Injuries from exposure to explosions rose dramatically during the Iraq and Afghanistan wars, which motivated investigations of blast-related neurotrauma and operational breaching. In this study, military "breachers" were exposed to controlled, low-level blast during a 10-day explosive breaching course. Using an omics approach, we assessed epigenetic, transcriptional, and inflammatory profile changes in blood from operational breaching trainees, with varying levels of lifetime blast exposure, along with daily self-reported symptoms (with tinnitus, headaches, and sleep disturbances as the most frequently reported). Although acute exposure to blast did not confer epigenetic changes, specifically in DNA methylation, differentially methylated regions (DMRs) with coordinated gene expression changes associated with chronic lifetime cumulative blast exposures were identified. The accumulative effect of blast showed increased methylation of PAX8 antisense transcript with coordinated repression of gene expression, which has been associated with sleep disturbance. DNA methylation analyses conducted in conjunction with reported symptoms of tinnitus in the low vs. high blast incidents groups identified DMRS in KCNE1 and CYP2E1 genes. KCNE1 and CYP2E1 showed the expected inverse correlation between DNA methylation and gene expression, which have been previously implicated in noise related hearing loss. Although no significant transcriptional changes were observed in samples obtained at the onset of the training course relative to chronic cumulative blast, we identified a large number of transcriptional perturbations acutely pre- versus post-blast exposure. Acutely, 67 robustly differentially expressed genes (fold change ≥1.5), including UFC1 and YOD1, ubiquitin-related proteins were identified. Inflammatory analyses of cytokines and chemokines revealed dysregulation of MCP-1, GCSF, HGF, MCSF, and RANTES acutely following blast exposure. These data show the importance of an omics approach, revealing that transcriptional and inflammatory biomarkers capture acute low-level blast overpressure exposure, whereas DNA methylation marks encapsulate chronic long-term symptoms. Keywords: Epigenetics; blast overpressure; traumatic brain injury; tinnitus; sleep.

PAX8 has emerged as a useful immunohistochemical marker for epithelial neoplasms of gynecologic origin. Expression of PAX8 in uterine malignant mesodermal mixed tumors (MMMT, carcinosarcoma) has not been characterized in detail. The goal of this study is to evaluate PAX8 expression in uterine MMMTs, with particular attention to its distribution in specific tumor components. Thirty-seven cases were studied. PAX8 expression was assessed by immunohistochemistry and scored separately in the epithelial and mesenchymal components of the tumors. The extent of staining was scored based on the estimated percentage of positive tumor cells as 1+: 1% to 25%; 2+: 26% to 50%; 3+: 51% to 75%; 4+: 76% to 100%. The epithelial component expressed PAX8 in all but 1 tumor, with 92% of tumors displaying 3+ and 4+ extent of staining. The mesenchymal component lacked PAX8 expression in 27 cases (73%) with variable expression in the remaining 10 cases. In addition, 12 tumors contained undifferentiated areas that were not readily classifiable as carcinoma or sarcoma based on morphologic features. Of these, 8 (67%) were negative for PAX8, whereas 4 (33%) demonstrated variable extent of expression. Thus, PAX8 is expressed in the carcinomatous components of nearly all uterine MMMTs (97%), with expression in sarcomatous and undifferentiated components being less common and less extensive. The uniform, extensive expression in the carcinomatous components makes PAX8 a useful marker for diagnosis of carcinomatous metastases of uterine MMMT at extrauterine sites. Its infrequent expression in the sarcomatous and undifferentiated components limits its utility in identifying sarcoma-predominant metastases as gynecologic in origin.

Paired box (PAX) gene antibodies have made it into the mainstream of tumor diagnosis in the recent years. We report the immunoreactivity expression patterns of three PAX genes (PAX2, PAX5 and PAX8) in poorly differentiated small round cell tumors of childhood for possible useful diagnostic applications. We collected and analyzed 123 cases of poorly differentiated small round cell tumors of childhood for their PAX immunoexpression patterns. The results indicated that PAX2 was strongly positive in all alveolar rhabdomyosarcomas and in two-thirds of the kidney clear cell sarcomas, and displayed variable expression in one-half of the embryonal rhabdomyosarcomas. PAX8 immunoexpression was noticed in five and three cases of alveolar rhabdomyosarcomas and embryonal rhabdomyosarcomas, respectively. About one-third of malignant rhabdoid tumors were PAX2-positive and PAX8-positive. All of the Ewing sarcoma and neuroblastoma cases stained negative with all three PAX stains.

