. RESULTS: Of 241 cases, both systems demonstrated substantial agreement when combining FIGO grades 2 and 3 (overall agreement, 95%; kappa statistic, 0.68). By using the 2-tier system, patients with low-grade versus high-grade tumors had significantly longer PFS (45.0 vs 19.8 months, respectively; P = .01). By using FIGO criteria, median PFS for patients with grade 1, 2, and 3 tumors was 37.5, 19.8, and 20.1 months, respectively (P = .07). There was no difference in clinical outcome in patients with grade 2 or 3 tumors in multivariate analysis. Woman with high-grade versus low-grade tumors demonstrated significantly higher risk of death (hazard ratio, 2.43; 95% confidence interval, 1.17-5.04; P = .02). CONCLUSIONS: Women with high-grade versus low-grade serous carcinoma of the ovary are 2 distinct patient populations. Adoption of the 2-tier grading system provides a simple yet precise framework for predicting clinical outcomes.

p16 expression is not associated with human papillomavirus in urinary bladder squamous cell carcinoma.

Squamous cell carcinoma of the urinary bladder is unusual and of unknown etiology. There is a well-established association between human papillomavirus (HPV) infection and the development of cervical and head/neck squamous cell carcinomas. However, the role of HPV in the pathogenesis of squamous cell carcinoma of the urinary bladder is uncertain. The purposes of this study were to investigate the possible role of HPV in the development of squamous cell carcinoma of the urinary bladder and to determine if p16 expression could serve as a surrogate marker for HPV in this malignancy. In all, 42 cases of squamous cell carcinoma of the urinary bladder and 27 cases of urothelial carcinoma with squamous differentiation were investigated. HPV infection was analyzed by both in situ hybridization at the DNA level and immunohistochemistry at the protein level. p16 protein expression was analyzed by immunohistochemistry. HPV DNA and protein were not detected in 42 cases of squamous cell carcinoma (0%, 0/42) or 27 cases of urothelial carcinoma with squamous differentiation (0%, 0/15). p16 expression was detected in 13 cases (31%, 13/42) of squamous cell carcinoma and 9 cases (33%, 9/27) of urothelial carcinoma with squamous differentiation. There was no correlation between p16 expression and the presence of HPV infection in squamous cell carcinoma of the bladder or urothelial carcinoma with squamous differentiation. Our data suggest that HPV does not play a role in the development of squamous cell carcinoma of the urinary bladder or urothelial carcinoma with squamous differentiation. p16 expression should not be used as a surrogate marker for evidence of HVP infection in either squamous cell carcinoma of the urinary bladder or urothelial carcinoma with squamous differentiation as neither HVP DNA nor protein is detectable in these neoplasms.

Endoscopic ultrasound-guided Trucut biopsy of gastrointestinal mesenchymal tumor.

BACKGROUND: Data on the utility of endoscopic ultrasound-guided Trucut biopsy (EUS-TCB) for suspected gastrointestinal mesenchymal tumor (GIMT) are limited. This study aimed to determine the diagnostic yield and complications from EUS-TCB for GIMT. METHODS: Consecutive patients with suspected upper gastrointestinal or rectal GIMT from the muscularis propria with a maximal diameter of 20 mm or more were enrolled in a prospective, single-center cohort. An EUS-TCB was performed when on-site fine-needle aspiration (FNA) cytology review of the lesion was deemed suboptimal. Gastrointestinal stromal tumor (GIST) and leiomyoma were defined by the presence or absence of positive immunochemistry (IC) for c-kit, respectively. All GIMTs with a nondiagnostic IC were considered as unspecified. The outcomes assessed included diagnostic pathologic and IC yield (when tested) and procedural complications. RESULTS: In this study, 38 patients (24 women; median age, 62 years) with suspected GIMT (median maximal diameter, 42 mm; range, 20-120 mm) in the esophagus (n=6), stomach (n=28), duodenum (n=3), or rectum (n=1) underwent EUS-TCB without complications. Final diagnoses included GIST for 20 patients, leiomyoma for 13 patients, unspecified GIMT for 3 patients, and unknown disorder for 2 patients. An EUS-FNA was performed for 33 (87%) of the 38 patients, a diagnostic final cytology for 25 (76%) of 33 patients, and an FNA-IC for 12 (50%) of 24 patients. The EUS-TCB (median, 3 passes; range, 1-8 passes) obtained a visible tissue specimen in 37 (97%) of the 38 patients, with a median overall maximal fragment length of 3.5 mm (range, 0-15 mm). The diagnostic final TCB histology and TCB-IC were obtained, respectively, in 79 and 97% of the samples tested. CONCLUSIONS: In this cohort, EUS-TCB provided diagnostic histology and IC for 79 and 97% of the patients, respectively. For the initial biopsy of GIMT, EUS-TCB may be considered an acceptable alternative to EUS-FNA.

