TP53 mutations and survival in ovarian carcinoma patients receiving first-line chemotherapy plus bevacizumab: Results of the MITO16A/MaNGO OV-2 study.

To date, there are no biomarkers that define a patient subpopulation responsive to bevacizumab (BEV), an effective treatment option for advanced ovarian carcinoma (OC). In the context of the MITO16A/MaNGO OV-2 trial, a Phase IV study of chemotherapy combined with BEV in first-line treatment of advanced OC, we evaluated TP53 mutations by next-generation sequencing and p53 expression by immunohistochemistry (IHC) on 202 and 311 cases, respectively. We further correlated TP53 mutations in terms of type, function, and site, and IHC data with patients' clinicopathological characteristics and survival. TP53 missense mutations of unknown function (named unclassified) represented the majority of variants in our population (44.4%) and were associated with a significantly improved overall survival (OS) both in univariable (hazard ratio [HR] = 0.43, 95% confidence interval [CI] = 0.20-0.92, p = .03) and multivariable analysis (HR = 0.39, 95% CI = 0.18-0.86, p = .02). Concordance between TP53 mutational analysis and IHC was 91%. We observed an HR of 0.70 for OS in patients with p53 IHC overexpression compared to p53 wild-type, which however did not reach statistical significance (p = .31, 95% CI = 0.36-1.38). Our results indicate that the presence of unclassified TP53 mutations has favorable prognostic significance in patients with OC receiving upfront BEV plus chemotherapy. In particular, unclassified missense TP53 mutations characterize a subpopulation of patients with a significant survival advantage, independently of clinicopathological characteristics. Our findings warrant future investigations to confirm the prognostic impact of TP53 mutations in BEV-treated OC patients and deserve to be assessed for their potential predictive role in future randomized clinical studies.

Cerebellar phenotypes in germline PTEN mutation carriers.

PTEN hamartoma tumour syndrome (PHTS) comprises different hereditary conditions caused by germline PTEN mutations, predisposing to the development of multiple hamartomas in many body tissues and also increasing the risk of some types of cancer. Cerebellar involvement in PHTS patients has been long known due to the development of a pathognomonic cerebellar hamartoma (known as dysplastic gangliocytoma of the cerebellum or Lhermitte-Duclos disease). Recently, a crucial role of the cerebellum has been highlighted in the pathogenesis of autism spectrum disorders, now recognised as a phenotype expressed in a variable percentage of PHTS children. In addition, rare PTEN variants are indeed identified in medulloblastoma as well, even if they are less frequent than other germline gene mutations. The importance of PTEN and its downstream signalling enzymatic pathways, PI3K/AKT/mTOR, has been studied at different levels in both human clinical settings and animal models, not only leading to a better understanding of the pathogenesis of different disorders but, most importantly, to identify potential targets for specific therapies. In particular, PTEN integrity makes an important contribution to the normal development of tissue architecture in the nervous system, including the cerebellum. Thus, in patients with PTEN germline mutations, the cerebellum is an affected organ that is increasingly recognised in different disorders, whereas, in animal models, cerebellar Pten loss causes a variety of functional and histological alterations. In this review, we summarise the range of cerebellar involvement observed in PHTS and its relationships with germline PTEN mutations, along with the phenotypes expressed by murine models with PTEN deficiency in cerebellar tissue.

Predicting tumor consistency and extent of resection in non-functioning pituitary tumors.