Single nucleotide polymorphisms (SNPs) in miRNAs are associated with the risk to development of certain human diseases and affect the regulatory capacity of miRNAs. However, the relationship between miRNAs polymorphisms and recurrent pregnancy loss (RPL) is still largely unknown. Our study found that one SNP rs56103835 T>C in miR-323b coding region was associated with the increase risk of human unexplained RPL (URPL), but no differences were found in another SNP rs75330474 C>T. However, in two-locus haplotype analysis, T-C haplotype was associated with an increased risk of URPL. The level of mature miR-323b was obviously up-regulated in cells transfected with T-C haplotype. T-C haplotype inhibited HTR-8/SVneo cells proliferation and migration and promoted cells apoptosis. Further experiments identified that paired-box 8 (Pax8) was a functionally relevant target of miR-323b, and its expression was reversely regulated by miR-323b. Besides, the expressions of Pax8 in villous chorionic tissues from URPL patients were lower than controls, contrary to the high expression of miR-323. More importantly, dual-luciferase assay indicated T-C haplotype, increasing miR-323b expression, could down-regulated Pax8 expression. Collectively, our data suggest that T-C haplotype in pre-miR-323b may aggravate the risk of developing URPL and influence the level of mature miR-323b and its target gene Pax8.

Recent methodology has enabled the identification of some new genetic subgroups within the melting pot of lesions presently classified by the 2013 WHO classification as "undifferentiated/unclassified sarcomas". One of these subgroups is characterized by a paracentric inversion of the X chromosome with consequent formation of a BCOR-CCNB3 fusion. Clinical and pathological features of these tumors overlap with the Ewing sarcoma family as well as other soft tissue sarcomas, thus making them difficult to diagnose. To investigate the morphological and immunohistochemical characteristics of BCOR-CCNB3 positive sarcoma, we reviewed two sarcoma series, comprising 632 and 121 cases. The 11 tumors harboring the BCOR-CCNB3 fusion, identified by CCNB3 immunohistochemistry and/or RT-PCR, were reevaluated for morphological characteristics and further immunohistochemical investigations for CCNB3, SATB2, and Pax8 were performed. Tumors harboring a BCOR-CCNB3 fusion (11/753) occured exclusively in males, with a mean age at diagnosis of 12.9 years, and were mainly axially located. In this group of either spindled or round cell tumors, vesicular nuclei with finely dispersed chromatin, inconspicuous nucleoli and an arciform vascular pattern were pathognomonic. More than 50% of cases stained positive for SATB2 and Pax8, raising the hypothesis of a potential use of these markers in the identification of BCOR-CCNB3 positive undifferentiated/unclassified sarcomas. CCNB3 was confirmed as a useful ancillary immunohistochemical marker.

The clinical importance of anterior foregut endoderm (AFE) derivatives, such as thyrocytes, has led to intense research efforts for their derivation through directed differentiation of pluripotent stem cells (PSCs). Here, we identify transient overexpression of the transcription factor (TF) NKX2-1 as a powerful inductive signal for the robust derivation of thyrocyte-like cells from mouse PSC-derived AFE. This effect is highly developmental stage specific and dependent on FOXA2 expression levels and precise modulation of BMP and FGF signaling. The majority of the resulting cells express thyroid TFs (Nkx2-1, Pax8, Foxe1, Hhex) and thyroid hormone synthesis-related genes (Tg, Tpo, Nis, Iyd) at levels similar to adult mouse thyroid and give rise to functional follicle-like epithelial structures in Matrigel culture. Our findings demonstrate that NKX2-1 overexpression converts AFE to thyroid epithelium in a developmental time-sensitive manner and suggest a general methodology for manipulation of cell-fate decisions of developmental intermediates.

The present case-control study was conducted on 110 children with acute lymphoblastic leukemia (ALL) and 120 healthy children to determine the impact of polymorphisms in paired-box gene 8 (PAX8) antisense RNA 1 (PAX8-AS1), namely rs4848320 C>T, rs6726151 T>G and rs1110839 G>T, on ALL risk. Genotyping was performed through the polymerase chain reaction-restriction fragment length polymorphism method. The findings indicated that the rs4848320 variant increased the risk of ALL in codominant [CT vs. CC: odds ratio (OR)=2.13, 95% confidence interval (CI)=1.16-3.90, P=0.014; and TT vs. CC: OR=2.21, 95% CI=1.03-4.74, P=0.041], dominant (CT+TT vs. CC: OR=2.15, 95% CI=1.22-3.81, P=0.009,) and allele (T vs. C: OR=1.55, 95% CI=1.07-2.25, P=0.024) inheritance models. The rs6726151 variant significantly increased the risk of ALL in codominant (GT vs. GG: OR=1.88, 95% CI=1.08-3.27, P=0.036) and overdominant (GT vs. GG+TT: OR=2.08, 95% CI=1.23-3.53, P=0.008) inheritance models. No significant relationship was identified between the rs1110839 G>T variant and disease risk/protection in childhood ALL. In conclusion, the findings of the present study indicated that rs4848320 and rs6726151 polymorphisms of PAX8-AS1 may be a risk factor for the development of childhood ALL. Further studies with larger sample sizes and different ethnicities are now required to confirm these findings.

