Genomic Evidence for the Complex Evolutionary History of Macaques (Genus Macaca).

The genus Macaca is widely distributed, occupies a variety of habitats, shows diverse phenotypic characteristics, and is one of the best-studied genera of nonhuman primates. Here, we reported five re-sequencing Macaca genomes, including one M. cyclopis, one M. fuscata, one M. thibetana, one M. silenus, and one M. sylvanus. Together with published genomes of other macaque species, we combined 20 genome sequences of 10 macaque species to investigate the gene introgression and genetic differences among the species. The network analysis of the SNV-fragment trees indicates a reticular phylogeny of macaque species. Combining the results from various analytical methods, we identified extensive ancient introgression events among macaque species. The multiple introgression signals between different species groups were also observed, such as between fascicularis group species and silenus group species. However, gene flow signals between fascicularis and sinica group were not as strong as those between fascicularis group and silenus group. On the other hand, the unidirect gene flow in M. arctoides probably occurred between the progenitor of M. arctoides and the common ancestor of fascicularis group. Our study also shows that the genetic backgrounds and genetic diversity of different macaques vary dramatically among species, even among populations of the same species. In conclusion, using whole genome sequences and multiple methods, we have studied the evolutionary history of the genus Macaca and provided evidence for extensive introgression among the species.

Transcriptome analysis indicates the mechanisms of BmNPV resistance in Bombyx mori midgut.

Bombyx mori nucleopolyhedrovirus (BmNPV) caused serious economic losses in sericulture. Analyzing the molecular mechanism of silkworms (B. mori) resistance to BmNPV is of great significance for the prevention and control of silkworm virus diseases and the biological control of agricultural lepidopteran pests. In order to clarify the defense mechanisms of silkworms against BmNPV, we constructed a near isogenic line BC8 with high resistance to BmNPV through the highly BmNPV-resistant strain NB and the highly BmNPV-susceptible strain 306. In this study, RNA-Seq technique was used to analyze the transcriptome level differences in the midgut of BC8 and 306 following BmNPV infection. A total of 1350 DEGs were identified. Clustering analysis showed that these genes could be divided into 8 clusters with different expression patterns. Functional annotations based on GO and KEGG analysis indicated that they were involved in various metabolism pathways. Finally, 32 BmNPV defense responsive genes were screened. They were involved in metabolism, reactive oxygen species (ROS), signal transduction and immune response, and insect hormones. The further verification shows that HSP70 should participate in resistance responses of anti-BmNPV. These findings have paved the way in further functional characterization of candidate genes and subsequently can be used in breeding of BmNPV resistance dominant silkworms.

EphB3 protein is a potential ancillary diagnostic biomarker for thyroid cancers.

OBJECTIVE: To investigate the expression of ephrin type B receptor 3 (EphB3) in thyroid tumors and its usage as an ancillary diagnostic biomarker for thyroid tumors. METHODS: Formalin-fixed and paraffin-embedded (FFPE) tissue samples (78 cases) and FNAC samples (57 cases) were assessed with the EphB3 antibody using immunohistochemistry. PTC and other thyroid follicular tumors were compared regarding their EphB3 expression. Sanger sequencing was used to assess for the presence of a BRAF V600E mutation. RESULTS: EphB3 was positive in 81.8 % (27/33) of papillary thyroid carcinoma (PTC), 83.3 % (5/6) of medullary thyroid carcinoma (MTC), 25 % (1/4) of hyperplastic/adenomatoid nodule (HN), 14.3 % (1/7) of follicular adenoma (FA), and negative in follicular tumors of uncertain malignant potential (FT-UMP) (0/13), noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP) (0/7), thyroid follicular carcinoma (TFC) (0/4), Hashimoto's thyroiditis (0/4), and normal thyroid follicular tissues (0/33). In cellular blocks, EphB3 was positive in 87.1 % (20/23) of PTC, 75 % (3/4) of MTC, 20 % (2/10) of HN, and negative in atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) (0/20) and normal thyroid follicular cells (0/10). CONCLUSION: EphB3 is expressed in the majority of PTC, but less so in benign follicular nodules. EphB3 expression in fine needle aspiration cytology (FNAC) specimens can be used as a diagnostic tool to differentiate thyroid cancer from other follicular lesions in its differential diagnosis, especially AUS/FLUS and PTC.