PURPOSE: To (1) identify a radiological parameter to predict non-functioning pituitary tumor (NFPT) consistency, (2) examine the relationship between NFPT consistency and extent of resection (EOR), (3) investigate if tumor consistency predictors can anticipate EOR. METHODS: The ratio (T2SIR) between the T2 min signal intensity (SI) of the tumor and the T2 mean SI of the CSF was the main radiological parameter, being determined through a radiomic-voxel analysis and calculated using the following formula: T2SIR = [(T2 tumor mean SI - SD)/T2 CSF SI]. The tumor consistency was pathologically estimated as collagen percentage (CP). EOR of NFPTs was evaluated by exploiting a volumetric technique and its relationship with the following explanatory variables was explored: CP, Knosp-grade, tumor volume, inter-carotid distance, sphenoidal sinus morphology, Hardy-grade, suprasellar tumor extension. RESULTS: A statistically significant inverse correlation between T2SIR and CP was demonstrated (p = 0.0001), with high diagnostic power of T2SIR in predicting NFPT consistency (ROC curve analysis' AUC = 0.88; p = 0.0001). The following predictors of EOR were identified in the univariate analysis: CP (p = 0.007), preoperative volume (p = 0.045), Knosp grade (p = 0.0001), tumor suprasellar extension (p = 0.044). The multivariate analysis demonstrated two variables as unique predictors of EOR: CP (p = 0.002) and Knosp grade (p = 0.001). The T2SIR was a significant predictor of EOR both in the univariate (p = 0.01) and multivariate model (p = 0.003). CONCLUSION: This study offers the potential to improve NFPT preoperative surgical planning and patient counseling by employing the T2SIR as a preoperative predictor of tumor consistency and EOR. Meanwhile, tumor consistency and Knosp grade were found to play an important role in predicting EOR.

Angiosarcoma and anaplastic carcinoma of the thyroid are two distinct entities: a morphologic, immunohistochemical, and genetic study.

Angiosarcoma and anaplastic carcinoma are the most lethal neoplasms of the thyroid worldwide and share some similarities, which have led to a longstanding controversy on their etiopathological relationship. Thyroid angiosarcomas are characterized by vessel formation and an immunophenotype common to endothelial cells, while anaplastic carcinomas are partially or wholly composed of mesenchymal-like cells that have lost the morphologic and functional features of normal thyroid follicular cells. To investigate whether angiosarcomas represent the endothelial extreme of the differentiation spectrum of carcinomas or they are bona fide vascular neoplasms, we studied the clinico-morphologic and genetic characteristics of a series of 10 angiosarcomas and 22 anaplastic carcinomas. Immunohistochemically, among the endothelial markers, CD31 and ERG were the most consistently expressed in angiosarcomas. Among the markers of thyroid origin, PAX8 was the most reliable in anaplastic carcinomas, while TTF-1 reactivity was found in only 5% of anaplastic carcinomas and thyroglobulin was always negative. Pankeratin reacted with most angiosarcomas and anaplastic carcinomas and is therefore not useful in the differential diagnosis. Interestingly a mutated pattern of p53 immunostaining prompted a diagnosis of anaplastic carcinoma. To compare the genetic profile, we used the NGS approach to sequence hotspot regions within a panel of 57 genes. As a result, only a few mutations were found in angiosarcomas and all of them were single events (no TP53 or TERT mutation). On the other hand, anaplastic carcinomas were characterized by a higher number of mutations, and TP53 and TERT promoter mutations were the most frequent genetic alterations. The lack in angiosarcomas of the common mutations identified in anaplastic carcinomas supports a different genetic origin and strongly suggests that, in spite of a shared sarcomatous morphology and a similar clinical aggressiveness, angiosarcomas and anaplastic carcinomas rely on a completely different set of genetic alterations during their evolution.

Steroid hormone synthesis by the ovarian stroma surrounding epithelial ovarian tumors: a potential mechanism in ovarian tumorigenesis.

Epithelial ovarian tumors are responsive to steroid hormone stimulation and the ovarian stroma may have a direct role in this process. We evaluated immunohistochemical markers of sex-steroid differentiation and steroidogenesis (calretinin, inhibin, steroidogenic factor 1), steroid enzymes involved in hormone biosynthesis (CYP17, CYP19, HSD17ß1, AKR1C3), and hormone receptors (estrogen receptor, progesterone receptor, and androgen receptor) in 101 epithelial ovarian tumors and in normal structures implicated in ovarian carcinogenesis (ovarian surface epithelium and cortical inclusion cysts) in an attempt to elucidate this process. We hypothesized that ovarian stroma immediately adjacent to tumors express markers of sex-steroid differentiation and steroidogenesis and steroid enzymes whereas the epithelium contains corresponding hormone receptors. As the findings in seromucinous, endometrioid, and clear cell neoplasms, tumors closely associated with endometriosis, were very similar, these were combined into a group designated 'endometriosis-related tumors.' Significantly increased expression of markers of sex-steroid differentiation and steroidogenesis was found in stroma immediately adjacent to endometriosis-related tumors (P=0.003) and mucinous tumors (primary and metastatic mucinous tumors were combined because of similar findings) (P<0.0001) compared with more remote ovarian stroma. In addition, sex-steroid enzymes were increased in stroma adjacent to endometriosis-related tumors (P=0.02) and mucinous tumors (P=0.02) compared with more distant stroma. Steroid hormone receptors showed greater expression in epithelium compared with stroma in the endometriosis-related tumors (P=0.0009), low-grade serous tumors (P<0.0001), and high-grade serous carcinoma (P=0.0036). In contrast, there was greater expression in stroma compared with epithelium (P<0.0001) in mucinous tumors, which may be due to the fact that they are not derived from müllerian epithelium. In conclusion, our findings strongly support the view that the stroma surrounding epithelial tumors in the ovary is activated to elaborate steroid hormones which may stimulate further neoplastic growth. The precise mechanisms by which this process might occur are complex and require further investigation.