A Novel ZIP4-HDAC4-VEGFA Axis in High-Grade Serous Ovarian Cancer.

We have recently identified ZIP4 as a novel cancer stem cell (CSC) marker in high-grade serous ovarian cancer (HGSOC). While it converts drug-resistance to cisplatin (CDDP), we unexpectedly found that ZIP4 induced sensitization of HGSOC cells to histone deacetylase inhibitors (HDACis). Mechanistically, ZIP4 selectively upregulated HDAC IIa HDACs, with little or no effect on HDACs in other classes. HDAC4 knockdown (KD) and LMK-235 inhibited spheroid formation in vitro and tumorigenesis in vivo, with hypoxia inducible factor-1 alpha (HIF1α) and endothelial growth factor A (VEGFA) as functional downstream mediators of HDAC4. Moreover, we found that ZIP4, HDAC4, and HIF1α were involved in regulating secreted VEGFA in HGSOC cells. Furthermore, we tested our hypothesis that co-targeting CSC via the ZIP4-HDAC4 axis and non-CSC using CDDP is necessary and highly effective by comparing the effects of ZIP4-knockout/KD, HDAC4-KD, and HDACis, in the presence or absence of CDDP on tumorigenesis in mouse models. Our results showed that the co-targeting strategy was highly effective. Finally, data from human HGSOC tissues showed that ZIP4 and HDAC4 were upregulated in a subset of recurrent tumors, justifying the clinical relevance of the study. In summary, our study provides a new mechanistic-based targeting strategy for HGSOC.

Methylomic Signatures of High Grade Serous Ovarian Cancer.

High-grade serous ovarian cancer (HGSOC) harbours aberrant epigenetic features, including DNA methylation. In this study we delineate pathways and networks altered by DNA methylation and associated with HGSOC initiation and progression to a platinum-resistant state. By including tumours from patients who had been treated with the hypomethylating agent (HMA) guadecitabine, we also addressed the role of HMAs in treatment of HGSOC. Tumours from patients with primary (platinum-naïve) HGSOC (n = 20) were compared to patients with recurrent platinum-resistant HGSOC and enrolled in a recently completed clinical trial (NCT01696032). Human ovarian surface epithelial cells (HOSE; n = 5 samples) served as normal controls. Genome-wide methylation profiles were determined. DNA methyltransferase (DNMT) expression levels were examined by immunohistochemistry and correlated with clinical outcomes. Cancer-related and tumorigenesis networks were enriched among differentially methylated genes (DMGs) in primary OC vs. HOSE. When comparing platinum-resistant and primary tumours, 452 CpG island (CGI)-containing gene promoters acquired DNA methylation; of those loci, decreased (P < 0.01) methylation after HMA treatment was observed in 42% (n = 189 CGI). Stem cell pluripotency and cytokine networks were enriched in recurrent platinum-resistant OC tumours, while drug metabolism and transport-related networks were downregulated in tumours from HMA-treated patients compared to HOSE. Lower DNMT1 and 3B protein levels in pre-treatment tumours were associated with improved progression-free survival. The findings provide important insight into the DNA methylation landscape of HGSOC tumorigenesis, platinum resistance and epigenetic resensitization. Epigenetic reprogramming plays an important role in HGSOC aetiology and contributes to clinical outcomes.

ZIP4 Is a Novel Cancer Stem Cell Marker in High-Grade Serous Ovarian Cancer.

