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Aims: Benign tumours of the rete testis include mostly cystadenomas and adenomas. A subset with tubular or tubulopapillary architecture shows morphological similarities to Sertoli cell tumours; these neoplasms were previously termed "Sertoliform cystadenomas of the rete testis". In the most recent WHO classification, they have been interpreted as Sertoli cell tumours, not otherwise specified (NOS), with pure intra-rete growth, and therefore excluded as an entity. The remaining cystadenomas of the rete testis vaguely resemble tumours of Mullerian origin arising in the ovaries. In this study we analyse benign tumours of the rete testis, including a subset with Sertoliform features., Methods and Results: Benign neoplasms of the rete testis were identified through query of consultation and institutional files. Clinicopathologic data were collected, and available slides were reviewed. Cases were assessed using IHC and three separate DNA sequencing panels. Eleven tumours from patients 32-78 years old were evaluated. Four were classified as Sertoliform adenomas/cystadenomas, displaying tubulo-papillary or tubular/trabecular architecture; all of them were PAX8-positive and lacked nuclear beta-catenin expression. The remaining seven tumours were benign cystadenomas NOS. Genomic analysis was performed successfully in 10/11 tumours (including all Sertoliform adenomas/cystadenomas) and revealed no pathogenic variants in CTNNB1, KRAS, or BRAF., Conclusion: Sertoliform cystadenomas of the rete testis differ from Sertoli cell tumours NOS, as evidenced by the absence of molecular markers characteristic of Sertoli cell tumours. The remaining benign cystadenomas lack molecular alterations seen in Mullerian tumors of the ovaries., (© 2025 The Author(s). Histopathology published by John Wiley & Sons Ltd.)

Juxtaglomerular cell tumor (JxGCT) is a rare type of renal neoplasm demonstrating morphologic overlap with some mesenchymal tumors such as glomus tumor (GT) and solitary fibrous tumor (SFT). Its oncogenic drivers remain elusive, and only a few cases have been analyzed with modern molecular techniques. In prior studies, loss of chromosomes 9 and 11 appeared to be recurrent. Recently, whole-genome analysis identified alterations involving genes of MAPK-RAS pathway in a subset, but no major pathogenic alterations have been discovered in prior whole transcriptome analyses. Considering the limited understanding of the molecular features of JxGCTs, we sought to assess a collaborative series with a multiomic approach to further define the molecular characteristics of this entity. Fifteen tumors morphologically compatible with JxGCTs were evaluated using immunohistochemistry for renin, single-nucleotide polymorphism array (SNP), low-pass whole-genome sequencing, and RNA sequencing (fusion assay). In addition, methylation analysis comparing JxGCT, GT, and SFT was performed. All cases tested with renin (n=11) showed positive staining. Multiple chromosomal abnormalities were identified in all cases analyzed (n=8), with gains of chromosomes 1p, 10, 17, and 19 and losses of chromosomes 9, 11, and 21 being recurrent. A pathogenic HRAS mutation was identified in one case as part of the SNP array analysis. Thirteen tumors were analyzed by RNA sequencing, with 2 revealing in-frame gene fusions: TFG::GPR128 (interpreted as stochastic) and NAB2::STAT6. The latter, originally diagnosed as JxGCT, was reclassified as SFT and excluded from the series. No fusions were detected in the remaining 11 cases; of note, no case harbored NOTCH fusions previously described in GT. Genomic methylation analysis showed that JxGCT, GT, and SFT form separate clusters, confirming that JxGCT represents a distinct entity (ie, different from GT). The results of our study show that JxGCTs are a distinct tumor type with a recurrent pattern of chromosomal imbalances that may play a role in oncogenesis, with MAPK-RAS pathway activation being likely a driver in a relatively small subset., Competing Interests: Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with or financial interest in any commercial companies pertaining to this article., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Molecular classification of endometrial carcinomas (EC) divides these neoplasms into four distinct subgroups based on their molecular background. Given its clinical significance, genetic examination is becoming integral to the diagnostic process. This study aims to share our experience with the molecular classification of EC using immunohistochemistry (IHC) and next-generation sequencing (NGS). We included all ECs diagnosed at two institutions from 2020 to the present. All cases were prospectively examined by IHC for MMR proteins and p53, followed by NGS using a customized panel covering 18 genes, based on which ECs were classified into four molecular subgroups: POLE mutated, hypermutated (MMR deficient), no specific molecular profile (NSMP), and TP53 mutated. The cohort comprised 270 molecularly classified ECs: 18 (6.6%) POLE mutated, 85 (31.5%) hypermutated, 137 (50.7%) NSMP, and 30 (11.1%) TP53 mutated. Twelve cases (4.4%) were classified as 'multiple classifier' EC. Notably, most of these cases with available follow-up (6/9) behaved aggressively. Within the POLEmut EC group, 3/4 cases had advanced tumors, including one patient who died of the disease. Similarly, in the MMRd/TP53mut group, 3/5 patients with available follow-up had metastatic disease, leading to death of the patient in 1 case. ECs of NSMP showed multiple genetic alterations, with the most common mutations being PTEN (44% within the group of NSMP), followed by PIK3CA (30%), ARID1A (21%), and KRAS (9%). Our findings suggest that combining immunohistochemistry with NGS offers a more reliable classification of ECs, including 'multiple classifier' cases, which, based on our observations, tend to exhibit aggressive behavior. Additionally, our data highlight the complex genetic background of NSMP ECs, which can facilitate further stratification of tumors within this group and potentially help select patients for dedicated clinical trials., Competing Interests: Declarations. Institutional review board statement — Ethics approval: The study was approved by the Ethics Committee of the General University Hospital in Prague in compliance with the Helsinki Declaration (No. 2140/19 S-IV). The Ethics Committee waived the requirement for informed consent as according to the Czech Law (Act. no. 373/11 and its amendment Act no. 202/17); it is not necessary to obtain informed consent in fully anonymized studies. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