CCNE1 copy-number gain and overexpression identify ovarian clear cell carcinoma with a poor prognosis.

Ovarian clear cell carcinoma is a unique type of ovarian cancer, often derived from endometriosis, and advanced-stage disease has a dismal prognosis primarily due to the resistance to conventional chemotherapy. Previous studies have shown frequent somatic mutations in ARID1A, PIK3CA, hTERT promoter, and amplification of ZNF217; however, the molecular alterations that are associated with its aggressiveness remain largely unknown. This study examined and compared cyclin E1 expression in endometriosis-related ovarian tumors, with the aim of determining the relationship between hTERT mutations and ARID1A expression and evaluating the effects of these molecular alterations on patient survival. We performed immunohistochemistry on 207 tumors [clear cell carcinoma (n=120), endometrioid carcinoma (n=49), and seromucinous tumors (n=38)], followed by two-color fluorescence in situ hybridization (n=88) and compared with ARID1A expression and hTERT promoter mutations in the same samples. Cyclin E1 overexpression and CCNE1 copy-number gain occurred in 23.3% and 14.8% of ovarian clear cell carcinomas, respectively, but they were not detected in any of the other endometriosis-related tumors. All cases with CCNE1 copy-number gain demonstrated an intense cyclin E1 immunoreactivity (P<0.001). Cyclin E1 overexpression was positively correlated with hTERT promoter mutations (P=0.01), but not with the loss of ARID1A expression. A multivariate analysis revealed that CCNE1 overexpression predicts poor overall survival, even after adjusting for stage and age. Specifically, CCNE1 overexpression and copy-number gain were both correlated with a poor outcome in patients with stage I disease. Moreover, the subset with CCNE1 overexpression and ARID1A retention demonstrated the worst outcome. Our findings suggest that gene copy-number gain and upregulation of CCNE1 occur in ovarian clear cell carcinoma and are associated with a worse clinical outcome, dictating the survival of early-stage patients, and that these molecular alterations are unique to clear cell carcinoma among different types of endometriosis-related ovarian neoplasms.

CCNE1 amplification and centrosome number abnormality in serous tubal intraepithelial carcinoma: further evidence supporting its role as a precursor of ovarian high-grade serous carcinoma.

Aberration in chromosomal structure characterizes almost all cancers and has profound biological significance in tumor development. It can be facilitated by various mechanisms including overexpression of cyclin E1 and centrosome amplification. As ovarian high-grade serous carcinoma has pronounced chromosomal instability, in this study we sought to determine whether increased copy number of CCNE1 which encodes cyclin E1 and centrosome amplification (>2 copies) occurs in its putative precursor, serous tubal intraepithelial carcinoma. We found CCNE1 copy number gain/amplification in 8 (22%) of 37 serous tubal intraepithelial carcinomas and 12 (28%) of 43 high-grade serous carcinomas. There was a correlation in CCNE1 copy number between serous tubal intraepithelial carcinoma and high-grade serous carcinoma in the same patients (P<0.001). There was no significant difference in the percentage of CCNE1 gain/amplification between serous tubal intraepithelial carcinoma and high-grade serous carcinoma (P=0.61). Centrosome amplification was recorded in only 5 (14%) of 37 serous tubal intraepithelial carcinomas, and in 10 (40%) of 25 high-grade serous carcinomas. The percentage of cells with centrosome amplification was higher in high-grade serous carcinoma than in serous tubal intraepithelial carcinoma (P<0.001). Induced expression of cyclin E1 increased the percentage of fallopian tube epithelial cells showing centrosome amplification. Our findings suggest that gain/amplification of CCNE1 copy number occurs early in tumor progression and precedes centrosome amplification. The more prevalent centrosome amplification in high-grade serous carcinoma than in serous tubal intraepithelial carcinoma supports the view that serous tubal intraepithelial carcinoma precedes the development of many high-grade serous carcinomas.