High-grade serous ovarian cancer (HGSOC) is one of the most deadly and heterogenic cancers. We have recently shown that ZIP4 (gene name SLC39A4), a zinc transporter, is functionally involved in cancer stem cell (CSC)-related cellular activities in HGSOC. Here, we identified ZIP4 as a novel CSC marker in HGSOC. Fluorescence-activated cell sorter (FACS)-sorted ZIP4+, but not ZIP4- cells, formed spheroids and displayed self-renewing and differentiation abilities. Over-expression of ZIP4 conferred drug resistance properties in vitro. ZIP4+, but not ZIP4- cells, formed tumors/ascites in vivo. We conducted limiting dilution experiments and showed that 100-200 ZIP4+ cells from both PE04 and PEA2 cells formed larger tumors than those from 100-200 ALDH+ cells in mice. Mechanistically, we found that ZIP4 was an upstream regulator of another CSC-marker, NOTCH3, in HGSOC cells. NOTCH3 was functionally involved in spheroid formation in vitro and tumorigenesis in vivo in HGSOC. Genetic compensation studies showed that NOTCH3, but not NOTCH1, was a critical downstream mediator of ZIP4. Furthermore, NOTCH3, but not NOTCH1, physically bound to ZIP4. Collectively, our data suggest that ZIP4 is a novel CSC marker and the new ZIP4-NOTCH3 axis represents important therapeutic targets in HGSOC.

Pten and Dicer1 loss in the mouse uterus causes poorly differentiated endometrial adenocarcinoma.

Endometrial cancer remains the most common gynecological malignancy in the United States. While the loss of the tumor suppressor, PTEN (phosphatase and tensin homolog), is well studied in endometrial cancer, recent studies suggest that DICER1, the endoribonuclease responsible for miRNA genesis, also plays a significant role in endometrial adenocarcinoma. Conditional uterine deletion of Dicer1 and Pten in mice resulted in poorly differentiated endometrial adenocarcinomas, which expressed Napsin A and HNF1B (hepatocyte nuclear factor 1 homeobox B), markers of clear-cell adenocarcinoma. Adenocarcinomas were hormone-independent. Treatment with progesterone did not mitigate poorly differentiated adenocarcinoma, nor did it affect adnexal metastasis. Transcriptomic analyses of DICER1 deleted uteri or Ishikawa cells revealed unique transcriptomic profiles and global miRNA downregulation. Computational integration of miRNA with mRNA targets revealed deregulated let-7 and miR-16 target genes, similar to published human DICER1-mutant endometrial cancers from TCGA (The Cancer Genome Atlas). Similar to human endometrial cancers, tumors exhibited dysregulation of ephrin-receptor signaling and transforming growth factor-beta signaling pathways. LIM kinase 2 (LIMK2), an essential molecule in p21 signal transduction, was significantly upregulated and represents a novel mechanism for hormone-independent pathogenesis of endometrial adenocarcinoma. This preclinical mouse model represents the first genetically engineered mouse model of poorly differentiated endometrial adenocarcinoma.

Molecular Testing for EGFR Mutations and ALK Rearrangements in the Cytological Specimens From the Patients With Non-Small Cell Lung Cancer.

OBJECTIVE: The aim of this study was to investigate epidermal growth factor receptor (EGFR) gene mutations and anaplastic lymphoma kinase (ALK) gene rearrangements using cytological specimens from the patients with a diagnosis of primary or metastatic lung non-small cell carcinoma. MATERIALS AND METHODS: A total 307 cases were submitted for EGFR mutational analysis and 265 cases for ALK analysis. The cytological specimen sources included lung, lymph node, liver, bone, adrenal gland, mesentery mass, and body fluids/bronchial brushing. EGFR mutations in the exons 18 to 21 were analyzed with Qiagen EGFR Pyro Kits. Fluorescence in situ hybridization (FISH) studies for ALK rearrangement inv(2)(p21; p23) were performed on the paraffin-embedded cell block sections utilizing dual-color Vysis LSI ALK Break Apart Probe Kit. RESULTS: Among 307 fine needle aspirate cases for EGFR analysis, 302 cases (269 from cell blocks, 33 from direct smears) had sufficient material for EGFR test. Five cases failed due to inadequate cellularity. Twenty six of 302 (8.6%) cases were positive for EGFR mutations. A total of 265 cases submitted for ALK analysis included 240 cases of fine needle aspirate, 25 cases of pleural fluid/pericardial fluid/bronchial washings. Eight cases failed because of low cellularity, whereas 257 of 265 cases had sufficient material for ALK FISH study. Nine of 257 cases (3.5%) revealed ALK rearrangement by FISH. CONCLUSIONS: The current study demonstrates that cytological specimens can yield sufficient material for EGFR mutations and ALK rearrangement test. Our study reveals that 8.6% of EGFR mutation rate and 3.5% of ALK rearrangement rate in the cytology specimens from the patients with primary or metastatic lung non-small cell carcinoma.