a-Methylacyl coenzyme A racemase (AMACR) is traditionally considered to be a marker of papillary renal cell carcinoma. However, AMACR expression can be seen in other renal tumors. The aim of this study was to investigate AMACR immunoreactivity within the spectrum of clear cell renal cell neoplasms. Fifty-three clear cell renal epithelial tumors were used in assembling the following four cohorts: low grade (LG) clear cell renal cell carcinoma (CCRCC), high grade (HG) CCRCC, CCRCC with cystic changes, and multilocular cystic renal neoplasm of low malignant potential (MCRNLMP). Representative blocks were stained for AMACR, using two different clones (SP52 and OV-TL12/30). There were at least some AMACR immunoreactivity in 77.8 % and 68.9 % of CCRCCs (using SP52 and OV-TL12/30 clone, respectively). Moderate to strong positivity, or positivity in more than one third of the tumor (even weak in intensity) was detected in 46.7 % of CCRCCs using SP52 and in 48.9 % of CCRCC using OV-TL12/30 clone. The highest AMACR reactivity was observed in HG CCRCC (60 % by SP52 and 66.7 % by OV-TL12/30). Strong and diffuse AMACR positivity was detected in 8.9 % of all CCRCCs. AMACR immunoreactivity in MCRNLMP was 37.5 % (SP52 clone) and 25 % (OV-TL12/30 clone). We demonstrated relatively high expression rate of AMACR in CCRCC, while very variable in intensity and distribution. This finding may have diagnostic implications especially in limited samples (i.e., core biopsies), as AMACR positivity does not exclude the diagnosis of CCRCC., Competing Interests: Declaration of competing interest The authors declare no financial interests or personal relationships that could have appeared to influence the work reported in this paper. Ondrej Fiala received honoraria from Novartis, Janssen, Merck and Pfizer for consultations and lectures unrelated to this project., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A syndromic association between a subset of testicular/paratesticular neoplasms is well established. Such examples include Carney complex and large cell calcifying Sertoli cell tumor, Peutz-Jeghers syndrome and intratubular large cell hyalinizing Sertoli cell neoplasia, and VHL syndrome and clear cell papillary cystadenoma of the epididymis.However, recent studies proposed potential novel links between some testicular and paratesticular neoplasms with certain tumor syndromes. While more studies are still needed to solidify these associations, recent research suggests that a subset of Leydig cell tumors may arise in patients with hereditary leiomyomatosis and renal cell carcinoma syndrome or that some seminomas may occur in Lynch syndrome patients. Additionally, an association between testicular sex cord stromal tumors and paratesticular sarcomas with Familial adenomatous polyposis syndrome and DICER1 syndrome, respectively, has been proposed as well. This review provides a comprehensive overview of the intricate relationship between familial syndromes and associated testicular and paratesticular tumors, shedding light on their clinicopathological and molecular characteristics., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Spermatocytic tumor (ST) is a rare type of germ cell tumor that occurs exclusively in the postpubertal testis and typically affects elderly men. Most STs are benign, but rare cases exhibit aggressive clinical behavior, often in association with transition to sarcomatoid histology. Limited molecular analyses have been performed on STs; therefore, their genomic and epigenomic features remain incompletely described. Twenty-seven samples from 25 individual patients were analyzed with a combination of DNA sequencing panels, genomic methylation profiling, SNP array, isochromosome (12p) [i(12p)] FISH, and immunohistochemistry. The series included five metastasizing tumors (three with sarcomatoid transformation, one anaplastic, and one conventional) and 20 non-metastasizing tumors (14 anaplastic and six conventional). Anaplastic tumors comprised a monomorphic population of intermediate-sized neoplastic cells, as previously described. Multiomic analyses demonstrated that there were two genomic subgroups of STs: one with diploid genomes and hotspot RAS/RAF variants and the other with global ploidy shift and absence of recurrent mutations. Relative gain of chromosome 9 was a consistent finding in both subgroups. A comparison of metastasizing and non-metastasizing cases demonstrated that aggressive behavior was associated with the acquisition of pathogenic TP53 mutations and/or relative gains of 12p/i(12p). In cases with sarcomatoid transformation, TP53 mutations seem to underlie the transition to sarcomatoid histology. Genomic methylation analysis demonstrated that aggressive cases with gains of 12p cluster closer to pure seminomas than to STs without gains of 12p. In conclusion, STs include two genomic subgroups, characterized by global ploidy shifts without recurrent mutations and diploid genomes with RAS/RAF hotspot mutations, respectively. Biologic progression was associated with relative gains of 12p and TP53 mutations. The findings in STs with relative gains of 12p suggest that they may exhibit biologic characteristics akin to those seen in germ cell neoplasia in situ-related germ cell tumors rather than non-germ cell neoplasia in situ-derived STs. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland., (© 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.)