Loss of YAP1 C-terminus expression as an ancillary marker for metaplastic thymoma: a potential pitfall in detecting YAP1::MAML2 gene rearrangement.

AIMS: Metaplastic thymoma is a rare thymic tumour characterized by Yes Associated Protein 1 (YAP1) and Mastermind Like Transcriptional Coactivator 2 (MAML2) gene fusions resulting from an intrachromosomal inversion of chromosome 11. Immunohistochemistry with an antibody directed against the C-terminus of YAP1 has shown loss of expression in YAP1-rearranged vascular neoplasms, poromas, and porocarcinomas. This study aimed to validate an anti-YAP1 C-terminal antibody as an ancillary immunohistochemical marker for the diagnosis of metaplastic thymoma. MATERIALS AND METHODS: Ten metaplastic thymomas were selected for the current study. Fluorescence in situ hybridization (FISH), next-generation sequencing (NGS), and reverse transcription-polymerase chain reaction (RT-PCR) analyses were performed to detect YAP1::MAML2 fusions. We then performed immunohistochemistry to detect YAP1 C-terminus expression in 10 metaplastic thymomas, 50 conventional thymomas (10 each of type A thymoma, type AB thymoma, type B1 thymoma, type B2 thymoma, and type B3 thymoma) and seven thymic carcinomas. RESULTS: All 10 cases showed narrow split signals with a distance of nearly two signal diameters and sometimes had false-negative results in YAP1 and MAML2 break-apart FISH (BA-FISH). Abnormal colocalized signals of the YAP1::MAML2 fusion were observed in all 10 cases using fusion FISH (F-FISH) assays. Eight of 10 cases with adequate nucleic acids were successfully sequenced and all showed YAP1::MAML2 fusions; in two cases the fusions were detected by both DNA and RNA sequencing and in six cases by RNA sequencing only. YAP1::MAML2 fusion transcripts were identified in four cases by RT-PCR. Metaplastic thymoma showed loss of YAP1 C-terminus expression in all 10 (100%) cases. All other thymic neoplasms showed retained YAP1 C-terminus expression. CONCLUSION: YAP1 C-terminus immunohistochemistry is a highly sensitive and specific ancillary marker that distinguishes metaplastic thymoma from its mimics. BA-FISH assays could not effectively detect YAP1::MAML2 fusions due to the proximity of the two genes. Loss of YAP1 C-terminus expression is a reliable surrogate for the detection of YAP1::MAML2 fusions in metaplastic thymoma.

First complete mitochondrial genome of Rhodinia species (Lepidoptera: Saturniidae): genome description and phylogenetic implication.

To explore the characteristics of the mitochondrial genome (mitogenome) of the squeaking silkmoths Rhodinia, a genus of wild silkmoths in the family Saturniidae of Lepidoptera, and reveal phylogenetic relationships, the mitogenome of Rhodinia fugax Butler was determined. This wild silkmoth spins a green cocoon that has potential significance in sericulture, and exhibits a unique feature that its larvae can squeak loudly when touched. The mitogenome of R. fugax is a circular molecule of 15,334 bp long and comprises 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and an A + T-rich region, consistent with previous observations of Saturniidae species. The 370-bp A + T-rich region of R. fugax contains no tandem repeat elements and harbors several features common to the Bombycidea insects, but microsatellite AT repeat sequence preceded by the ATTTA motif is not present. Mitogenome-based phylogenetic analysis shows that R. fugax belongs to Attacini, instead of Saturniini. This study presents the first mitogenome for Rhodinia genus.

Malignant melanotic Xp11 neoplasms exhibit a clinicopathologic spectrum and gene expression profiling akin to alveolar soft part sarcoma: a proposal for reclassification.

