[Clinicopathological and molecular features of metaplastic thymoma].

Objective: To investigate the clinicopathological features, and molecular genetic alterations of metaplastic thymoma (MT). Methods: A total of ten MT cases, diagnosed from 2011 to 2021, were selected from the Department of Pathology of Jinling Hospital, Nanjing University Medical School, Nanjing, China for clinicopathological and immunohistochemical (IHC) examination and clinical follow-up. Fluorescence in situ hybridization (FISH), next-generation sequencing (NGS), and YAP1 C-terminus (YAP1-CT) IHC were performed to detect YAP1::MAML2 fusions. Results: There were four males and six females, ranging in age from 29 to 60 years (mean 50 years, median 54 years). Microscopically, all tumors showed a typical biphasic morphology consisting of epithelial components and gradually or abruptly transitioning spindle cell components. The two components were present in varying proportions in different cases. Immunophenotypically, the epithelial cells were diffusely positive for CKpan, CK5/6 and p63. The spindle cells were diffusely positive for vimentin and focally positive for EMA. TdT was negative in the background lymphocytes. Ki-67 proliferation index was less than 5%. YAP1 and MAML2 break-apart FISH analyses showed that all ten cases had narrow split signals with a distance of nearly 2 signal diameters and may be considered false-negative. Using YAP1::MAML2 fusion FISH assays, abnormal fusion signals were observed in all the ten cases. NGS demonstrated YAP1::MAML2 fusions in all eight cases with adequate nucleic acids; in two cases the fusions were detected by DNA sequencing and in eight cases by RNA sequencing. All ten cases of MT demonstrated loss of YAP1 C-terminal expression in epithelioid cells. Conclusions: MT is a rare and low-grade thymic tumor characterized by a biphasic pattern and YAP1::MAML2 fusions. Break-apart FISH assays may sometimes show false-negative results due to the proximity of YAP1 and MAML2, while YAP1 C-terminal IHC is a highly sensitive and specific marker for MT. Loss of YAP1 C-terminal expression can also be used to screen YAP1::MAML2 fusions for possible MT cases.

[Skip metastasis at the esophageal resection margin in radical gastrectomy: clinical characteristics of 30 cases].

Objective: To summarize the clinical characteristics of patients with skip metastasis at esophageal resection margin during radical gastrectomy. Methods: This is a descriptive study of case series. Relevant data from 2006 to 2022 were collected from two major gastric cancer consultation and treatment centers: Nanjing Drum Tower Hospital and Jinling Hospital.Characteristics, surgical approach, number of dissected lymph nodes, immunohistochemical staining, and pathological staging were summarized and analyzed. The distribution of residual tumor cells at the esophageal margins was further analyzed at the cellular and tissue levels. Skip metastasis at the esophageal resection margin was defined as a negative esophageal margin with a positive margin in the cephalad donut. Results: Thirty (0.33%, 30/8972) eligible patients, 24 (80.0%) of whom were male, were identified in the two centers. The mean age was 63.9±11.0 years. Seventeen (56.7%) of these patients had papillary or tubular adenocarcinomas, including 13 (43.3%) poorly- and four (13.3%) moderately-differentiated tumors; four (13.3%) had signet-ring cell carcinomas; four (13.3%) mucinous adenocarcinomas; three (10.0%) mixed adenocarcinomas, including two with poorly-differentiated tubular adenocarcinomas mixed with signet-ring cell carcinoma and mucinous adenocarcinoma; and one had a poorly differentiated tubular adenocarcinoma mixed with signet-ring cell carcinoma. Two patients (6.7%) had other types of cancer, namely adenosquamous carcinoma in one patient and undifferentiated carcinoma in the other one. The predominant tumor sites were the lesser curvature (n=26, 86.7%) and the cardia (n=24, 80.0%). The mean tumor diameter was 6.6 cm, mean distance between tumor and esophageal resection margin was 1.5 cm, and proportions of tumor invasion into the dentate line, nerves, and vessels were 80.0% (24/30), 86.7%(26/30), and 93.3% (28/30), respectively. The mean number of lymph nodes resected was 20.4±8.9. The pathological stage was mainly T4 (n=18, 60.0%) and N3 (n=21, 70.0%), the median Ki67 was 52.7%, and the rates of positivity for HER2, EGFR, VEGFR, E-cadherin and PD-L1 were 40.0% (12/30), 46.7% (14/30), 80.0% (24/30), 86.7% (26/30) and 16.7% (5/30), respectively. At the cellular level, cancer cells were mainly distributed in small focal areas, as cell masses, or as tumor thrombi; large numbers of widely distributed atypic cells were seldom observed. At the tissue level, cancer cells were located in the mucosal layer in seven patients (23.3%), in the submucosal layer in 18 (60.0%), and in the muscular layer in five (16.7%); no cancer cells were identified in the outer membrane. Five of the seven tumors were located in the lamina propria, two in the muscularis mucosae, and none in the mucosal epithelium. Conclusion: Patients with skip metastasis at the esophageal resection margin at radical gastrectomy have unfavorable tumor biology and a high proliferation index, are at a late pathological stage, and the residual cancer is mostly located in the submucosa.