Solitary fibrous tumor.

Solitary fibrous tumor (SFT) is a rare tumor of mesenchymal origin that account for less than 2% of all soft tissue masses. Initially identified in the pleura, SFT has been identified in multiple anatomic locations and can arise anywhere in the body. The varying histologic features along with non-specific means of identification have led SFT to be associated with several different names. Over the last several decades, sustained advances through research and technology have led to more reliable methods for differentiating this distinct soft tissue tumor. Advances specifically in immunohistochemistry and molecular diagnostics have identified CD34 as the most consistent marker in SFT, however even this lacks specificity to conclusively narrow down the broad differential for exact identification. More recently the discovery of the NAB2-STAT6 fusion gene has led to more precise diagnosis of SFT. Like many other soft tissue tumors, surgical management is the mainstay of treatment for SFT with emphasis on obtaining tumor-negative margins. Radiation therapy and chemotherapy regimens have not demonstrated global effectiveness, and thus no standardized treatments have been identified. Given the rarity of SFT and current supportive evidence for therapies, management should be focused on tumor extirpation. Nonetheless, individualized therapy, determined within a multidisciplinary setting should be considered.

Small-cell Carcinomas of the Urinary Bladder and Prostate: TERT Promoter Mutation Status Differentiates Sites of Malignancy and Provides Evidence of Common Clonality Between Small-cell Carcinoma of the Urinary Bladder and Urothelial Carcinoma.

BACKGROUND: Small-cell carcinoma (SCC) of the urinary bladder frequently appears alongside urothelial carcinoma, suggesting common clonality. TERT promoter mutations have been recently implicated in urothelial carcinogenesis. OBJECTIVE: To investigate the degree to which TERT promoter mutations are involved in SCC of the urinary bladder, the linked tumorigenesis between urothelial carcinoma and SCC of the urinary bladder, and the molecular distinctions between SCC of the urinary bladder and of the prostate. DESIGN, SETTING, AND PARTICIPANTS: We investigated TERT promoter mutations in 53 cases of SCC of the urinary bladder and in 26 cases of SCC of the prostate using laboratory-based studies of tissue samples and clinical data. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We measured the frequency of TERT promoter mutations in SCCs of the urinary bladder and prostate, and concordance of the mutation status between concurrent urinary bladder SCC and urothelial carcinoma. RESULTS AND LIMITATIONS: TERT promoter mutations were detected in 29/53 (55%) cases of urinary bladder and 0/26 (0%) cases of prostate SCC. Of 25 cases with concurrent urinary bladder SCC and non-small-cell components, all cases harbored identical TERT promoter mutation status in both phenotypes. CONCLUSIONS: TERT promoter mutations are found in more than half of urinary bladder SCCs. Mutation status is also identical in urothelial carcinoma and SCC components of concomitant malignancies, providing evidence of a common clonality. TERT promoter mutation status can differentiate SCC of the urinary bladder from prostate SCC, suggesting potential diagnostic use. PATIENT SUMMARY: Small-cell carcinoma of the urinary bladder shares a common clonal origin with conventional urothelial carcinoma and may arise from a heterogeneous subclone. TERT promoter mutations may have utility as a differential biomarker for determining the primary site of a genitourinary small-cell carcinoma.

Morphological approach to tumours of the testis and paratestis.

Most neoplastic scrotal masses ultimately prove to be germ cell tumours and are recognisable with routine haematoxylin and eosin-stained sections. The differential diagnosis may be focused, even before reviewing histological sections, by knowledge of patient age, medical history, tumour site (testicular vs paratesticular) and gross findings. Some cases may prove to be diagnostically challenging, including rare tumours, a common tumour with an unusual pattern, a metastatic tumour, or a neoplasm with features that mimic another tumour. Several morphological patterns are seen with some frequency and these generate recurring sets of differential diagnostic considerations. These common patterns include testicular tumours with a predominant diffuse arrangement of cells with pale to clear cytoplasm, tumours with a glandular/tubular pattern, tumours with a microcystic pattern and tumours composed of oxyphilic cells. Intratubular proliferations of atypical cells, paratesticular glandular and/or papillary tumours, or tumours with spindle cell morphology can also be challenging to diagnose correctly. In some problematic cases, immunohistochemical staining may be useful to resolve these differential diagnoses.