The classification of the distinct group of mesenchymal neoplasms, first described as 'Xp11 translocation perivascular epithelioid cell tumor (PEComa)' and for which the term 'melanotic Xp11 neoplasm' or 'Xp11 neoplasm with melanocytic differentiation' has recently been proposed, remains challenging and controversial. We collected 27 melanotic Xp11 neoplasms, the largest series to date, for a comprehensive evaluation. Fourteen of the cases, together with eight alveolar soft part sarcomas (ASPS), nine conventional PEComas and a control group of seven normal tissues were submitted to RNA sequencing. Follow-up available in 22 patients showed 5-year overall survival and 5-year disease-free survival of 47.6 and 35.7%, respectively, which were similar to ASPS and significantly worse than conventional PEComa. Univariate analysis of location (occurring in the kidney versus not kidney), infiltrative growth pattern, nuclear pleomorphism, mitotic activity ≥2/50 high-power fields (HPF), necrosis and lymphovascular invasion were found to be associated with overall survival and/or disease-free survival. Multivariate analysis identified that location was the only factor found to independently correlate with disease-free survival. More importantly, RNA sequencing-based clustering analysis segregated melanotic Xp11 neoplasm and ASPS from other tumors, including conventional PEComa and Xp11 translocation renal cell carcinoma, and formed a compact cluster representative of the largely similar expression signature. Here we clearly define the true biologic nature of melanotic Xp11 neoplasms which are distinctive malignant mesenchymal tumors, rather than simply PEComa variants with occasionally unpredictable behavior. Meanwhile, melanotic Xp11 neoplasm and ASPS more likely represent phenotypic variants of the same entity, which is distinct from conventional PEComa and Xp11 translocation renal cell carcinoma. Based on these important findings, melanotic Xp11 neoplasm might be reclassified into a distinctive entity together with ASPS, independent from PEComa, in future revisions of the current WHO categories of tumors of soft tissue and bone for the improved reclassification. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

RNA sequencing of Xp11 translocation-associated cancers reveals novel gene fusions and distinctive clinicopathologic correlations.

Both Xp11 translocation renal cell carcinomas and the corresponding mesenchymal neoplasms are characterized by a variety of gene fusions involving TFE3. It has been known that tumors with different gene fusions may have different clinicopathologic features; however, further in-depth investigations of subtyping Xp11 translocation-associated cancers are needed in order to explore more meaningful clinicopathologic correlations. A total of 22 unusual cases of Xp11 translocation-associated cancers were selected for the current study; 20 cases were further analyzed by RNA sequencing to explore their TFE3 gene fusion partners. RNA sequencing identified 17 of 20 cases (85%) with TFE3-associated gene fusions, including 4 ASPSCR1/ASPL-TFE3, 3 PRCC-TFE3, 3 SFPQ/PSF-TFE3, 1 NONO-TFE3, 4 MED15-TFE3, 1 MATR3-TFE3, and 1 FUBP1-TFE3. The results have been verified by fusion fluorescence in situ hybridization (FISH) assays or reverse transcriptase polymerase chain reaction (RT-PCR). The remaining 2 cases with specific pathologic features highly suggestive of MED15-TFE3 renal cell carcinoma were identified by fusion FISH assay. We provide the detailed morphologic and immunophenotypic description of the MED15-TFE3 renal cell carcinomas, which frequently demonstrate extensively cystic architecture, similar to multilocular cystic renal neoplasm of low malignant potential, and expressed cathepsin K and melanotic biomarker Melan A. This is the first time to correlate the MED15-TFE3 renal cell carcinoma with specific clinicopathologic features. We also report the first case of the corresponding mesenchymal neoplasm with MED15-TFE3 gene fusion. Additional novel TFE3 gene fusion partners, MATR3 and FUBP1, were identified. Cases with ASPSCR1-TFE3, SFPQ-TFE3, PRCC-TFE3, and NONO-TFE3 gene fusion showed a wide variability in morphologic features, including invasive tubulopapillary pattern simulating collecting duct carcinoma, extensive calcification and ossification, and overlapping and high columnar cells with nuclear grooves mimicking tall cell variant of papillary thyroid carcinoma. Furthermore, we respectively evaluated the ability of TFE3 immunohistochemistry, TFE3 FISH, RT-PCR, and RNA sequencing to subclassify Xp11 translocation-associated cancers. In summary, our study expands the list of TFE3 gene fusion partners and the clinicopathologic features of Xp11 translocation-associated cancers, and highlights the importance of subtyping Xp11 translocation-associated cancers combining morphology, immunohistochemistry, and multiple molecular techniques.