Upper tract urothelial carcinoma (UTUC) is the third most common malignancy associated with Lynch syndrome (LS). The current European urology guidelines recommend screening for LS in patients with UTUC up to the age of 60 years. In this study, we examined a cohort of patients with UTUC for potential association with LS in order to establish the sensitivity of current guidelines in detecting LS. A total of 180 patients with confirmed diagnosis of UTUC were enrolled in the study during a 12-year period (2010-2022). Loss of DNA-mismatch repair proteins (MMRp) expression was identified in 15/180 patients (8.3%). Germline analysis was eventually performed in 8 patients confirming LS in 5 patients (2.8%), including 4 germline mutations in MSH6 and 1 germline mutation in MSH2. LS-related UTUC included 3 females and 2 males, with a mean age of 66.2 years (median 71 years, range 46-75 years). Four of five LS patients (all with MSH6 mutation) were older than 65 years (mean age 71.3, median 72 years). Our findings indicate that LS-associated UTUCs can occur in patients with LS older than 60 years. In contrast to previous studies which used mainly highly pre-selected populations with already diagnosed LS, the most frequent mutation in our cohort involved MSH6 gene. All MSH6 mutation carriers were > 65 years, and UTUC was the first LS manifestation in 2/4 patients. Using current screening guidelines, a significant proportion of patients with LS-associated UTUC may be missed. We suggest universal immunohistochemical MMRp screening for all UTUCs, regardless of age and clinical history., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Varicella zoster reactivation is an increasingly recognised event following mRNA COVID-19 vaccination. In addition, various ocular inflammatory and infectious adverse events following COVID-19 vaccination have been described in the literature. This case report describes acute retinal necrosis (ARN) secondary to varicella zoster virus (VZV) reactivation following COVID-19 mRNA vaccination., Case Description: A 42-year-old immunocompetent man developed left ARN 12 days following first dose of Pfizer BioNTech mRNA COVID-19 vaccination. Aqueous and vitreous tap polymerase chain reaction testing was positive for VZV. Good visual outcome was achieved with combination therapy, including intravitreal foscarnet, oral valaciclovir and prednisolone, topical dexamethasone and atropine, and barrier retinal laser. Second dose of the vaccine is planned under cover of high-dose oral valaciclovir therapy., Conclusion: This case illustrates the possible association between COVID-19 vaccination and potentially blinding VZV reactivation. Therefore, prompt ophthalmic assessment is recommended in patients with visual disturbance following COVID-19 vaccination.

Predicting the clinical behavior and trajectory of chromophobe renal cell carcinoma (ChRCC) by histologic features has so far proven to be challenging. It is known that ChRCC represents a heterogeneous group of neoplasms demonstrating variable, yet distinctive morphologic and genetic profiles. In this international multi-institutional study, we aimed to assess the impact of histologic diversity in ChRCC (classic/eosinophilic versus rare subtypes) on survival outcome. This is an international multi-institutional matched case-control study including 14 institutions, examining the impact of histologic subtypes of ChRCC on survival outcome. The study group (cases) included 89 rare subtypes of ChRCC. The control group consisted of 70 cases of ChRCC including classic and eosinophilic features, age- and tumor size-matched. Most of the rare subtypes were adenomatoid cystic/pigmented ChRCC (66/89, 74.2%), followed by multicystic ChRCC (10/89, 11.2%), and papillary ChRCC (9/89, 10.1%). In the control group, there were 62 (88.6%) classic and 8 (11.4%) eosinophilic ChRCC. There were no statistically significant differences between the study and control groups for age at diagnosis, gender distribution, tumor size, presence of tumor necrosis, presence of sarcomatoid differentiation, and adverse outcomes. No statistically significant differences were found in clinical outcome between the rare subtypes and classic/eosinophilic groups by tumor size, necrosis, and sarcomatoid differentiation. Further, no statistically significant differences were found in clinical outcome between the two groups, stratified by tumor size, necrosis, and sarcomatoid differentiation. Our findings corroborated previous studies that both sarcomatoid differentiation and tumor necrosis were significantly associated with poor clinical outcome in classic/eosinophilic ChRCC, and this was proven to be true for ChRCC with rare histologic subtypes as well. This study suggests that rare morphologic patterns in ChRCC without other aggressive features play no role in determining the clinical behavior of the tumor., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The morphologic diversity of chromophobe renal cell carcinoma (ChRCC) is well-known. Aside from typical morphology, pigmented adenomatoid, multicystic and papillary patterns have been described. Ten cases of CHRCC composed of small cell population in various percentages were analysed, using morphologic parameters, immunohistochemistry and next-generation sequencing (NGS) testing. Patients were five males and five females, with age ranging from 40 to 78years. The size of tumors ranged from 2.2 cm to 11 cm (mean 5.17 cm). Small cell component comprised 10 to 80% of the tumor volume, while the remaining was formed by cells with classic ChRCC morphology. The immunohistochemical profile of the small cell component was consistent with typical ChRCC immunophenotype, with CD117 and CK7 positivity. Neuroendocrine markers were negative. Mutations of 13 genes were found: DCIER1, FGFR3, JAK3, SUFO, FAM46C, FANCG, MET, PLCG2, APC, POLE, EPICAM, MUTYH and AR. However, only the PLCG2 mutation is considered pathogenic.The small cell variant of ChRCC further highlights and expand upon existing morphologic heterogeneity spectrum. Recognition of small cell variant of CHRCC is not problematic in tumors, where the "classic" CHRCC component is present. However, in limited material (i.e., core biopsy), this may present a diagnostic challenge. Based on the limited follow-up data available, it appears that the small cell tumor component had no impact on prognosis, since there was no aggressive behavior documented.   Awareness of this unusual pattern and applying additional sections to find classic morphology of ChRCC, as well as excluding neuroendocrine nature by immunohistochemistry, may help resolve difficult cases.