[Eosinophilic vacuolated tumor of the kidney: clinicopathological and molecular characteristics].

Objective: To study the clinicopathological features, immunophenotype, molecular changes, differential diagnosis and prognosis of eosinophilic vacuolated tumor (EVT) of the kidney. Methods: Four cases were collected retrospectively from 2014 to 2020 at Ningbo Diagnostic Pathology Center. The clinicopathologic features and immunophenotypic profile were studied by light microscopy and immunohistochemistry. Targeted next-generation sequencing (NGS) panel was used to detect cancer-associated mutation. Follow-up and literature review were also performed. Results: Among the 4 patients studied,2 were males and 2 were females. The age of the patients ranged from 44 to 63 years (the mean age: 51 years).Tumor size ranged from 1.5 to 4.2 cm (mean: 2.3 cm). Microscopically, tumors were well-circumscribed, unencapsulated. Thick-walled vessels and entrapped renal tubules were found within or at the periphery of the tumors. The tumors were predominantly composed of nest pattern, and focal tubular pattern. The tumor cells exhibited abundant, eosinophilic, granular cytoplasm and conspicuous, large nucleoli. Prominent intracytoplasmic vacuoles were seen. These cytoplasmic vacuoles varied in size and frequently coalesced into a large space. Loose fibromatous or hyaline stroma was focally noted. Immunohistochemically, the tumor cells in all cases exhibited a CD117+/CK7-phenotype. All cases were positive for CD10 and p504s. MTOR, S6 and cathepsin K were positive in 4 cases. TFE3, CA9, Melan A and HMB45 were negative in all cases. SDHB retained expression. NGS demonstrated MTOR mutations in all cases, and TSC2 mutation in 2 cases. Conclusions: EVT is a rarely oncocytic renal tumor with unique morphology, immunohistochemical phenotype, molecular profile and an indolent behavior. Recognition of the characteristics of this novel but rare entity will allow for better classification of renal tumors.

[Succinate dehydrogenase-deficient renal cell carcinoma:a clinicopathological, ultrastructural and molecular analysis].