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology category of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) includes fine-needle aspiration (FNA) specimens that cannot straightforwardly be classified as benign or malignant. To determine whether morphological subcategorization based on atypia qualifiers and molecular testing could improve malignancy risk stratification of AUS/FLUS patients, this study assessed the correlation between these qualifiers and the molecular alterations commonly harbored by thyroid neoplasms.

METHODS

A total of 162 AUS/FLUS cases were subcategorized by atypia qualifiers (Hürthle cell changes, architectural atypia, and cytologic atypia [CyA]) and were tested for BRAF, N-H-KRAS, RET/PTC, and paired box 8 (PAX8)/peroxisome proliferator activated receptor γ (PPARg) mutations.

RESULTS

CyA was observed more frequently in mutation-positive AUS/FLUS (14 of 37 [37.84%]) than mutation-negative AUS/FLUS (20 of 125 [16.00%]; P < .0084), and it specifically harbored the BRAFV600E point mutation. Malignancy was confirmed in the available follow-up. Conversely, although RAS was the most frequent mutation identified in AUS/FLUS FNA specimens (26 of 37 cases [70.27%]; P < .0001), it was distributed across various AUS/FLUS subcategories and was not significantly associated with a specific atypia qualifier or malignant outcome according to the available follow-up. Rearrangements of both RET/PTC (n = 1) and PAX8/PPARg (n = 3) were rarely retrieved in the FNA samples.

CONCLUSIONS

BRAF and RAS mutations are associated with different AUS/FLUS qualifiers and hence have different risks of malignancy. Consequently, a hybrid molecular and morphological subcategorization system could improve the malignancy risk stratification of thyroid FNA samples diagnosed as AUS/FLUS. Cancer Cytopathol 2018;126:317-25. © 2018 American Cancer Society.

The inhibitory mechanisms that prevent gene expression programs from one tissue to be expressed in another are poorly understood. Foxp1/2/4 are forkhead transcription factors that repress gene expression and are individually important for endoderm development. We show that combined loss of all three Foxp1/2/4 family members in the developing anterior foregut endoderm leads to a loss of lung endoderm lineage commitment and subsequent development. Foxp1/2/4 deficient lungs express high levels of transcriptional regulators not normally expressed in the developing lung, including Pax2, Pax8, Pax9 and the Hoxa9-13 cluster. Ectopic expression of these transcriptional regulators is accompanied by decreased expression of lung restricted transcription factors including Nkx2-1, Sox2, and Sox9. Foxp1 binds to conserved forkhead DNA binding sites within the Hoxa9-13 cluster, indicating a direct repression mechanism. Thus, Foxp1/2/4 are essential for promoting lung endoderm development by repressing expression of non-pulmonary transcription factors.

BACKGROUND

Typically, thyroid follicular neoplasm/suspicious for follicular neoplasm (FN/SFN) cases show moderate to marked cellularity and scant or absent colloid. Recently, cases have been noted with microfollicular cellularity in the background of moderate to abundant amount of colloid. The purpose of this study was to compare these "colloid-rich" FN/SFN cases to the typical FN/SFN cases.

METHODS

Thyroid cytology specimens with the features of FN/SFN were searched in cytopathology files from September 2008 to June 2012. Cases with absent or minimal colloid were designated "typical colloid-poor" FN/SFN and cases with moderate to abundant colloid were designated "colloid-rich" FN/SFN. From these cases, those with surgical pathology resection follow-up were identified. Cytologic, surgical pathology resection, and molecular features (BRAF, RAS, RET/PTC, and PAX8-PPARγ) were investigated for the typical colloid-poor FN/SFN cases and were compared with those of the colloid-rich FN/SFN cases.

RESULTS

Of 431 FN/SFN cases with surgical pathology resection follow-up, 360 (83.5%) cases showed features of typical colloid-poor FN/SFN and 71 (16.5%) cases showed features of colloid-rich FN/SFN. Papillary carcinoma was the most common malignant outcome for the 2 groups. Although the proportion of malignant outcome was similar for the 2 groups, the "colloid-rich" FN/SFN cases showed a greater proportion of nodular hyperplasia among the cases with benign outcome. In addition, the "colloid-rich" FN/SFN cases demonstrated a greater proportion of cases with a mutation.