Novel gene fusion of PRCC-MITF defines a new member of MiT family translocation renal cell carcinoma: clinicopathological analysis and detection of the gene fusion by RNA sequencing and FISH.

AIMS: MITF, TFE3, TFEB and TFEC belong to the same microphthalmia-associated transcription factor family (MiT). Two transcription factors in this family have been identified in two unusual types of renal cell carcinoma (RCC): Xp11 translocation RCC harbouring TFE3 gene fusions and t(6;11) RCC harbouring a MALAT1-TFEB gene fusion. The 2016 World Health Organisation classification of renal neoplasia grouped these two neoplasms together under the category of MiT family translocation RCC. RCCs associated with the other two MiT family members, MITF and TFEC, have rarely been reported. Herein, we identify a case of MITF translocation RCC with the novel PRCC-MITF gene fusion by RNA sequencing. METHODS AND RESULTS: Histological examination of the present tumour showed typical features of MiT family translocation RCCs, overlapping with Xp11 translocation RCC and t(6;11) RCC. However, this tumour showed negative results in TFE3 and TFEB immunochemistry and split fluorescence in-situ hybridisation (FISH) assays. The other MiT family members, MITF and TFEC, were tested further immunochemically and also showed negative results. RNA sequencing and reverse transcription-polymerase chain reaction confirmed the presence of a PRCC-MITF gene fusion: a fusion of PRCC exon 5 to MITF exon 4. We then developed FISH assays covering MITF break-apart probes and PRCC-MITF fusion probes to detect the MITF gene rearrangement. CONCLUSIONS: This study both proves the recurring existence of MITF translocation RCC and expands the genotype spectrum of MiT family translocation RCCs.

The Complete Mitochondrial Genome of the Longhorn Beetle Dorysthenes paradoxus (Coleoptera: Cerambycidae: Prionini) and the Implication for the Phylogenetic Relationships of the Cerambycidae Species.

The longhorn beetle Dorysthenes paradoxus (Faldermann, 1833) (Coleoptera: Cerambycidae) is not only a serious agricultural pest but also a traditionally edible insect in China. However, no genetic information on this species has been acquired. In the present study, we report the mitochondrial genome (mitogenome) of Do. paradoxus, as the first complete mitogenome of Prioninae. The circular mitogenome of 15,922 bp encodes 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), and two ribosomal RNAs (rRNAs), and it contains an A+T-rich region. This mitogenome exhibits the lowest A+T content (71.13%) but harbors the largest AT skew (0.116) among the completely sequenced Cerambycidae species. Eleven of the 13 PCGs have a typical ATN start codon, whereas COI and ND1 are tentatively designated by AAT and TTG, respectively. Only 4 of the 13 PCGs harbor a complete termination codon, and the remaining 9 possess incomplete termination codons (T or TA). Apart from tRNASer(AGN), the other 21 tRNAs can fold into a typical clover-leaf secondary structures. The Do. paradoxus A+T-rich region contains two poly-T stretches and a tandem repeat that comprises two 47-bp-long copies. Both Bayesian inference and Maximum likelihood analyses confirmed the subfamily ranks of Cerambycidae ([Prioninae + Cerambycinae] + Lamiinae) and the close relationship between Philinae and Prioninae/Cerambycinae. However, the data did not support the monophyly of Prioninae and Cerambycinae. The mitogenome presented here provides basic genetic information for this economically important species.

Frequent co-inactivation of the SWI/SNF subunits SMARCB1, SMARCA2 and PBRM1 in malignant rhabdoid tumours.

AIMS: Malignant rhabdoid tumours (MRTs) are highly aggressive malignancies of early infancy characterized by inactivation of SMARCB1, a core member of the SWI/SNF chromatin-remodelling complex. The aim of this study was to explore the status of multiple key subunits of the SWI/SNF complex in MRTs. METHODS AND RESULTS: We screened the key subunits of the SWI/SNF complex, including SMARCB1, SMARCA2, PBRM1, SMARCA4, and ARID1A, in four MRTs by immunohistochemistry, sequencing, and fluorescence in-situ hybridization (FISH). Complete loss of SMARCB1, SMARCA2 and PBRM1 expression and corresponding mutations in the same genes were observed in all cases. The mutations included seven missense, three same-sense, four frameshift and two truncating mutations. FISH revealed heterozygous deletion of SMARCB1 in one case, and monoploidy of chromosome 22, which harbours SMARCB1, in another case. Furthermore, trisomy of chromosome 9, which harbours SMARCA2, was observed in two cases. Abnormality of PBRM1 was not found in any case. CONCLUSIONS: We report, for the first time, co-inactivation and frequent mutations of SMARCB1, SMARCA2 and PBRM1 in MRTs. Multiple subunit abnormalities of the SWI/SNF complex potentially act together to contribute to the tumorigenesis of MRTs, which provides unique insights into this disease.