Endogenous androgens and risk of epithelial invasive ovarian cancer by tumor characteristics in the European Prospective Investigation into Cancer and Nutrition.

The role of endogenous androgens and sex hormone-binding globulin (SHBG) in ovarian carcinogenesis is poorly understood. Epithelial invasive ovarian cancer (EOC) is a heterogeneous disease and there are no prospective data on endogenous androgens and EOC risk by tumor characteristics (histology, grade, stage) or the dualistic model of ovarian carcinogenesis (i.e. type I vs. type II, leading to less or more aggressive tumors). We conducted a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort evaluating androgens and SHBG and invasive EOC risk by tumor characteristics. Female participants who provided a blood sample and were not using exogenous hormones at blood donation were eligible (n = 183,257). A total of 565 eligible women developed EOC; two controls (n = 1,097) were matched per case. We used multivariable conditional logistic regression models. We observed no association between androgens, SHBG and EOC overall. A doubling of androstenedione reduced risk of serous carcinomas by 21% (odds ratio (OR)log2 = 0.79, 95% confidence interval [CI] = [0.64-0.97]). Moreover, associations differed for low-grade and high-grade carcinomas, with positive associations for low-grade and inverse associations for high-grade carcinomas (e.g. androstenedione: low grade: ORlog2 = 1.99 [0.98-4.06]; high grade: ORlog2 = 0.75 [0.61-0.93], phet ≤ 0.01), similar associations were observed for type I/II tumors. This is the first prospective study to evaluate androgens, SHBG and EOC risk by tumor characteristics and type I/II status. Our findings support a possible role of androgens in ovarian carcinogenesis. Additional studies exploring this association are needed.

A genetically engineered ovarian cancer mouse model based on fallopian tube transformation mimics human high-grade serous carcinoma development.

Recent evidence suggests that ovarian high-grade serous carcinoma (HGSC) originates from the epithelium of the fallopian tube. However, most mouse models are based on the previous prevailing view that ovarian cancer develops from the transformation of the ovarian surface epithelium. Here, we report the extensive histological and molecular characterization of the mogp-TAg transgenic mouse, which expresses the SV40 large T-antigen (TAg) under the control of the mouse müllerian-specific Ovgp-1 promoter. Histological analysis of the fallopian tubes of mogp-TAg mice identified a variety of neoplastic lesions analogous to those described as precursors to ovarian HGSC. We identified areas of normal-appearing p53-positive epithelium that are similar to 'p53 signatures' in the human fallopian tube. More advanced proliferative lesions with nuclear atypia and epithelial stratification were also identified that were morphologically and immunohistochemically reminiscent of human serous tubal intraepithelial carcinoma (STIC), a potential precursor of ovarian HGSC. Beside these non-invasive precursor lesions, we also identified invasive adenocarcinoma in the ovaries of 56% of the mice. Microarray analysis revealed several genes differentially expressed between the fallopian tube of mogp-TAg and wild-type (WT) C57BL/6. One of these genes, Top2a, which encodes topoisomerase IIα, was shown by immunohistochemistry to be concurrently expressed with elevated p53 and was specifically elevated in mouse STICs but not in the surrounding tissues. TOP2A protein was also found elevated in human STICs, low-grade and high-grade serous carcinoma. The mouse model reported here displays a progression from normal tubal epithelium to invasive HGSC in the ovary, and therefore closely simulates the current emerging model of human ovarian HGSC pathogenesis. This mouse therefore has the potential to be a very useful new model for elucidating the mechanisms of serous ovarian tumourigenesis, as well as for developing novel approaches for the prevention, diagnosis and therapy of this disease.