Objective: To investigate the clinicopathological features, immunophenotype, ultrastructure, genetic alterations and prognosis of succinate dehydrogenase-deficient renal cell carcinoma (SDH RCC). Methods: A total of 11 SDH RCCs, diagnosed from 2010 to 2019, were selected from the Department of Pathology of Nanjing Jingling Hospital, Nanjing University School of Medicine for clinicopathologic, immunohistochemical (IHC), ultrastructural investigation and follow-up. The molecular features of seven cases were analyzed by the panel-targeted DNA next generation sequencing (NGS). Results: There were seven males and four females, with ages ranging from 24 to 62 years (mean 41.4 years, median 41 years). Microscopically, SDH RCC was mainly composed of solid and tubular structures with local cystic change. Four cases showed nested or trabecular structure distributed in a loose hypocellular connective tissue or around scar, similar to oncocytoma. The neoplastic cells demonstrated flocculent eosinophilic cytoplasm with typical intracytoplasmic vacuoles. Immunohistochemically, eight cases were negative for SDHB; three cases showed focal and weak expression, whereas normal renal tubular and vascular endothelial cells demonstrated strong cytoplasmic staining. NGS of DNA targeted-panel detected pathogenic mutations of SDHB gene in seven cases (including three cases with equivocal IHC expression of SDHB), without any mutations in other SDH related genes. There were four cases of SDHB missense mutation, one case of frameshift mutation, one case of splicing mutation, and one case of acquired stop codon mutation. Conclusions: SDH RCC is a distinct variant of RCCs with genetic tendency or with hereditary cancer syndrome. NGS is recommended to detect the related gene mutations for a definitive diagnosis. The patients should be closely followed up.

[Papillary renal neoplasm with reverse polarity: a clinicopathological analysis].

Objective: To study the clinical pathological characteristics, immunophenotype, molecular changes and prognosis of the papillary renal neoplasm with reverse polarity (PRNRP). Methods: Nine cases of PRNRP, diagnosed from 2013 to 2019, were retrieved from the Department of Pathology of Nanjing Jinling Hospital, Nanjing University School of Medicine. Histomorphology, immunophenotype and molecular genetics were analyzed with review of the literatures. Results: There were five male and four female patients, aged from 49 to 70 years, with an average age of 60.1 years. During a mean follow-up of 29 months, one patient died for other cause, and the others survived without disease. Microscopically, the tumor cells arranged in papillary structure with a fibrovascular core, the surface of which was covered with a single layer of cuboidal or columnar cells. The most prominent feature was that the tumor nuclei located at the top of the cytoplasm far from the basement membrane, and they were monotonous in size and arranged neatly with no or few nucleoli. Immunohistochemically, all nine cases of PRNRP showed diffuse positive expression of CK7 and E-cadherin, various degrees of P504s expression, and no expression of CD10 and CD117, with a Ki-67 index of 1%-3%. Unlike other papillary renal cell carcinoma, the nine cases of PRNRP all showed characteristic positive expression of GATA3. The fluorescence in situ hybridization assay showed that the majority of PRNRPs (8/9) did not have triploids on chromosomes 7 and 17. The sequencing of the KRAS gene confirmed the presence of a nonsense KRAS mutation in 8 of the 9 cases. Conclusions: PRNRP is a subtype of papillary renal cell carcinoma with characteristic morphological, immunophenotypic and molecular features, and indolent behaviors. More data are needed to define PRNRP as "carcinoma", and a definitive diagnosis of PRNRP is of great significance for proper treatment choice and accurate prognostication.

[Anaplastic lymphoma kinase-translocation renal cell carcinoma: clinical and pathological analysis].

Objective: To investigate the clinicopathological features, molecular characteristics, differential diagnosis and prognosis of anaplastic lymphoma kinase (ALK)-translocation renal cell carcinoma. Methods: Two cases of ALK-translocation renal cell carcinoma diagnosed from January 2011 to December 2020 were retrospectively analyzed to characterize their morphological features, immunohistochemical expression and prognosis. Multiple molecular studies including fluorescence in situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR), and next-generation sequencing were performed to characterize the genetic alterations. Results: Two patients included one male and one female, with 59 and 57 years old, respectively. Morphologically, case 1 resembled collecting duct carcinoma or renal medullary carcinoma, which demonstrated tubular, microcapsule and reticular structures, with a remarkable myxoid background and lymphocytes infiltration; case 2 resembled Xp11.2 translocation renal cell carcinoma or type 2 papillary renal cell carcinoma, which demonstrated tubular papillary and focal solid structures, with flocculent cytoplasm and many foamy histiocytes, but without myxoid background and lymphocytes infiltration. Immunohistochemistry showed strongly positive expression of ALK. CK7, E-cadherin, vimentin, PAX8 and CD10 showed various degrees of expression, and other antibodies were nonreactive. A variety of molecular assays showed definite ALK gene translocation, with rare VCL-ALK gene fusion (VCL exon and 16-ALK exon 20) in case 1, and EML4-ALK gene fusion (EML4 exon and 2-ALK exon 20) in case 2. Conclusions: ALK-translocation renal cell carcinoma is rare with various morphological features, and is easy to miss and misdiagnose. The characteristic ALK expression and molecular detection of ALK translocation are helpful for diagnosing this type of renal cell carcinoma.