The 8th Edition of the American Joint Committee on Cancer (AJCC) Staging Manual designates discontinuous involvement of spermatic cord soft tissue by testicular germ cell tumors as a metastatic deposit. We conducted a retrospective international multi-institutional study to validate the current recommendations. Thirty-three (72%) nonseminomatous and 13 (28%) seminomatous testicular germ cell tumors were collected from 15 institutions in America, Europe, and Asia. Testicular tumor size ranged from 1.3 to 18.0 cm (mean: 6.1). Cases were classified as discontinuous involvement of spermatic cord soft tissue (n = 26), continuous cord involvement (n = 17), or cord lymphovascular invasion (n = 3). The mean follow-up was 39 months. Clinical stage for discontinuous involvement of spermatic cord soft-tissue patients was I (local disease) in 2/24 (8%), II (regional disease) in 6/24 (25%), and III (distant disease) in 16/24 (67%) cases; 16 (67%) patients presented with distant metastasis. Clinical stage for continuous cord involvement patients was I in 9/17 (53%), II in 4/17 (23%), and III in 4/17 (23%); 4 (23%) patients presented with distant metastasis. Disease progression was seen in 4 patients with discontinuous involvement of spermatic cord soft tissue and 5 with continuous cord-involvement (p = 0.699). When comparing discontinuous and continuous cord involvement, a significant difference was found in cord margin status (p = 0.044), spermatic cord tumor size (p = 0.016), lymph-node involvement (p = 0.037), distant metastasis (p = 0.010), individual clinical stage (p = 0.003), and nonadvanced vs. advanced disease (p = 0.003) at presentation. In multivariate analysis, after adjusting for age, histology, testicular tumor size, percent of embryonal carcinoma, lymphovascular invasion, and cord margin status, discontinuous involvement of spermatic cord soft tissue was significantly associated (p = 0.011) with advanced clinical stage at presentation. Our findings support the designation of metastatic disease for discontinuous involvement of spermatic cord soft tissue, as introduced by the 8th edition of the AJCC staging., (© 2021. The Author(s), under exclusive licence to United States & Canadian Academy of Pathology.)

Clear cell renal cell carcinoma (CCRCC) is well known for intratumor heterogeneity. An accurate mapping of the tumor is crucial for assessing prognosis, and perhaps this can be linked to potential success/failure of targeted therapies. We assembled a cohort of 7 CCRCCs with prominent vasculature and microvascular hyperplasia (ccRCCPV), resembling those seen in high grade gliomas. A control group of classic CCRCC with no variant morphologies was also included. Both groups were analyzed for clinicopathologic, morphologic, immunohistochemical, and molecular genetic features. No statistically significant differences in mRNA expression of studied genes between the two groups were found. Using NGS panel Trusight Oncology 500 (TSO500), only one clinically significant gene mutation, VHL c.263G > A, p. (Trp88Ter), was found. TMB (Tumor Mutation Burden) and MSI (MicroSatellite Instability) were low, and no copy number variations (CNVs) were detected in the study cohort. Prominent microvascular hyperplasia in CCRCC is a rare phenomenon. From molecular genetic point of view, these tumors do not appear to be different from classic CCRCC. Prognostically, they also demonstrated similar clinical behaviors., (Copyright © 2021 Elsevier Inc. All rights reserved.)

(1) Background: There are limited data concerning inter-tumoral and inter-metastatic heterogeneity in clear cell renal cell carcinoma (CCRCC). The aim of our study was to review published data and to examine mutation profile variability in primary and multiple pulmonary metastases (PMs) in our cohort of four patients with metastatic CCRCC. (2) Methods: Four patients were enrolled in this study. The clinical characteristics, types of surgeries, histopathologic results, immunohistochemical and genetic evaluations of corresponding primary tumor and PMs, and follow-up data were recorded. (3) Results: In our series, the most commonly mutated genes were those in the canonically dysregulated VHL pathway, which were detected in both primary tumors and corresponding metastasis. There were genetic profile differences between primary and metastatic tumors, as well as among particular metastases in one patient. (4) Conclusions: CCRCC shows heterogeneity between the primary tumor and its metastasis. Such mutational changes may be responsible for suboptimal treatment outcomes in targeted therapy settings.