CONCLUSIONS

Approximately one-sixth of cases of FN/SFN show "colloid-rich" features. Comparison to the typical colloid-poor FN/SFN demonstrated similar risk for malignancy but contrasting resection outcome and molecular characteristics.

BACKGROUND

Considering the high prevalence of female genital tract neoplasms, non-specific nature of the initial symptoms, higher possibility of metastasis by the time of diagnosis, importance of differentiating metastatic Mullerian tumors or metastatic breast cancer in the female genital tract, especially in the ovary, and lack of diagnostic markers with high sensitivity and specificity, the purpose of the current study was to evaluate the utility of Paired box protein8 (PAX8) expression in Mullerian and non-Mullerian neoplasms.

METHODS

In this descriptive-analytic, cross-sectional study, paraffin-embedded tissues of patients with definitive pathologic diagnosis of Mullerian and non-Mullerian tumors were selected. PAX8 immunohistochemical (IHC) staining was performed for all selected blocks. Immunopositivity of the slides for PAX8 was reviewed. It was defined as the presence of nuclear staining in at least 10% of the tumor cell nuclei.

RESULTS

Thirty-seven Mullerian (including 18 ovarian epithelial tumors, 17 endometrial carcinoma and two endocervical adenocarcinoma) and 37 non-Mullerian tumors were studied for PAX8 expression. Twenty-nine of 37 (78.4%) and one of 37 (2.7%) of the Mullerian and non-Mullerian tumors were positive for PAX8, respectively. The sensitivity and specificity of PAX8 by IHC for differentiation of Mullerian from non-Mullerian tumors was 78.4% and 97.3%, respectively.

CONCLUSIONS

Our findings indicated that PAX8 could be used as a useful IHC marker for diagnosing Mullerian tumors. It has moderate to high sensitivity, but high specificity, for diagnosing carcinomas of Mullerian origin.

Na⁺/H⁺ exchanger isoform 3 (NHE3) contributes to Na⁺/bicarbonate reabsorption and ammonium secretion in early proximal tubules. To determine its role in the diabetic kidney, type 1 diabetic Akita mice with tubular NHE3 knockdown [Pax8-Cre; NHE3-knockout (KO) mice] were generated. NHE3-KO mice had higher urine pH, more bicarbonaturia, and compensating increases in renal mRNA expression for genes associated with generation of ammonium, bicarbonate, and glucose (phosphoenolpyruvate carboxykinase) in proximal tubules and H⁺ and ammonia secretion and glycolysis in distal tubules. This left blood pH and bicarbonate unaffected in nondiabetic and diabetic NHE3-KO versus wild-type mice but was associated with renal upregulation of proinflammatory markers. Higher renal phosphoenolpyruvate carboxykinase expression in NHE3-KO mice was associated with lower Na⁺-glucose cotransporter (SGLT)2 and higher SGLT1 expression, indicating a downward tubular shift in Na⁺ and glucose reabsorption. NHE3-KO was associated with lesser kidney weight and glomerular filtration rate (GFR) independent of diabetes and prevented diabetes-associated albuminuria. NHE3-KO, however, did not attenuate hyperglycemia or prevent diabetes from increasing kidney weight and GFR. Higher renal gluconeogenesis may explain similar hyperglycemia despite lower SGLT2 expression and higher glucosuria in diabetic NHE3-KO versus wild-type mice; stronger SGLT1 engagement could have affected kidney weight and GFR responses. Chronic kidney disease in humans is associated with reduced urinary excretion of metabolites of branched-chain amino acids and the tricarboxylic acid cycle, a pattern mimicked in diabetic wild-type mice. This pattern was reversed in nondiabetic NHE3-KO mice, possibly reflecting branched-chain amino acids use for ammoniagenesis and tricarboxylic acid cycle upregulation to support formation of ammonia, bicarbonate, and glucose in proximal tubule. NHE3-KO, however, did not prevent the diabetes-induced urinary downregulation in these metabolites.