[Clinicopathologic study of primary renal hemangioblastoma].

OBJECTIVE: To study the clinicopathologic characteristics of primary renal hemangioblastoma. METHODS: The morphologic features, immunophenotype and molecular findings of 3 cases of primary renal hemangioblastoma were studied, with review of literature. RESULTS: The age of patients ranged from 43 to 57 years. There were 2 women and a man. The patients often presented with renal mass. Histologically, the tumors were surrounded by thick fibrous capsule and composed of epithelioid or spindle cells. Two cases had a prominent stromal component and the other one was rich in capillary network. Lipid vacuoles were observed in all cases. Features of hemorrhage were demonstrated in 2 cases. Capsular invasion and necrosis were seen in 1 case. Immunohistochemical study showed that the stromal cells were positive for alpha-inhibin (3/3), S-100 protein (3/3), EGFR (2/2), PAX-2 (2/2), PAX-8 (2/2) and CA9 (2/2) but negative for CKpan (2/2) and HMB45 (2/2). Focal membranous staining for CD10 (3/3) was noted. No VHL gene mutations or chromosome 3p deletion were detected in the 2 cases studied. CONCLUSIONS: Renal hemangioblastoma shows distinctive morphologic appearance with a wide range of variation. The unexpected positive staining for PAX-2, PAX-8 and CD10 in renal hemangioblastoma needs to be aware. Immunohistochemical study may be helpful in differential diagnosis of these renal tumors.

Loss of BRM expression is a frequently observed event in poorly differentiated clear cell renal cell carcinoma.

AIMS: The aim of this study was to examine the status of Brahma (BRM), a key SWI/SNF complex subunit, in clear cell renal cell carcinomas (RCCs), and to analyse the histopathology, immunophenotype, molecular features and prognosis of the BRM-negative cases. METHODS AND RESULTS: We identified 19 cases of grade 4 tumours lacking BRM expression among 625 clear cell RCCs. All 19 cases exhibited features of poor differentiation: 13 showed pure poorly differentiated morphology, while six were composite tumours with an admixed typical low-grade component. Besides negative BRM expression, the immunophenotype of these cases was similar to clear cell RCC. VHL gene mutations were identified in nine of the 19 patients (47%). Chromosome 3p deletion was detected in 11 of 13 poorly differentiated RCCs and both areas of five of five composite tumours. All poorly differentiated tumour areas showed polysomy of chromosome 3. No losses or gains of chromosome 3 were observed in low-grade tumour areas of five of five composite RCCs. CONCLUSIONS: We have shown that loss of BRM expression is a common feature among poorly differentiated tumours in clear cell RCCs. We hypothesize that loss of BRM expression is involved in tumor de-differentiation in clear cell RCCs and may play an important role during tumour progression.

[Clinicopathologic features of extrapulmonary inflammatory myofibroblastic tumor].