[Intestinal flora polymorphisms with different lesional stages in an animal model of MAFLD].

Objective: To study the intestinal flora specific differences with different lesional stages of metabolic (disorder) associated fatty liver disease (MAFLD), namely simple steatosis and steatohepatitis, so as to provide a new direction for MAFLD-related intestinal flora transplantation and targeted therapy. Methods: Mice were fed with normal diet, methionine-choline deficient diet (MCD) and a high-fat high-fructose diet (HFHF) for 12 weeks to construct simple steatosis and steatohepatitis models. HE and Sirius scarlet staining was performed to observe the liver pathological changes. The qPCR method was used to evaluate inflammation and liver fibrosis factors. A fully automatic biochemical analyzer was used to detect changes in liver transaminase and blood lipids. 16S rRNA sequencing method was used to observe the intestinal flora differences in the feces of each group of mice. The comparison of means between two groups was performed by t-test, and the comparison of means between multiple groups was performed by one-way analysis of variance. Kruskal-Wallis rank sum test was used for non-normally distributed data. Results: NAFLD scores were determined with pathological sections (HE and Sirius scarlet staining) of mice liver, which showed that the inflammation and liver fibrosis scores of the MCD and HFHF groups were 2.12 ± 0.18 and 1.06 ± 0.24, and 2.22 ± 0.16 and 0.46 ± 0.10, respectively. The degree of liver inflammation and fibrosis was significantly higher in the MCD than the HFHF group (P < 0.001 and P < 0.01). Lipid deposition was higher in the HFHF than the MCD group (P < 0.001), and the scores were 2.36 ± 0.17 and 1.60 ± 0.24 respectively. Simultaneously, the inflammatory [tumor necrosis factor-A (TNF-a), chemokine factor-2 (CXCL-2)] and hepatic fibrosis indicators [vascular smooth muscle actin alpha (a-SMA) and connective tissue growth factor (CTGF)] had confirmed the above-mentioned results at the transcription level. Moreover, the intestinal flora diversity was reduced (P < 0.05) in the MCD group than the HFHF group, and the Simpson and Shannon index were 0.31 ± 0.10 and 0.42 ± 0.05, and 2.03 ± 0.33 and 1.70 ± 0.28, respectively, and the differences were significant between different intestinal flora groups. The levels of Desulfovibrio, Odoribacter, and Roseburia flora were significantly increased in the HFHF than the MCD group, and the levels of Faecalibaculum, Parasutterella, Alipis, Butyricimonas_virosa, Turicibacter_sp, and Romboutsia_ilealis were significantly increased in the MCD than the HFHF group, and the difference was statistically significant (P < 0.05). Conclusion: There are significant differences in intestinal flora diversity between simple steatosis and steatohepatitis models. Therefore, clarifying the difference between the two may provide a new direction for the stage manner treatment of MAFLD.

[Expression of NR4A3/NOR-1 in acinic cell carcinoma of the salivary gland].