Frequent CCNE1 amplification in endometrial intraepithelial carcinoma and uterine serous carcinoma.

Uterine serous carcinoma accounts for only 10% of all uterine epithelial cancers, but is the leading cause of death among them. The pathogenesis of this aggressive neoplasm has been largely elusive until recently, when comprehensive genome-wide analyses of uterine serous carcinoma have been performed. Among amplified cancer-related genes, CCNE1, encoding for cyclin E1, is frequently amplified in uterine serous carcinoma. In the current study we applied fluorescence in situ hybridization (FISH) to determine CCNE1 copy number in uterine serous carcinoma and concurrent endometrial intraepithelial carcinoma, the noninvasive component of uterine serous carcinoma, and the results were correlated with clinicopathological and molecular features. We found that 20 (45%) of 44 uterine serous carcinomas and 11 (41%) of 27 endometrial intraepithelial carcinomas showed CCNE1 amplification. Overall, we found high concordance in CCNE1 copy number in concurrent uterine serous carcinoma and endometrial intraepithelial carcinoma pairs (P-value=0.0003). No correlation was observed between CCNE1 copy number and clinicopathological features, as well as common mutations previously reported in uterine serous carcinoma. In summary, we confirm that amplification of CCNE1 is a frequent molecular genetic change in uterine serous carcinoma. Moreover, the identification of CCNE1 amplification in many endometrial intraepithelial carcinomas suggests that this genetic event occurs early during tumor progression.

The pathogenesis of atypical proliferative Brenner tumor: an immunohistochemical and molecular genetic analysis.

Brenner tumors are ovarian tumors, usually benign, containing epithelium that resembles transitional epithelium. As with other epithelial tumors there exist frankly malignant tumors and tumors that display greater proliferation than the benign Brenner tumors but lack destructive infiltrative growth, and these have been designated 'atypical proliferative' (borderline) Brenner tumors. There have been no well-documented cases of atypical proliferative Brenner tumors that have exhibited malignant behavior. Based on shared morphologic features it is generally believed that atypical proliferative Brenner tumors develop from benign Brenner tumors. The aim of the present study was to confirm this impression by investigating the immunohistochemical and molecular genetic features of benign and atypical proliferative Brenner tumors. Immunohistochemical staining for p16, fluorescence in-situ hybridization (FISH) for CDKN2A (p16-encoding gene) and mutational analysis of the genes commonly mutated in ovarian tumors were performed. p16 immunostaining was positive in the epithelial component of 12 (92%) of 13 benign Brenner tumors, but completely negative in all 7 atypical proliferative Brenner tumors. FISH identified homozygous deletion of CDKN2A in the epithelial component of all atypical proliferative Brenner tumors, but CDKN2A was retained in all benign Brenner tumors. Two PIK3CA somatic mutations were detected in the stromal component in 1 (5%) of 20 Brenner tumors and 3 somatic mutations (1 in KRAS and 2 in PIK3CA) were identified in the atypical epithelial component of 2 (29%) of 7 atypical proliferative Brenner tumors. In summary, our findings suggest that loss of CDKN2A and, to a lesser extent, KRAS and PIK3CA somatic mutations have a role in the progression of a benign to an atypical proliferative Brenner tumor.

Elevated PDGFRB gene copy number gain is prognostic for improved survival outcomes in resected malignant pleural mesothelioma.