OBJECTIVE: To investigate the clinicopathologic features, immunohistochemic phenotypes and genetic alterations of extrapulmonary inflammatory myofibroblastic tumor (IMT) and the correlation with prognosis. METHODS: Thirty cases of IMT with follow-up were analyzed morphologically and immunohistochemically. ALK FISH was also performed to determine the ALK gene status. RESULTS: Patients ranged in age from 12 to 73 years (mean 43.4 years). The male-to-female ratio was 1.0: 1.1. The tumors were located in various anatomical sites including gastrointestinal tract, liver, spleen, kidney, pelvic, retroperitoneum, mediastinum etc. Histologically, the majority of cases were composed of spindled fibroblastic and myofibroblastic cells accompanied by an inflammatory infiltrate of plasma cells, lymphocytes, and eosinophils. Most cases with aggressive behavior had features including prominent nucleoli and edematous myxoid background. Lymphohistiocytic reactions were usually absent. Some cases showed multinucleation, nuclear pleomorphism and mitoses. One case demonstrated epithelioid morphology with round-to-epithelioid cells. The immunohistochemical study showed vimentin, SMA, CK, desmin, and ALK were expressed in 100% (30/30), 70% (21/30), 13% (4/30), 27% (8/30), and 27% (8/30) of IMT, respectively. Diffuse cytoplasmic ALK staining was detected in seven cases. One case (containing round-to-epithelioid cells) demonstrated ALK nuclear membrane staining, coupled with positive reaction for CD30 and negative reaction for LCA. EMA, CD34, CD117 and S-100 protein, and MyoD1 were negative for all cases. Six ALK protein positive cases harbored ALK gene rearrangement, but not the remaining 22 cases. Follow-up data were available in 21 patients. After initial resection, 14 patients were alive with no evidence of disease, while 4 patients were alive with tumor recurrence and 3 patients died of the disease. CONCLUSIONS: Most IMT with aggressive behavior have features including prominent nucleoli, edematous myxoid background, and positive expression of ALK. Lymphohistiocytic reaction is usually absent. ALK may be a potential novel therapeutic target for IMT.

[Molecular genetics and immunophenotype of INI1/SMARCB in epithelioid sarcoma].

OBJECTIVE: To study the immunophenotype and molecular genetics of epithelioid sarcoma (ES), INI1 expression and its role in differential diagnosis. METHODS: Twenty cases of ES were retrieved from the archival files and selected for immunohistochemical study, DNA sequencing and fluorescence in-situ hybridization. The clinical and pathologic features were also reviewed. RESULTS: The age of patients ranged from 16 to 75 years (mean = 40.2 years). The median age of patients in classic ES and proximal-type was 37.9 years and 42.0 years, respectively. The male-to-female ratio was 1.2: 1.0. Classic ES mostly occurred in the extremities while proximal-type ES often affected the perineum and external genitalia and trunk. Histologically, granuloma-like structures, consisting of aggregates of epithelioid and spindly tumor cells with central necrosis, were observed in classic ES. The epithelioid tumor cells contained abundant eosinophilic cytoplasm, merged with spindly cells at the periphery and admixed with collagen fibers. In proximal-type ES, the tumor cells showed prominent epithelioid and/or rhabdoid features, had marked cytologic atypia and grew in multinodular or diffuse patterns. In 2 cases of proximal-type ES studied, the "rhabdoid" tumor cells demonstrated a diffuse sheet-like growth pattern, mimicking malignant rhabdoid tumor. Immunohistochemical study showed that vimentin was positive in all cases. Pan-cytokeratin, CK8, CK7, epithelial membrane antigen and CD34 were expressed in 16, 15, 1, 18 and 13 cases, respectively. The staining for S-100 protein was focal and weak in 5 cases. None of the cases studied expressed CD31 and HMB45. Loss of INI1 was demonstrated in 10 of the 13 classic ES cases and 5 of the 7 proximal-type ES cases. The mutation of INI1 gene was detected in 1 of the 6 cases. Deletion of INI1 gene including heterozygous deletion, homozygous deletion and haploid was observed in 8 of the 11 cases. CONCLUSIONS: Owing to the histologic heterogeneity, pitfalls in diagnosis of ES sometimes are encountered. INI1 is lost in most cases of ES. Immunohistochemical study, including staining for INI1, provides useful clues in pathologic diagnosis. Instead of INI1 mutation, inactivation of INI1 gene related deletion is not uncommon.

[Clinicopathologic features of clear cell papillary renal cell carcinoma].