Objective: To investigate the diagnostic role of NR4A3/NOR-1 immunohistochemistry in acinic cell carcinoma (AciCC) of the salivary gland. Methods: A total of 142 tumors were collected from 2004 to 2020 at Nanjing Jinling Hospital, including 24 cases of AciCCs, 12 salivary gland secretory carcinomas,14 salivary duct carcinomas,16 adenoid cystic carcinomas,3 basal cell carcinomas,13 mucoepidermoid carcinomas,7 myoepithelial carcinomas,15 pleomorphic adenomas,15 warthin tumor, 8 myoepithelioma,8 basal cell adenomas, and 7 oncocytomas; 28 normal salivary gland tissues and 2 pancreatic AciCC were also included. Results: NR4A3/NOR-1,a nuclear marker,was positive in 91.7% (22/24) of AciCC of the salivary gland,while DOG1,a membranous and cytoplasmic marker, demonstrated a sensitivity of 95.8% (23/24);there was no significant difference in the overall positive rates(P=0.551), but the stain pattern was different. NR4A3/NOR-1 was negative in normal salivary gland tissues and any other types of tumors in the salivary gland; however,DOG1 showed apical staining in the acinar cells in the salivary gland,as well as salivary gland secretory carcinomas,adenoid cystic carcinomas,basal cell carcinomas,mucoepidermoid carcinomas,myoepithelial carcinomas and basal cell adenomas(P<0.001). NR4A3/NOR-1 showed a high sensitivity(91.7%) and specificity(100%) to identify AciCC of the salivary gland,and in combination with DOG1, the sensitivity increased to 100%. Furthermore, NR4A3/NOR-1 were only positive for AciCC arising from salivary glands but not pancreas(0/2)(P=0.018). Conclusion: NR4A3/NOR-1 is a special and sensitive biomarker for AciCC of salivary glands; combined NR4A3/NOR-1 and DOG1 can be an ideal diagnostic immunohistochemical panel for AciCC.

[Xp11 neoplasma with melanocytic differentiation: a clinicopathological analysis].

Objective: To investigate the clinical, histologic and immunophenotypic features, genetic alterations and prognosis of the rare Xp11 neoplasm with melanocytic differentiation. Methods: Twenty-one cases were selected from the Department of Pathology, Jingling Hospital, Nanjing University School of Medicine from May 2008 to May 2018. The clinicopathologic, immunohistochemical, molecular analysis and follow-up details were collected. Results: There were 7 males and 14 females, with their ages ranging from 4 to 57 years (mean 32.8 years). The tumors were located in kidney (11 cases), pelvis (three cases), and in pancreas, retroperitoneum, adrenal gland, small intestine, prostate, cervix and appendix (one case each). Microscopically, most tumors shared similar morphology such as purely nested or sheet-like architectures separated by a delicate vascular network, purely epithelioid cells with clear to granular eosinophilic cytoplasm, lacks of papillary structures, spindle cell or fat components, uniform round to oval nuclei with small visible nucleoli, and in most of them (16/21) melanin pigment. Immunohistochemically, all cases showed moderately (2+) or strongly (3+) positive staining for TFE3 and Cathepsin K. HMB45 and Melan A were focally expressed in three of 21 cases, while the remaining cases showed typically moderate(2+) or strong (3+) expression. None of the cases were immunoreactive for SMA, desmin, CKpan, S-100 and PAX8. All cases showed TFE3 rearrangement using fluorescence in-situ hybridization (FISH). Fusion FISH assays detected SFPQ-TFE3 gene fusion in 16 cases, NONO-TFE3 gene fusion in two, ASPL-TFE3 and MED15-TFE3 gene fusions in one case each. Polymerase chain reaction and direct sequencing detected SFPQ-TFE3 gene fusion in nine cases, NONO-TFE3 and MED15-TFE3 gene fusions in one case each. Clinical follow-up was available for 15 patients for 12 to 74 months. Six patients died of the disease; and three had recurrences and/or metastases. Six patients were alive with no evidence of disease after initial resection. Conclusions: Xp11 neoplasm with melanocytic differentiation has unique morphologic, immunophenotypic and genetic characteristics. The tumor is aggressive, and should be differentiated from Xp11 translocation RCC and perivascular epithelioid cell tumor.

[Eosinophilic solid and cystic renal cell carcinoma: clinicopathological analysis and molecular characterization].