The incidence of renal cell carcinoma (RCC) is known to be higher in patients with end-stage renal disease, including those with acquired cystic kidney disease due to dialysis. Acquired cystic disease (ACD)-associated RCC was recently incorporated into the 2016 WHO Classification of Tumors of the Urinary System and Male Genital Tract as a distinct entity and is reportedly the most common RCC arising in end-stage renal disease. In this study, we sought to further describe clinicopathologic findings in a large series of ACD-RCC, emphasizing histologic features, immunophenotype, clinical outcome, and patterns of disease spread. We collected 40 previously unpublished cases of ACD-RCC with mean clinical follow-up of 27 months (median, 19 mo; range, 1 to 126 mo). Mean tumor size was 2.7 cm (median, 2.4 cm), and 32 tumors (80%) were confined to the kidney (pT stage less than pT3a). International Society of Urological Pathology grade was 3 in 37 cases (92.5%), grade 2 in 1 case (2.5%), and grade 4 in 2 cases (5%). Architectural variability among ACD-RCC was common, as 39 cases (98%) showed varying combinations of tubular, cystic, solid, and/or papillary growth. ACD-RCC frequently occurred in association with other renal tumor subtypes within the same kidney, including papillary RCC (14 patients), papillary adenomas (7 cases), clear cell papillary RCC (5 cases), clear cell RCC (1 case), and RCC, unclassified type (1 case). A previously undescribed pattern of perinephric and renal sinus adipose tissue involvement by dilated epithelial cysts with minimal or absent intervening capsule or renal parenchyma was identified in 20 cases (50%); these cysts were part of the tumor itself in 5 cases (25%) and were part of the non-neoplastic acquired cystic change in the background kidney in the remaining 15 cases (75%). Of the 24 cases (60%) with tissue available for immunohistochemical stains, 19 (79%) were positive for PAX8, 20 (83%) showed negative to patchy expression of cytokeratin 7, and 24 (100%) were both positive for AMACR and negative for CD117. Fumarate hydratase expression was retained in all tumors, including those with nuclear features resembling fumarate hydratase-deficient RCCs. Of the 36 patients (90%) with available follow-up information, 4 (11%) experienced adverse events: 2 patients developed a local recurrence, 1 patient experienced multiple visceral metastases and subsequently died of disease, and 1 patient developed metastases to regional lymph nodes only. One local recurrence and the lymph node only metastasis both had an unusual, exclusively cystic pattern of growth. In summary, we present the largest clinicopathologic series of ACD-RCC to date and describe previously unreported cystic patterns of local soft tissue involvement and recurrence/metastases.

Genetically relevant mouse models need to recapitulate the hallmarks of human disease by permitting spatiotemporal gene targeting. This is especially important for replicating the biology of complex diseases like cancer, where genetic events occur in a sporadic fashion within developed somatic tissues. Though a number of renal tubule targeting mouse lines have been developed their utility for the study of renal disease is limited by lack of inducibility and specificity. In this study we describe the generation and characterisation of two novel mouse lines directing CreERT2 expression to renal tubular epithelia. The Pax8-CreERT2 transgenic line uses the mouse Pax8 promoter to direct expression of CreERT2 to all renal tubular compartments (proximal and distal tubules as well as collecting ducts) whilst the Slc22a6-CreERT2 knock-in line utilises the endogenous mouse Slc22a6 locus to specifically target the epithelium of proximal renal tubules. Both lines show high organ and tissue specificity with no extrarenal activity detected. To establish the utility of these lines for the study of renal cancer biology, Pax8-CreERT2 and Slc22a6-CreERT2 mice were crossed to conditional Vhl knockout mice to induce long-term renal tubule specific Vhl deletion. These models exhibited renal specific activation of the hypoxia inducible factor pathway (a VHL target). Our results establish Pax8-CreERT2 and Slc22a6-CreERT2 mice as valuable tools for the investigation and modelling of complex renal biology and disease.

Female adnexal tumors of probable Wolffian origin are rare and present a diagnostic challenge due to their morphological and immunohistochemical overlap with more common ovarian and broad ligament entities. We evaluated the morphological, immunohistochemical, and molecular features of 15 tumors of probable Wolffian origin. Patients ranged from 32 to 69 (mean 47) years and tumors from 1.8 to 30 (mean 10) cm. All except one arose in para-adnexal soft tissues. Follow-up was available for six patients, five of whom were alive and well, while the sixth, who had extra-adnexal disease at diagnosis, died from unrelated causes. The following patterns were noted: tubular (all tumors), solid 11/15 (73%), sieve-like 7/15 (47%), and reticular 1/15 (7%). A myxoid background was present in 3/15 (20%) of tumors and eosinophilic luminal secretions in 11/15 (73%). Most tumors (12/15, 80%) had low-grade nuclear atypia, while three showed foci with scattered high-grade atypia. Mitotic index ranged from 0 to 17 (mean 4) per ten high-power fields. Tumors were positive for pankeratin and negative for TTF-1. EMA, GATA3, and PAX8 were positive in 2/10 (20%; focal), 3/15 (20%; focal), and 1/15 (7%; focal) of tumors, respectively. CD10, SF-1, calretinin, inhibin, ER, PR, cytokeratin 7, and WT1 were variably expressed. Pathogenic mutations were rare and included STK11 (n = 3), APC (n = 1), and MBD4 (n = 1). Copy number variations were detected in the three tumors with STK11 mutations and a myxoid background. These data demonstrate that female adnexal tumors of probable Wolffian origin are morphologically and immunohistochemically diverse, but infrequently harbor pathogenic mutations. However, their lack of mutations in contrast to their mimickers may be a valuable tool in diagnostically difficult cases.