PDGF/PDGFR pathway has been implicated in malignant pleural mesothelioma (MPM) carcinogenesis, and evidence suggests autocrine mechanisms of proliferation. We sought to evaluate the incidence of PDGFRB gene copy number gain (CNG) by fluorescence in situ hybridization and PDGFR pathway protein expression by immunohistochemistry (IHC) and correlate it to patient clinical outcome. Eighty-eight archived tumor blocks from resected MPM with full clinical information were used to perform IHC biomarkers (PDGFRα, PDGFRß, p-PDGFRß) and fluorescence in situ hybridization analysis of PDGFRB gene CNG. Spearman rank correlation, Wilcoxon rank-sum test, Kruskal-Wallis test, BLiP plots, and Kaplan-Meier method were used to analyze the biomarkers and correlation to clinical outcome. Several correlations between the IHC biomarkers were seen; however, none correlated to clinically relevant patient demographics or histology. In the CNG analysis, PDGFRB gene CNG in >10% of tumor cells had lower cytoplasmic p-PDGFRß (P=.029), while PDGFRB gene CNG in >40% of tumor cells had a higher cytoplasmic PDGFRß (P=.04). PDGFRB gene CNG status did not associate with patient demographics or tumor characteristics. PDGFR pathway IHC biomarkers did not associate with survival outcomes. However, patients with PDGFRB CNG >40% of tumor cells had improved relapse-free survival (HR 0.25 [95% CI 0.09-0.72], P=.0096) and improved overall survival (HR 0.32 [95% CI 0.11-0.89], P=.029). PDGFRB CNG >40% of MPM tumor cells is a potential prognostic biomarker for surgery and may identify a unique population of mesothelioma patients. Future validation of this biomarker in prospective trials is needed. From a retrospective review of archived tissue specimens from patients with resected malignant pleural mesothelioma tumors, we show that patients with PDGFRB CNG >40% of tumor cells had improved relapse-free survival (HR 0.25 [95% CI 0.09-0.72], P=.0096) and improved overall survival (HR 0.32 [95% CI 0.11-0.89], P=.029). PDGFRB CNG >40% of MPM tumor cells is a potential prognostic biomarker for surgery and may identify a unique population of mesothelioma patients.

Unsolved Issues in the Integrated Histo-Molecular Classification of Endometrial Carcinoma and Therapeutic Implications.

Endometrial carcinoma (EC) is the most frequent gynecological cancer, with an increasing incidence and mortality in recent times. The last decade has represented a true revolution with the development of the integrated histo-molecular classification of EC, which allows for the stratification of patients with morphologically indistinguishable disease into groups with different prognoses. Particularly, the POLE-mutated subgroup exhibits outstanding survival. Nevertheless, the indiscriminate application of molecular classification appears premature. Its prognostic significance has been proven mainly in endometrioid EC, the most common histotype, but it has yet to be convincingly confirmed in the other minor histotypes, which indeed account for a relevant proportion of EC mortality. Moreover, its daily use both requires a mindful pathologist who is able to correctly evaluate and unambiguously report immunohistochemical staining used as a surrogated diagnostic tool and is hampered by the unavailability of POLE mutation analysis. Further molecular characterization of ECs is needed to allow for the identification of better-tailored therapies in different settings, as well as the safe avoidance of surgery for fertility preservation. Hopefully, the numerous ongoing clinical trials in the adjuvant and metastatic settings of EC will likely produce evidence to refine the histo-molecular classification and therapeutic guidelines. Our review aims to retrace the origin and evolution of the molecular classification for EC, reveal its strengths and limitations, show clinical relevance, and uncover the desired future developments.

Unlocking the potential of Molecular Tumor Boards: from cutting-edge data interpretation to innovative clinical pathways.

The emerging era of precision medicine is characterized by an increasing availability of targeted anticancer therapies and by the parallel development of techniques to obtain more refined molecular data, whose interpretation may not always be straightforward. Molecular tumor boards gather various professional figures, in order to leverage the analysis of molecular data and provide prognostic and predictive insights for clinicians. In addition to healthcare development, they could also become a tool to promote knowledge and research spreading. A growing body of evidence on the application of molecular tumor boards to clinical practice is forming and positive signals are emerging, although a certain degree of heterogeneity exists. This work analyzes molecular tumor boards' potential workflows, figures involved, data sources, sample matrices and eligible patients, as well as available evidence and learning examples. The emerging concept of multi-institutional, disease-specific molecular tumor boards is also considered by presenting two ongoing nationwide experiences.

Colorectal carcinoma peritoneal metastases-derived organoids: results and perspective of a model for tailoring hyperthermic intraperitoneal chemotherapy from bench-to-bedside.