Objective: To study the clinicopathological features, immunohistochemical phenotype, molecular changes, differential diagnosis and prognosis of eosinophilic solid and cystic renal cell carcinoma (ESC RCC). Methods: A total of 15 cases were selected from 2005 to 2019 at Nanjing Jinling Hospital,Nanjing University School of Medicine for clinicopathological and immunohistochemical analysis, 10 of which were subject to cancer-associated mutation analysis using targeted next-generation sequencing (NGS) panel. A literature review was also performed. Results: The patients' ages ranged from 15 to 68 years (mean, 33 years). The male-to-female ratio was 1.1∶1.0. During a mean follow-up of 22 months, none of the patients developed tumor recurrence, progression or metastasis. Histologically, the tumors typically demonstrated solid and cystic architectures and the neoplastic cells contained voluminous eosinophilic cytoplasm with prominent granular cytoplasmic stippling. Immunohistochemically, tumor cells in all cases were immunoreactive for CK20. Signal pathway related protein mTOR and S6 were positive in 14/15 and 6/15 cases, respectively. Cathepsin K, Melan A and HMB45 were at least focally positive in 12/15, 6/15 and 2/15 cases, respectively. CK7 and CD10 showed focal immunostain positivity in some cases, while TFE3, TFEB, CA9 and CD117 were negative in all cases. NGS demonstrated TSC1/TSC2 mutations in all tested cases (10/10). Conclusions: ESC RCC is a rare tumor that tends to occur in young patients with an indolent behavior. Diagnosis can be established by its distinct clinical and histopathologic findings, immunohistochemical phenotype and molecular genetics. The tumor may be considered as a new subtype of RCC.

[Clinicopathologic and molecular features of myoepithelial tumors of salivary glands].

Objective: To investigate the clinicopathological, and molecular characteristics of myoepithelial tumors (MTs) of salivary glands. Methods: A total of 37 MTs cases including 13 malignant epithelial tumors (MMTs) and 24 benign epithelial tumors (BMTs) of salivary glands were identified from the archives of the Department of Pathology, General Hospital of Eastern Theater Command, dating from 2006 to 2016. Clinical features, histological patterns, immunohistochemical characteristics and status of EWSR1 gene rearrangement by fluorescence in situ hybridization (FISH) analysis were reviewed in all cases. Results: Clinically, 37 MTs cases mainly occurred in the parotid glands, when most of the patients presented with painless masses. Of the 13 MMTs cases, male to female ratio was 7∶6, and the median age was 62 years old. Of the 24 BMTs cases, male to female ratio was 5∶7, and the median age was 54 years old. Immunohistochemically, 37 MTs cases were positive for CKpan, and at least one myoepithelial marker. Twenty six of 37 MTs cases were analyzable for the EWSR1 gene break by FISH. Based on the previous evaluation criterion, the EWSR1 translocation was detected in 4 cases of 11 MMTs, and 4 cases of 15 BMTs. According to the main histological composition of tumor cells, 4 EWSR1-positive MMTs covered 2 clear-cell cases and 2 epithelioid-cell cases, when 4 EWSR1-positive BMTs covered 2 clear-cell cases, 1 plasmacytoid-cell case, and 1 spindle-cell case. Conclusions: Males and females are affected equally. MTs express immunoreactivity for CKpan, and at least one myoepithelial marker. The EWSR1 rearrangement is present in a subset of MTs, with variable morphological characteristics, and has no statistical significance on clinical behavior.

[Clinicopatholigic features of renal cell carcinoma associated with chromosome X inversion harboring gene fusions involving TFE3].