So-called oncocytic papillary renal cell carcinoma (OPRCC) is a poorly defined variant of papillary renal cell carcinoma. Since its first description, several studies were published with conflicting results, and thus precise definition is lacking. A cohort of 39 PRCCs composed of oncocytic cells were analyzed. Cases were divided into 3 groups based on copy number variation (CNV) pattern. The first group consisted of 23 cases with CNV equal to renal oncocytoma. The second group consisted of 7 cases with polysomy of chromosomes 7 and 17 and the last group of 9 cases included those with variable CNV. Epidemiologic, morphologic and immunohistochemical features varied among the groups. There were not any particular histomorphologic features correlating with any of the genetic subgroups. Further, a combination of morphologic, immunohistochemical, and molecular-genetic features did not allow to precisely predict biologic behavior. Owing to variable CNV pattern in OPRCC, strict adherence to morphology and immunohistochemical profile is recommended, particularly in limited samples (i.e., core biopsy). Applying CNV pattern as a part of a diagnostic algorithm can be potentially misleading. OPRCC is a highly variable group of tumors, which might be misdiagnosed as renal oncocytoma. Using the term OPRCC as a distinct diagnostic entity is, thanks to its high heterogeneity, questionable., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Lambda interferons mediate antiviral immunity by inducing interferon-stimulated genes (ISGs) in epithelial tissues. A common variant rs368234815TT/∆G creating functional gene from an IFNL4 pseudogene is associated with the expression of major ISGs in the liver but impaired clearance of hepatitis C. To explain this, we compared Halo-tagged and non-tagged IFNL3 and IFNL4 signaling in liver-derived cell lines. Transfection with non-tagged IFNL3, non-tagged IFNL4 and Halo-tagged IFNL4 led to a similar degree of JAK-STAT activation and ISG induction; however, the response to transfection with Halo-tagged IFNL3 was lower and delayed. Transfection with non-tagged IFNL3 or IFNL4 induced no transcriptome change in the cells lacking either IL10R2 or IFNLR1 receptor subunits. Cytosolic overexpression of signal peptide-lacking IFNL3 or IFNL4 in wild type cells did not interfere with JAK-STAT signaling triggered by interferons in the medium. Finally, expression profile changes induced by transfection with non-tagged IFNL3 and IFNL4 were highly similar. These data do not support the hypothesis about IFNL4-specific non-canonical signaling and point out that functional studies conducted with tagged interferons should be interpreted with caution.

In somatotroph pituitary tumours, somatostatin analogue (SSA) therapy outcomes vary throughout the studies. We performed an analysis of cohort of patients with acromegaly from the Czech registry to identify new prognostic and predictive factors. Clinical data of patients were collected, and complex immunohistochemical assessment of tumour samples was performed (SSTR1-5, dopamine D2 receptor, E-cadherin, AIP). The study included 110 patients. In 31, SSA treatment outcome was evaluated. Sparsely granulated tumours (SGST) differed from the other subtypes in expression of SSTR2A, SSTR3, SSTR5 and E-cadherin and occurred more often in young. No other clinical differences were observed. Trouillas grading system showed association with age, tumour size and SSTR2A expression. Factors significantly associated with SSA treatment outcome included age, IGF1 levels, tumour size and expression of E-cadherin and SSTR2A. In the group of SGST, poor SSA response was observed in younger patients with larger tumours, lower levels of SSTR2A and higher Ki67. We observed no relationship with expression of other proteins including AIP. No predictive value of E-cadherin was observed when tumour subtype was considered. Multiple additional factors apart from SSTR2A expression can predict treatment outcome in patients with acromegaly., (© 2021 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

The existence of a true mixed germ cell-sex cord stromal tumor (MGSCT) of the testis remains controversial. Based on our experience with rare testicular tumors in this spectrum, we sought to perform a detailed clinicopathologic and molecular study of MGCSCT. Eight cases of testicular MGSCT were morphologically reviewed, screened for chromosomal aberrations (using array comparative genomic hybridization (aCGH) and low pass genomic sequencing), and analyzed by next generation sequencing (The Illumina TruSight Tumor 170). Immunohistochemistry for OCT3/4, Nanog, SALL4, DMRT1, and inhibin was performed on the cohort. Clinical data and follow-up were assessed by medical record review. All patients were karyotypically normal men aged 27-74 years (median 41). All tumors had a similar biphasic morphology characterized by various proportions of the sex cord component resembling granulosa cell tumor of adult type and the germ cell component cytomorphologically akin to spermatocytic tumor. Germ cells were haphazardly scattered throughout the tumor or arranged in larger groups, without tubular formation. In 4 cases, atypical mitoses were found within the germ cells. Additionally, in 2 cases there was invasion into the spermatic cord, adjacent hilar soft tissue and into the tumor capsule, which contained both tumor components. Immunohistochemically, focal nuclear expression of DMRT1 was found in the germ cell component in 7/7 analyzable tumors, while SALL4 was positive in 6 cases and negative in one case. All tumors were negative with OCT3/4 and Nanog. The sex cord stromal component had immunoreactivity for inhibin in 7/7 analyzable cases. Four of 8 cases were cytogenetically analyzable: 4/8 by low pass genomic sequencing and 2/8 by aCGH. The results of both methods correlated well, revealing mostly multiple chromosomal losses and gains. One case revealed loss of chromosome 21; 1 case had loss of chromosomes 21 and 22 and partial gain of 22; 1 case had loss of chromosomes 22 and Y, partial loss of X, and gain of chromosomes 20, 5, 8, 9, 12, and 13; and the remaining one gain of chromosomes 20, 3, 6, 8, 2x(9), 11, 2x(12), 13, 14, 18, and 19. Three cases were analyzable by NGS; clinically significant activating mutations of either FGFR3 or HRAS were not detected in any case. Follow-up was available for 4 patients (12, 24, 84, and 288 months) and was uneventful in all 4 cases. The identification of extratesticular invasion of both the germ cell and sex cord stromal components, the DMRT1 expression, and the presence of atypical mitoses in germ cells argue for the neoplastic nature of the germ cell component. The molecular genetic study revealing multiple chromosomal losses and gains in a subset of the cases provides the first evidence that molecular abnormalities occur in testicular MGSCT. Multiple chromosomal aneuploidies, namely, recurrent losses of chromosomes 21 and 22 and gains of 8, 9, 12, 13, and 20, indicate that the germ cell component might be related to the morphologically similar spermatocytic tumor, which is characterized by extensive aneuploidies including recurrent gains of chromosomes 9 and 20 and loss of chromosome 7. In summary, our data support that rare examples of true MGSCT of the testis do exist and they represent a distinct tumor entity with admixed adult-type granulosa cell tumor and spermatocytic tumor components.