OBJECTIVE

To report a clear cell renal cell carcinoma recipient of a metastasizing ductal carcinoma of the breast: A tumor-to-tumor metastasis.

METHODS

A 71 year-old woman with a past history of breast carcinoma, diagnosed 12 years before, underwent a nephrectomy for an incidental kidney mass found in a routine imaging examination.

RESULTS

Histological examination revealed foci of ductal carcinoma of the breast in an otherwise typical clear cell renal cell carcinoma of the kidney. Immunohistochemical examination confirmed a metastasis of an infiltrating breast carcinoma to a clear cell renal cell carcinoma (positive to GATA3, hormonal receptors and mamoglobin) in a clear cell renal cell carcinoma (positive to PAX8, CD10 and vimentin).

CONCLUSIONS

Awareness of this phenomenon should always be kept in mind by urologist in patients with a known history of a previous malignancy and by pathologists when finding a renal tumor with an unusual or dimorphic morphology. Immunohistochemistry plays an important role to establish the exact diagnosis.

Pax genes encode developmental regulators that are expressed in a variety of tissues and control critical events in morphogenesis. In the kidney, Pax2 and Pax8 are expressed in embryonic development and in specific renal diseases associated with aberrant epithelial cell proliferation. Prior genetic and cell biological studies suggest that reducing the activity of Pax proteins in renal cancer or in polycystic kidney disease can slow the progression of these conditions. The Pax proteins may be critical for providing tissue and locus specificity to recruit epigenetic modifiers that control gene expression and chromatin structure. Although they are nuclear, targeting Pax proteins to inhibit function may be feasible with small molecules. Such inhibition of Pax protein function may provide novel therapies for subsets of renal disorders that are tissue- and cell type-specific and avoid systemic effects on non-Pax-expressing cells and tissues. Given the paucity of effective treatments for renal cancer and cystic disease, the Pax family of proteins represents new pharmaceutical targets that merit exploration and further development.

We present the clinicopathologic features of 15 cases of extragonadal yolk sac tumor (EGYST) detected in female patients and reviewed at our institution from 1988 to 2016. We recorded: patient age, clinical presentation, tumor location, FIGO stage (where applicable), histologic patterns including presence/absence of Schiller-Duval bodies, other germ cell or somatic components, immunoperoxidase results, treatment, and outcome. Patients' ages ranged from 17 to 87 (median, 62) years and presentation included: abnormal uterine bleeding, 12; hematuria, 1; labial mass, 1; abdominal pain, 1. Primary sites were as follows: uterus (11), vagina (1), vulva (1), bladder (1), and peritoneum (1). Seven patients presented at FIGO stage III or IV. The following histologic patterns were observed: microcystic/reticular (7), glandular (8), solid (8), papillary (5), and hepatoid (1). An admixture of histologic patterns was present in 10 cases. Schiller-Duval bodies were seen in only 3 (23%) cases. Eight cases (46%), all uterine primaries, had associated somatic components, and 2 (15%) had a second germ cell component. In 13/14 (93%) cases, the yolk sac tumor component was either missed or misclassified as adenocarcinoma. Immunoperoxidase studies facilitated the diagnosis in all cases as follows: SALL4, 12/12; CDX2, 10/12; α fetoprotein, 7/14; glypican-3, 9/10; cytokeratin 20, 5/9 (rare cells); cytokeratin 7, 3/12 (nondiffuse); PAX8, 2/9 (variable expression). All patients received chemotherapy and all except 1 underwent surgical resection. Follow-up from 5 to 86 months was available for 13 patients: 5 died of disease, 6 are alive with disease, and 2 have no evidence of disease. EGYST arising in the female pelvis of peri/postmenopausal patients may be associated with a somatic component and represent either somatically derived YST or YST differentiation within a somatic carcinoma. EGYST in younger patients is likely a true germ cell neoplasm, and may respond to germ cell appropriate chemotherapy. The benefit of germ cell appropriate chemotherapy in somatically derived EGYST is less clear. Awareness that the presence of glandular or microcystic patterns may lead to under-recognition or misdiagnosis of EGYST in combination with immunomarkers for germ cell and yolk sac differentiation will facilitate the diagnosis.