BACKGROUND: Peritoneal metastases from colorectal cancer (CRCPM) are related to poor prognosis. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been reported to improve survival, but peritoneal recurrence rates are still high and there is no consensus on the drug of choice for HIPEC. The aim of this study was to use patient derived organoids (PDO) to build a relevant CRCPM model to improve HIPEC efficacy in a comprehensive bench-to-bedside strategy. METHODS: Oxaliplatin (L-OHP), cisplatin (CDDP), mitomycin-c (MMC) and doxorubicin (DOX) were used to mimic HIPEC on twelve PDO lines derived from twelve CRCPM patients, using clinically relevant concentrations. After chemotherapeutic interventions, cell viability was assessed with a luminescent assay, and the obtained dose-response curves were used to determine the half-maximal inhibitory concentrations. Also, induction of apoptosis by different HIPEC interventions on PDOs was studied by evaluating CASPASE3 cleavage. RESULTS: Response to drug treatments varied considerably among PDOs. The two schemes with better response at clinically relevant concentrations included MMC alone or combined with CDDP. L-OHP showed relative efficacy only when administered at low concentrations over a long perfusion period. PDOs showed that the short course/high dose L-OHP scheme did not appear to be an effective choice for HIPEC in CRCPM. HIPEC administered under hyperthermia conditions enhanced the effect of chemotherapy drugs against cancer cells, affecting PDO viability and apoptosis. Finally, PDO co-cultured with cancer-associated fibroblast impacted HIPEC treatments by increasing PDO viability and reducing CASPASES activity. CONCLUSIONS: Our study suggests that PDOs could be a reliable in vitro model to evaluate HIPEC schemes at individual-patient level and to develop more effective treatment strategies for CRCPM.

Clinically occult tubal and ovarian high-grade serous carcinomas presenting in uterine samples: diagnostic pitfalls and clues to improve recognition of tumor origin.

We report the clinicopathologic and immunohistochemical features in 8 patients with tubal or ovarian high-grade serous carcinoma that was present in uterine samples, in which there was the potential for clinical and morphologic misinterpretation as a primary uterine lesion before hysterectomy/bilateral salpingo-oophorectomy. Patients ranged in age from 45 to 70 yr (mean, 57 yr). The initial presentation was variable, ranging from incidental findings on routine Pap smears to pleural effusion. During the preoperative clinical investigation, 7 of 8 patients did not have evidence of an adnexal tumor based on physical examination and radiologic imaging, and serum CA-125 levels were normal to low in 4 of 5 patients. Six patients required multiple rounds of uterine samples, and the preoperative uterine specimens that contained lesional tissue and were available for rereview in all 8 patients included endometrial biopsies/curettages (n=6), endocervical curettages (n=3), Pap smears (n=2), and a hysteroscopic myomectomy specimen (n=1). The amount of carcinoma in these specimens was typically scanty. The lesions in most cases were characterized by detached and minute epithelial clusters, small papillae, and/or individual cells. The constituent glandular cells exhibited notable atypia. Psammoma bodies were identified in only 2 cases. Immunostains for WT-1 were positive in 3 of 4 preoperative specimens. All patients ultimately underwent a hysterectomy/bilateral salpingo-oophorectomy, which revealed an invasive high-grade serous carcinoma of tubal (n=6) or ovarian (n=2) origin. The mean/median tumor size was 3.2/1.7 cm. Transtubal spread was considered the most likely mechanism resulting in tubal/ovarian carcinoma being found in the preoperative uterine samples. These findings highlight the deceptive clinical features of some tubal/ovarian high-grade serous carcinomas, and demonstrate that small and clinically undetectable adnexal high-grade serous carcinomas can initially present in uterine biopsies/curettages. To guide clinical evaluation more accurately and prevent histologic misdiagnosis/misclassification, a possible adnexal origin should be considered in the differential diagnosis of small, detached, and markedly atypical glandular fragments in endometrial or cervical specimens, and immunohistochemical staining for WT-1 is recommended in this setting.

TP53 mutations in serous tubal intraepithelial carcinoma and concurrent pelvic high-grade serous carcinoma--evidence supporting the clonal relationship of the two lesions.