The diagnosis of primary adenocarcinoma of the urinary bladder may be challenging in routine practice. These tumors may morphologically and immunohistochemically overlap with urachal adenocarcinoma and colorectal adenocarcinoma. Further, their genetic background is poorly understood. We systematically searched the PubMed database for results of complex genetic evaluation of primary bladder adenocarcinoma subtypes. Subsequently, we designed our own series of bladder lesions. We evaluated 36 cases: 16 primary enteric-type adenocarcinomas, 7 urachal enteric adenocarcinomas, 3 primary mucinous/colloid adenocarcinomas, and 10 intestinal-type metaplasia/villous adenoma. Detailed clinical data were collected, and all cases were examined using targeted next-generation sequencing. On the basis of the literature, the first mutated gene in these tumors was reported to be KRAS in 11.3% of cases, followed by TERT promoter mutations in 28.5%. In addition to KRAS and TERT, other genes were also found to be frequently mutated in primary bladder adenocarcinoma, including TP53, PIK3CA, CTNNB1, APC, FBXW7, IDH2, and RB1. In our series, the most frequent gene mutations in primary enteric-type adenocarcinomas were as follows: TP53 (56%); BRCA2, KMT2B (both 33%); NOTCH2, KDR, ARID1B, POLE, PTEN, KRAS (all 28%); in urachal enteric adenocarcinoma they were as follows: TP53 (86%); PTEN, NOTCH (both 43%); in primary mucinous/colloid adenocarcinomas they were as follows: KRAS, GRIN2A, AURKB (all 67%); and, in intestinal-type metaplasia/villous adenoma, they were as follows: APC, PRKDC (both 60%); ROS1, ATM, KMT2D (all 50%). No specific mutational pattern was identified using cluster analysis for any of the groups. Herein, we describe the pathologic features and immunohistochemical staining patterns traditionally used in the differential diagnoses of glandular lesions of the bladder in routine surgical pathology. We outline the mutational landscape of these lesions as an aggregate of published data with additional data from our cohort. Although diagnostically not discriminatory, we document that the most common genetic alterations shared between these glandular neoplasms include TP53, APC (in the Wnt pathway), and KRAS (in the MAPK pathway) mutations.

The karyotype of bone-marrow cells at the time of diagnosis is one of the most important prognostic factors in patients with myelodysplastic syndromes (MDS). In some cases, the acquisition of additional genetic aberrations (clonal evolution [CE]) associated with clinical progression may occur during the disease. We analyzed a cohort of 469 MDS patients using a combination of molecular cytogenomic methods to identify cryptic aberrations and to assess their potential role in CE. We confirmed CE in 36 (8%) patients. The analysis of bone-marrow samples with a combination of cytogenomic methods at diagnosis and after CE identified 214 chromosomal aberrations. The early genetic changes in the diagnostic samples were frequently MDS specific (17 MDS-specific/57 early changes). Most progression-related aberrations identified after CE were not MDS specific (131 non-MDS-specific/155 progression-related changes). Copy number neutral loss of heterozygosity (CN-LOH) was detected in 19% of patients. MDS-specific CN-LOH (4q, 17p) was identified in three patients, and probably pathogenic homozygous mutations were found in TET2 (4q24) and TP53 (17p13.1) genes. We observed a statistically significant difference in overall survival (OS) between the groups of patients divided according to their diagnostic cytogenomic findings, with worse OS in the group with complex karyotypes (P = .021). A combination of cytogenomic methods allowed us to detect many cryptic genomic changes and identify genes and genomic regions that may represent therapeutic targets in patients with progressive MDS., (© 2020 Wiley Periodicals, Inc.)