The cell of origin of ovarian low-grade serous carcinoma (LGSC) remains unclarified. Our recent morphologic and immunophenotypic study suggests that most LGSCs may be derived from the fallopian tube. The purpose of the current study was to gain further insight into the origin of LGSC at the molecular level.

RNA-seq analysis was performed on a total of 31 tissue samples including LGSC (n=6), serous borderline tumors (SBT, n=6), fallopian tube epithelia (FTE, n=5), ovarian surface epithelia (OSE, n=4), and human peritoneal mesothelia (HPM, n=4). HGSC cases (n=6) served as a positive control. Gene expression profiles were compared and analyzed. To validate the findings from the gene expression array study, we selected the highly differentially expressed genes (PAX8, CDH1, FOXA2, and ARX) as well as those corresponding proteins and examined their expression levels in tissue samples of ovarian serous tumors, fallopian tube, ovarian surface epithelia, and peritoneal mesothelia.

Dendrograms revealed that OSE samples clustered with HPM, while ovarian serous tumors, including LGSC, SBT and high-grade serous carcinoma (HGSC), clustered with FTE. Furthermore, LGSC showed a significantly closer relationship with FTE than with OSE and HPM samples. PAX8, CDH1, and FOXA2 were highly and specifically expressed in serous tumors and FTE samples but not in OSE samples. In contrast, ARX was mainly expressed in OSE samples but not in FTE and serous tumors.

The findings of the current study provide further evidence at a molecular level that the fallopian tube is likely the cellular source of LGSC. This finding may enable new prevention strategies, improve early detection, and allow novel therapies to be tested.

The functional consequences of somatic non-coding mutations in ovarian cancer (OC) are unknown. To identify regulatory elements (RE) and genes perturbed by acquired non-coding variants, here we establish epigenomic and transcriptomic landscapes of primary OCs using H3K27ac ChIP-seq and RNA-seq, and then integrate these with whole genome sequencing data from 232 OCs. We identify 25 frequently mutated regulatory elements, including an enhancer at 6p22.1 which associates with differential expression of ZSCAN16 (P = 6.6 × 10-4) and ZSCAN12 (P = 0.02). CRISPR/Cas9 knockout of this enhancer induces downregulation of both genes. Globally, there is an enrichment of single nucleotide variants in active binding sites for TEAD4 (P = 6 × 10-11) and its binding partner PAX8 (P = 2×10-10), a known lineage-specific transcription factor in OC. In addition, the collection of cis REs associated with PAX8 comprise the most frequently mutated set of enhancers in OC (P = 0.003). These data indicate that non-coding somatic mutations disrupt the PAX8 transcriptional network during OC development.

Primary congenital hypothyroidism (CH) is the most common endocrine disease in children and one of the most common preventable causes of both cognitive and motor deficits. CH is a heterogeneous group of thyroid disorders in which inadequate production of thyroid hormone occurs due to defects in proteins involved in the gland organogenesis (dysembryogenesis) or in multiple steps of thyroid hormone biosynthesis (dyshormonogenesis). Dysembryogenesis is associated with genes responsible for the development or growth of thyroid cells: such as NKX2-1, FOXE1, PAX8, NKX2-5, TSHR, TBX1, CDCA8, HOXD3 and HOXB3 resulting in agenesis, hypoplasia or ectopia of thyroid gland. Nevertheless, the etiology of the dysembryogenesis remains unknown for most cases. In contrast, the majority of patients with dyshormonogenesis has been linked to mutations in the SLC5A5, SLC26A4, SLC26A7, TPO, DUOX1, DUOX2, DUOXA1, DUOXA2, IYD or TG genes, which usually originate goiter. About 800 genetic mutations have been reported to cause CH in patients so far, including missense, nonsense, in-frame deletion and splice-site variations. Many of these mutations are implicated in specific domains, cysteine residues or glycosylation sites, affecting the maturation of nascent proteins that go through the secretory pathway. Consequently, misfolded proteins are permanently entrapped in the endoplasmic reticulum (ER) and are translocated to the cytosol for proteasomal degradation by the ER-associated degradation (ERAD) machinery. Despite of all these remarkable advances in the field of the CH pathogenesis, several points on the development of this disease remain to be elucidated. The continuous study of thyroid gene mutations with the application of new technologies will be useful for the understanding of the intrinsic mechanisms related to CH. In this review we summarize the present status of knowledge on the disorders in the protein folding caused by thyroid genes mutations.