Objective: To study the clinicopathologic features, immunophenotype, characteristic FISH pattern and prognosis of renal cell carcinoma (RCC) associated with chromosome X inversion harboring gene fusions involving TFE3. Methods: Ten cases of NONO-TFE3 RCC and four cases of RBM10-TFE3 RCC were investigated at Nanjing Jinling Hospital from 2009 to 2016 by clinicopathological findings, immunohistochemistry, and genetic analysis. Results: Morphologically, the distinct pattern of secretory endometrioid subnuclear vacuolization was overlapped with clear cell papillary RCC, and often accompanied by sheets of epithelial cells in NONO-TFE3 RCC. Most cases of RBM10-TFE3 RCC presented with the biphasic feature that acinar, tubular and papillary patterns of epithelioid cells combined with sheets of small cells with "pseudorosette-like" architectures. In addition, cytoplasmic vacuolization, nuclear groove, and psammoma bodies were also observed. Immunohistochemically, all NONO-TFE3 RCC cases were immunoreactive for TFE3, CD10, RCC markers, and PAX8, and negative for CK7, Cathepsin K, Melan A, HMB45, Ksp-cadherin, vimentin, and CD117. All 4 cases of RBM10-TFE3 RCC showed moderate to strong immunoreactivity for TFE3, Cathepsin K, CD10, Ksp-cadherin, E-cadherin, P504s, RCC marker, PAX8, and vimentin but negative for TFEB, HMB45 and CK7. CKpan and Melan A were at least focally expressed. The antibody to Ki-67 showed labeling of 3%-8% (mean 5%). There were some expression discrepancies of immunochemistry between different histological patterns. PAX8, CKpan, P504s, and Ksp-cadherin were expressed in epithelioid areas but not in small-cell areas. Ki-67 labeling index of epithelioid areas was higher than that in small-cell areas. In molecular analysis, NONO-TFE3 fusion transcripts were identified in 6 patients. The fusion points were between exon 7 of NONO and exon 6 of TFE3 in 5 patients and between exon 9 of NONO and exon 5 of TFE3 in one patient. All 4 cases of RBM10-TFE3 RCC demonstrated to have RBM10-TFE3 fusion transcripts and the fusion points were between exon 5 of TFE3 and exon 17 of RBM10. Using TFE3 break-apart FISH assay, all 10 cases of NONO-TFE3 RCC showed characteristic patterns of equivocal split signals with a distance of nearly 2 signal diameters. All 4 cases of RBM10-TFE3 RCC showed colocalized or subtle split signals with a distance of <1 signal diameter, which was considered as negative results. Long-term follow-up was available for 7 patients of NONO-TFE3 RCC and 4 patients of RBM10-TFE3 RCC. All patients were alive with no evidence of disease. Conclusions: Two rare genotypes, NONO-TFE3 RCC and RBM10-TFE3 RCC, are reported in this study. Both of these two tumors show specific morphology and good prognosis, along with the positive TFE3 staining and the equivocal or false-negative TFE3 FISH results, which could be missed. PCR detection or next-generation sequencing can determine the genotype.

Identification of a glutathione S-transferase gene of Physarum polycephalum as a biomarker for nanosized TiO2 exposure under dark conditions.

In this study, a glutathione S-transferase gene (gst) from sensitive Physarum polycephalum was selected for its ability to detect nanosized TiO2 (nTiO2 ) exposure under dark conditions. The concentration of nTiO2 (25, 40 and 60 nm) for subsequent assays was first determined (5-18 mg ml-1 ) and total GST enzyme activity of P. polycephalum was confirmed to be increased 6-44 fold in groups treated with nTiO2 . Second, an RNA-seq study was performed to identify candidate gst genes before isolation of an optimum gst gene of P. polycephalum (Ppgst), which encoded 223 amino acids. Third, the transcriptional level of the Ppgst gene was further confirmed to be positively correlated with nTiO2 exposure within the concentration range of (5-15 mg ml-1 ) by qPCR. In conclusion, these results indicated that the transcriptional level of Ppgst can reflect nTiO2 exposure, suggesting that it may be employed as a new biomarker for nTiO2 pollution under dark conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: This study identifies a new gst gene for indicating nanosized TiO2 under dark conditions and provides a new option for detection of nanosized TiO2 pollution under dark conditions.