Although typically arranged in solid alveolar fashion, chromophobe renal cell carcinoma (RCC) may also show several other architectural growth patterns. We include in this series 8 chromophobe RCC cases with prominent papillary growth, a pattern very rarely reported or only mentioned as a feature of chromophobe RCC, which is lacking wider recognition The differential diagnosis of such cases significantly varies from the typical chromophobe RCC with its usual morphology, particularly its distinction from papillary RCC and other relevant and clinically important entities. Of 972 chromophobe RCCs in our files, we identified 8 chromophobe RCCs with papillary growth. We performed immunohistochemistry and array Comparative Genomic Hybridisation (aCGH) to investigate for possible chromosomal aberrations. Patients were 3 males and 5 females with age ranging from 30 to 84 years (mean 57.5, median 60 years). Tumor size was variable and ranged from 2 to 14 cm (mean 7.5, median 6.6 cm). Follow-up was available for 7 of 8 patients, ranging from 1 to 61 months (mean 20.1, median 12 months). Six patients were alive with no signs of aggressive behavior, and one died of the disease. Histologically, all cases were composed of dual cell population consisting of variable proportions of leaf-like cells with pale cytoplasm and eosinophilic cells. The extent of papillary component ranged from 15 to 100% of the tumor volume (mean 51%, median 50%). Sarcomatoid differentiation was identified only in the case with fatal outcome. Immunohistochemically, all tumors were positive for CK7, CD117 and Hale's Colloidal Iron. PAX8 was positive in 5 of 8 cases, TFE3 was focally positive 3 of 8 tumors, and Cathepsin K was focally positive in 2 of 8 tumors. All cases were negative for vimentin, AMACR and HMB45. Fumarate hydratase staining was retained in all tested cases. The proliferative activity was low (up to 1% in 7, up to 5% in one case). Three cases were successfully analyzed by aCGH and all showed a variable copy number variation profile with multiple chromosomal gains and losses. CONCLUSIONS: Chromophobe RCC demonstrating papillary architecture is an exceptionally rare carcinoma. The diagnosis can be challenging, although the cytologic features are consistent with the classic chromophobe RCC. Given the prognostic and therapeutic implications of accurately diagnosis other RCCs with papillary architecture (i.e., Xp11.2 translocation RCC, FH-deficient RCC), it is crucial to differentiate these cases from chromophobe RCC with papillary architecture. Based on this limited series, the presence of papillary architecture does not appear to have negative prognostic impact. However, its wider recognition may allow in depth studies on additional examples of this rare morphologic variant., Competing Interests: Declaration of competing interest All authors declare no conflict of interest., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Papillary renal cell carcinoma (PRCC) is currently a well-studied type of RCC. In addition to PRCC type 1, there are a number of other subtypes and variants of PRCCs which have been reported. We describe a series of 6 PRCCs with papillary, micropapillary and/or tubulopapillary architecture and prominent spindle cell stroma, resembling stroma in mixed epithelial and stromal tumor of the kidney (MESTK) or sarcomatoid RCC. Clinicopathologic, morphologic, immunohistochemical and molecular features were analyzed. All patients were males with an age range of 44-98 years (mean 65.3, median 65.5 years). Tumor size ranged from 2.4-11.4 cm (mean 5.8, median 4.5 cm). Follow-up data were available for 4 patients, ranging from 3 to 96 months (mean 42.75, median 36 months). Epithelial cells were mostly cylindrical with eosinophilic cytoplasm, showing nuclear grade 2 and 3 (ISUP/WHO). In all cases, loose to compact prominent stroma composed of spindle cells, without malignant mesenchymal heterologous elements was detected. No atypical mitoses were found, while typical mitoses were rare in both epithelial and stromal components. Epithelial cells were positive for CK7, AMACR, and vimentin in all cases, while negative for TFE3, HMB45, desmin, CD34, and actin. The stroma was positive for vimentin, actin and focally for CD34, while negative for CK7, AMACR, TFE3, HMB45, and desmin. Estrogen and progesterone receptors were completely negative. FH and SDHB expression was retained in all analyzable cases. Proliferative index was barely detectable in stromal component and low in epithelial component, ranging 0 to 5% positive stained cells/high power field. Copy number variation was variable with no distinct pattern. No mutations in CDKN2A, BAP1, MET were detected. PRCC with MESTK-like features is a distinct variant of PRCC mimicking MESTK. Our findings add to the body of literature on ever expanding variants of PRCCs. Both epithelial and stromal components lacked true Müllerian features, which was also proven by immunohistochemistry., Competing Interests: Declaration of competing interest All authors declare no conflict of interest., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In our routine and consultative pathology practices, we have noticed that a relatively high proportion of spindle cell predominant trichodiscomas demonstrate a remarkable stromal admixture of adipose tissue, which along with spindle cells, prominent collagen bundles and myxoid change closely resembles spindle cell lipoma (SCL). To clarify their possible relationship to SCL, 25 cases of trichodiscoma and fibrofolliculoma with stromal "lipomatous metaplasia" were collected and examined using immunohistochemical stains [CD34 and retinoblastoma-1 (RB1) protein] and fluorescence in situ hybridization (RB1 deletion). The patients ranged in age from 35 to 81 years (median 64 years). The male to female ratio was almost equal (14:11). All tumors with a known location were situated on the face with a special predilection for the nose. All cases were sporadic, with all patients having a single lesion and showing no clinical features of Birt-Hogg-Dubé syndrome. No case with available follow-up presented with a recurrence or an otherwise aggressive clinical course. Spindle cell stroma was immunohistochemically positive for CD34 in 16 of 20 cases, and 18 of 19 cases showed loss of RB1 staining in lesional spindle cells. Fluorescence in situ hybridization analysis detected RB1 gene heterozygous deletion in 6 of 20 cases. We conclude that despite the SCL-like appearance of the investigated cases, the majority of them supposedly represent genuine spindle cell predominant trichodiscomas with adipose tissue admixture. However, there was a subset of histopathologically indistinguishable cases with proved RB1 deletion, which likely represent SCL with trichodiscoma/fibrofolliculoma-like epithelial/adnexal induction rather than spindle cell predominant variant of trichodiscoma.