OBJECTIVE: To study the clinicopathological features, differential diagnosis and prognosis of clear cell papillary renal cell carcinoma (CCPRCC). METHODS: The histological, immunohistochemical, and molecular features were studied in 11 cases and follow-up data were also analyzed. RESULTS: There were a total of 3 females and 8 males. The age of patients were ranged from 33 to 72 years(mean age 52.5 years). The diameters of tumors varied from 1cm to 4 cm. Histologically, papillary and cystic architecture were present at least focally in all tumors. The papillae were covered by small to medium-sized cuboidal cells with abundant clear cytoplasm and often showed extensive secondary branching, which were often folded and densely packed, resulting in a solid appearance. The nuclei were round and uniform in shape; nucleoli were not prominent (Fuhrman grade 1 or 2). Neither mitotic figures nor necrosis was present. All 11 cases exhibited moderate to strong positivity for CK7, CA9, vimentin, and HIF-1α, coupled with negative reactions for CD10, P504S, and TFE3. Ksp-cadherin was positively expressed in 8 cases.VHL gene mutations were not found in all 11 cases. Losses of chromosomes 3 (monoploid chromosome 3) was detected in 3 cases. CONCLUSIONS: CCPRCC is uncommon and seemed to be an indolent tumor. The differential diagnosis should be included tumors, which harbor clear cell and papillary structure including clear cell renal cell carcinoma, papillary renal cell carcinoma, Xp11 translocation renal cell carcinoma, and CCPRCC. Immunohistochemical and molecular analysis may be help for its diagnosis.

[Correlation of caveolin-1 expression with clinicopathologic features and prognosis in patients with lung adenocarcinoma].

OBJECTIVE: To study the expression, clinicopathologic correlation and prognostic significance of caveolin-1 in lung adenocarcinomas(LAC). METHODS: Immunohistochemical study (EnVision method) for caveolin-1 and TTF-1 was carried out in 185 cases of LAC encountered during the period from 2005 to 2010. The correlation between caveolin-1 expression and various clinicopathologic parameters was analyzed statistically. RESULTS: The rate of caveolin-1 expression in the 185 cases of LAC was 26.5% (49/185) and significantly lower than that in normal lung tissue (P<0.01). There was also higher rate of caveolin-1 expression in male patients (P=0.004), smokers (P=0.006), tumors larger than 3.5 cm (P=0.048), predominantly solid tumor subtype (P=0.025), high tumor grade (P=0.044), tumors with vascular invasion (P=0.019), lymph node metastasis (P=0.030), recurrence (P=0.021) and high clinical stage (P=0.027). The expression level of caveolin-1 in TTF1-negative cases was significantly higher than that in TTF1-positive cases and caveolin-1 expression also negatively correlated with TTF-1 expression in LAC (r=-0.154, P=0.037). The five-year overall survival rate of patients with caveolin-1 positive tumors was lower than that in caveolin-1 negative group (P<0.01).Univariate analysis indicated the expression level of caveolin-1 and TTF-1 (P<0.01), histologic subtype (P=0.002), tumor grade (P=0.002), tumor size (P=0.009), vascular invasion (P=0.019), lymph node metastasis (P=0.018), recurrence (P=0.032) and clinical stage (P=0.024) correlated with the survival of patients with LAC. COX multivariate analysis revealed that LAC with caveolin-1 positive expression, TTF-1 negative expression and high tumor grade carried a significantly unfavorable prognosis. CONCLUSION: Caveolin-1 expression correlates with histologic subtype, tumor grade, invasiveness and metastatic potential of LAC. The detection of caveolin-1 in LAC is helpful in predicting prognosis.LAC with caveolin-1 expression carries a poor prognosis.

Recurrent Tuberous Sclerosis Complex/Mammalian Target of Rapamycin Mutations Define Primary Renal Hemangioblastoma as a Unique Entity Distinct From Its Central Nervous System Counterpart.

ABSTRACT: Renal hemangioblastoma (HB) is a rare subset of HBs arising outside of the central nervous system (CNS), with its molecular drivers remaining entirely unknown. There were no significant alterations detected in previous studies, including von Hippel-Lindau gene alterations, which are commonly associated with CNS-HB. This study aimed to determine the real molecular identity of renal HB and better understand its relationship with CNS-HB. A cohort of 10 renal HBs was submitted for next-generation sequencing technology. As a control, 5 classic CNS-HBs were similarly analyzed. Based on the molecular results, glycoprotein nonmetastatic B (GPNMB) immunohistochemistry was further performed in the cases of renal HB and CNS-HB. Mutational analysis demonstrated that all 10 renal HBs harbored somatic mutations in tuberous sclerosis complex 1 ( TSC1 , 5 cases), TSC2 (3 cases), and mammalian target of rapamycin (2 cases), with the majority classified as pathogenic or likely pathogenic. The CNS-HB cohort uniformly demonstrated somatic mutations in the von Hippel-Lindau gene. GPNMB was strong and diffuse in all 10 renal HBs and completely negative in CNS-HBs, reinforcing the molecular findings. Our study reveals a specific molecular hallmark in renal HB, characterized by recurrent TSC/mammalian target of rapamycin mutations, which defines it as a unique entity distinct from CNS-HB. This molecular finding potentially expands the therapeutic options for patients with renal HB. GPNMB can be considered for inclusion in immunohistochemical panels to improve renal HB identification.