Serous tubal intraepithelial carcinomas (STICs) have been proposed to be the most likely precursor of ovarian, tubal and 'primary peritoneal' (pelvic) high-grade serous carcinoma (HGSC). As somatic mutation of TP53 is the most common molecular genetic change of ovarian HGSC, occurring in more than 95% of cases, we undertook a mutational analysis of 29 pelvic HGSCs that had concurrent STICs to demonstrate the clonal relationship of STICs and HGSCs. In addition, we correlated the mutational data with p53 immunostaining to determine the role of p53 immunoreactivity as a surrogate for TP53 mutations in histological diagnosis. Somatic TP53 mutations were detected in all 29 HGSCs analysed and the identical mutations were detected in 27 of 29 pairs of STICs and concurrent HGSCs. Missense mutations were observed in 61% of STICs and frameshift/splicing junction/nonsense mutations in 39%. Interestingly, there were two HGSCs with two distinctly different TP53 mutations each, but only one of the mutations was detected in the concurrent STICs. Missense mutations were associated with intense and diffuse (≥ 60%) p53 nuclear immunoreactivity, while most of the null mutations were associated with complete loss of p53 staining (p < 0.0001). Overall, this p53 staining pattern yielded a sensitivity of 87% and a specificity of 100% in detecting TP53 missense mutations. In conclusion, the above findings support the clonal relationship of STIC and pelvic HGSC and demonstrate the utility of p53 immunostaining as a surrogate for TP53 mutation in the histological diagnosis of STIC. In this regard, it is important to appreciate the significance of different staining patterns. Specifically, strong diffuse staining correlates with a missense mutation, whereas complete absence of staining correlates with null mutations.

Paratesticular Extramedullary Hematopoiesis in Children.

CONTEXT.­: Extramedullary hematopoiesis (EMH) is an uncommon occurrence, usually associated with hematologic disorders, but it rarely presents as an isolated finding. OBJECTIVE.­: To determine the frequency, immunomorphologic features, and clinicopathologic background of EMH in orchiectomies from pediatric patients. DESIGN.­: All orchiectomy specimens removed from children from 2008 to 2020 in our institution were retrospectively reviewed. Biopsies and neoplasias were excluded. The EMH diagnosis was rendered when hematopoietic cell precursors were present. Immunohistochemical stainings were performed to characterize the hematopoietic components. RESULTS.­: Seventy-nine orchiectomies from 77 children (mean age, 5 years; range, 0-17 years) were included in our study. Forty-three patients (55.8%) underwent surgery for testicular atrophy, 30 (39.0%) for torsion, and 4 (5.2%) for intersex conditions. EMH was identified in 6 of 79 orchiectomies (7.6%), all performed for testicular torsion. All patients but one were newborns, and the remaining patient was 15 years old. No patient had evidence of a hematologic disorder. All EMH foci were in a background of reactive changes with a variable extension, either in the epididymis (4 cases) or in the deferens duct (2 cases). Immunostaining confirmed an association of myeloid (myeloperoxidase+) and erythroid precursors (E-cadherin+) in all 6 cases. One case also presented rare megakaryocytes, and one showed benign TdT+ B-cell precursors. CONCLUSIONS.­: To our knowledge, this is the first study that demonstrates EMH as a common finding in orchiectomy samples, especially from newborns. Despite the lack of pathologic potential, it is important to recognize EMH in order to avoid misdiagnosis.

Thymic Epithelial Tumors: An Evolving Field.

Despite their rarity, thymic epithelial tumors (TETs) have attracted much interest over the years, leading to an impressive number of histological and staging classifications. At present, TETs are divided by the WHO classification into four main subtypes: type A, type AB, and type B thymomas (subdivided into B1, B2, and B3), and thymic carcinomas, going from the more indolent to the most aggressive ones. Among many debated staging proposals, the TNM and the Masaoka-Koga staging systems have been widely accepted and used in routine practice. The four-tiered histological classification is symmetrically mirrored by the molecular subgrouping of TETs, which identifies an A-like and an AB-like cluster, with frequent GTF2I and HRAS mutations; an intermediate B-like cluster, with a T-cell signaling profile; and a carcinoma-like cluster comprising thymic carcinomas with frequent CDKN2A and TP53 alterations and a high tumor molecular burden. Molecular investigations have opened the way to tailored therapies, such as tyrosine kinase inhibitors targeting KIT, mTOR, and VEGFR, and immune-checkpoints that have been adopted as second-line systemic treatments. In this review, we discuss the crucial events that led to the current understanding of TETs, while disclosing the next steps in this intriguing field.