The authors report a case of bilateral diffuse uveal melanocytic proliferation associated with transitional cell carcinoma of the bladder. A novel imaging finding on indocyanine green angiography of a "string of sausages" pattern in the large choroidal vessels is described. This occurs in areas of alternating retinal pigment epithelial hypertrophy and destruction, which is likely to be its cause. To the authors' knowledge, it has not been previously described. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:525-528.]., (Copyright 2019, SLACK Incorporated.)

Clear cell renal cell carcinoma (CRCC) is well known for its intratumoral heterogeneity. Paneth-like cells (PLC) have been reported in variable organs (i.e., hepatobiliary, genitourinary, and female genital tract). In genitourinary system, it is possible to find PLCs in epididymis, urinary bladder and prostate. The objective of this study was to assess PLC in CRCCs 13 CRCCs with prominent PLC (CRCCPLC) were selected out of 1378 CRCCs in our registry. The tumors were analyzed using morphologic, immunohistochemical, ultrastructural, and molecular genetic methods. CRCCPLCs were mostly of low histologic grade (12/13). Immunohistochemical profile was compatible with classic CRCC. PLC constituted 10 to-70% of the tumor volume (mean 17.7%, median 10%). PLCs did not express neuroendocrine markers (chromogranin, synaptophysin, CD56, INSM-1). Ultrastructurally, PLCs were filled by membrane bounded vesicles of various sizes and were compatible with secretory type of cells. VHL mutation was found in 9/9 cases, and LOH3p was found in 6/8 analyzable cases. Conclusions: PLC morphology can variably be present in "classic" CRCC, even in a substantial proportion. Ultrastructurally, PLCs have all attributes of secretory cells. Preliminary follow up data showed that these tumors may not be associated with aggressive clinical behavior., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Aims: Primary renal well-differentiated neuroendocrine tumour (NET) (hereafter referred to as renal NET) is rare, with ~100 cases having been reported in the literature. There are also limited data on the molecular-genetic background of primary renal NETs., Methods and Results: We analysed 11 renal NETs by using next-generation sequencing (NGS) to identify characteristic genetic aberrations. All tumours were positive for synaptophysin, and also expressed insulinoma-associated protein 1 (10/11), chromogranin-A (8/11), and CD56 (3/11). Cytoplasmic positivity of CD99 was present in eight of 11 cases, and strong nuclear expression of α-thalassaemia/mental retardation syndrome X-linked (ATRX) was retained in all 11 cases. Molecular-genetic analysis of aberration of VHL gave negative results in all cases. Loss of heterozygosity on chromosome 3p21 was found in three of nine analysable cases. NGS was successful in nine cases, showing a total of 56 variants being left after the updated filtering process, representing an average of five variants per sample. All analysable cases were negative for ATRX and DAXX (death-domain associated protein X) mutations. The most frequently mutated genes were CDH1 and TET2, with three mutations in two cases. Mutations in AKT3, ROS1, PIK3R2, BCR and MYC were found in two cases. The remaining 41 genes were found to be mutated only in individual cases. In four cases, the mutations affected a subset of genes related to angiogenesis., Conclusions: Overall, the mutation profile of primary renal NETs is variable, and none of the studied genes or affected pathways seems to be specific for renal NET., (© 2019 John Wiley & Sons Ltd.)

Hereditary leiomyomatosis and renal cell carcinoma-associated renal cell carcinoma (HLRCC)/fumarate hydratase deficient renal cell carcinoma (FHRCC) is defined by molecular genetic changes (mutation/LOH in fumarate hydratase (FH) gene). We investigated chromosomal numerical aberration pattern (CNV) in FHRCC/HLRCC using array comparative genomic hybridization analysis and low pass whole genome sequencing. Genetic analysis was successfully completed in 12 tumors. Most common chromosomal aberrations detected were a complete or partial loss of chromosome 4 (5/12 cases), chromosome 15 (4/12 cases), and chromosomes 9, 13, and 14 (each in 3/12 cases), as well as a complete or partial gain of chromosome 17 (in 4/12 cases). No chromosomal losses or gains were detected in 4 cases. Copy number variation pattern in FHRCC/HLRCC appears to be highly variable and does not provide a useful diagnostic tool in identifying these cases. Immunohistochemical staining and especially molecular genetic evaluation of FH gene mutations/LOH remain the gold standard in identifying FHRCC/HLRCC., (Copyright © 2019. Published by Elsevier Inc.)

Aims: Current available data on cytokeratin 7 (CK7) immunostaining pattern in the clear cell renal cell carcinoma (RCC) spectrum is conflicting. The aim of this study was to assess CK7 immunoreactivity within the spectrum of clear cell renal neoplasms, including clear cell RCC, multicystic renal neoplasm of low malignant potential and clear cell papillary RCC-like tumours., Methods and Results: We analysed two clones of CK7 and two tumour blocks for a total of 75 cases divided into five distinct groups: (i) low-grade clear cell RCC, (ii) high-grade clear cell RCC, (iii) multicystic renal neoplasm of low malignant potential, (iv) clear cell RCC with cystic changes and (v) clear cell papillary RCC-like tumours. We found the highest CK7 reactivity in low-grade clear cell RCC, multicystic renal neoplasm of low malignant potential and clear cell papillary RCC-like groups, ranging from 60% to 93%., Conclusions: Our findings show that CK7 immunoreactivity in clear cell RCC is variable, and the extent of staining depends on the grade and architectural growth patterns of the tumours., (© 2018 John Wiley & Sons Ltd.)