Cancer of unknown primary (CUP) is a malignant widespread metastatic disease without an identifiable primary site after extensive clinical investigation. Recently, a decline is observed in the diagnosis of CUP, mainly due to improvement in detection of the primary tumors, thus decreasing the unknown primaries. Worldwide, CUP is the sixth to eighth most common malignancy, accounting for 2.3% to 5% of a new cancer diagnosis. CUP is third to fourth most common cause of death due to cancer-related mortality. The prognosis of CUP is depressing with the median survival of three to six months in the previous studies, but according to recent studies, median survival is less than one year. High risk for developing CUP is seen in heavy smokers (26 or more cigarettes/day) and individuals with the lowest quartiles of waist circumference. A weak association is observed with the use of alcohol consumption and low level of education. Human papillomavirus DNA plays a role in those with squamous cell carcinoma of unknown primaries in head and neck regions. In the diagnosis of CUP, comprehensive medical history, complete physical examination (including genitourinary, rectal exam, and breast examination in women) and necessary laboratory tests are crucial. Whole-body positron emission tomography-computed tomography (PET/CT) is the investigation of choice to assess the entire body for CUP. Multiparametric 3T-MRI (MP-MRI) is used to examine the local soft tissue status, helps in the staging of the tumor, and to determine the extent of involvement of tissue for medical as well as prognostic purposes. Immunohistochemistry outlines the specific markers, including caudal-related homeobox protein (CDX2), homeobox protein Nkx-3.1 (NKX3-1), paired box gene 8 (PAX8), special AT-rich sequence-binding protein 2 (SATB2), thyroid transcription factor 1 (TTF-1), and splicing factor 1 (SF1) with the focus on the effectiveness of lineage-restricted transcription factors. Patients response to treatment can be evaluated by the gene expression profiling (GEP) test that also predicts tissue of origin (TOO). Tumor identified through gene profiling is sensitive to platinum/taxane therapy, others that are not TOO tumors are resistant to platinum/taxane. The new therapeutic method based on molecular profiling is associated with higher treatment response. In comprehensive genomic profiling, it is observed that there is at least one clinically appropriate genomic alteration in CUP that can influence the targeted therapy. The targeted therapeutic approach will not only improve the disease outcome but will also be cost-effective and save time from finding the primary site.

Several subtypes of high-grade endometrial carcinomas (ECs) contain an undifferentiated component of non-epithelial morphology, including undifferentiated and dedifferentiated carcinomas and carcinosarcomas (CSs). The mechanism by which an EC undergoes dedifferentiation has been the subject of much debate. The epithelial-mesenchymal transition (EMT) is one of the mechanisms implicated in the transdifferentiation of high-grade carcinomas. To improve our understanding of the role of EMT in these tumors, we studied a series of 89 carcinomas including 14 undifferentiated/dedifferentiated endometrial carcinomas (UECs/DECs), 49 CSs (21 endometrial, 29 tubo-ovarian and peritoneal), 17 endometrioid carcinomas (grade 1-3), and 9 high-grade serous carcinomas of the uterus, using a panel of antibodies targeting known epithelial markers (Pan-Keratin AE1/AE3 and E-cadherin), mesenchymal markers (N-cadherin), EMT transcription factors (TFs) (ZEB1, ZEB2, TWIST1), PAX8, estrogen receptors (ER), progesterone receptors (PR), and the p53 protein. At least one of the three EMT markers (more frequently ZEB1) was positive in the sarcomatous component of 98% (n = 48/49) of CSs and 98% (n = 13/14) of the undifferentiated component of UEC/DEC. In addition, 86% of sarcomatous areas of CSs and 79% of the undifferentiated component of UEC/DEC expressed all three EMT-TFs. The expression of these markers was associated with the loss of or reduction in epithelial markers (Pan-keratin, E-cadherin), PAX8, and hormone receptors. In contrast, none of the endometrioid and serous endometrial carcinomas expressed ZEB1, while 6% and 36% of endometrioid and 11% and 25% of serous carcinomas focally expressed ZEB2 and TWIST1, respectively. Although morphologically different, EMT appears to be implicated in the dedifferentiation in both CSs and UEC/DEC. Indeed, we speculate that the occurrence of EMT in a well differentiated endometrioid carcinoma may consecutively lead to a dedifferentiated and undifferentiated carcinoma, while in a type II carcinoma, it may result in a CS.