Cathepsin K expression in a wide spectrum of perivascular epithelioid cell neoplasms (PEComas): a clinicopathological study emphasizing extrarenal PEComas.

AIMS: Recent studies have demonstrated that cathepsin K seems to be a powerful marker in identifying renal perivascular epithelioid cell neoplasms (PEComas). However, the expression in extrarenal PEComas has not been well characterized due to their rare incidence. Our aim was to investigate the expression of cathepsin K in a wide spectrum of extrarenal PEComas and evaluate its potential diagnostic usefulness in comparison with other commonly used markers. METHODS AND RESULTS: Twenty-three cases of PEComa (liver, n = 9; lung, n = 1; broad ligament of uterus, n = 1; vertex subcutaneous soft tissue, n = 1; abdominal wall, n = 1; and kidney, n = 10) were selected for study. All displayed a high percentage of cells with moderately to strongly positive reactions for cathepsin K (mean 91%; range 80-100%). HMB45, Melan-A and smooth muscle actin (SMA) were expressed in 78, 87 and 87% of cases, respectively, with various percentages of positive cells (mean, 34, 40 and 38%; range 0-80, 0-90 and 0-90%). Transcription factor E3 (TFE3) was expressed strongly in only three cases; none exhibited evidence of TFE3 gene fusion or amplification. CONCLUSIONS: Cathepsin K appears to be more powerful than other commonly used markers in diagnosing a wide spectrum of PEComas and distinguishing them from the majority of human cancers.

[Pigmented dermatofibrosarcoma protuberance: a clinicopathologic analysis of 7 cases].

OBJECTIVE: To investigate the clinical pathological features, diagnosis and differential diagnosis of pigmented dermatofibrosarcoma protuberance (PDFSP). METHODS: The clinical history, histopathological features, immunohistochemical characteristics, treatment and prognosis were analyzed in seven cases of PDFSP. Fluorescence in situ hybridization (FISH) was used to detect the expression of COL1A1/PDGFB fusion gene, and related literature was reviewed. RESULTS: The median age of the seven patients (4 females, 3 males) was 47 years with the tumors involving mostly the trunk (four cases). Histologically, PDFSP showed a cellular lesion composed of spindle cells arranged in short fascicles that form a distinct storiform pattern, and the pigmented bipolar or multipolar dendritic cells were present with tentacle like processes emanating from a nucleus containing zone. One case showed fibrosarcomatous change. The pigment was tinctorially similar to melanin. The spindle cells were positive for CD34 and vimentin, but negative for HMB45, Melan A, S-100, desmin, CD68 or α-SMA. HMB45, Melan A, S-100 and vimentin were expressed in the melanin containing cells in 4, 4, 5 and 7 cases, respectively. The labeling index of Ki-67 was 1%-8%. Among the 4 cases successfully examined by FISH, 3 showed t(17;22)(q21;q13) which suggested COL1A1/PDGFB fusion gene. Three patients were treated by wide local excision and four were treated by simple surgical excision. Two patients developed recurrences during the follow-up period of 12 to 123 months. Of those treated by wide local excision, none developed recurrence. No patient died in the follow-up period. CONCLUSIONS: PDFSP is a rare pigmented variant of DFSP and an intermediate grade malignant tumor. The orgin of the tumor cells is still controversial. Surgical pathologists and dermatopathologists need to be aware of the prototypical histological appearance of PDFSP as there is a risk of misdiagonsing it as either pigmented tumors associated with neurocutaneous syndromes or a highly malignant melanocytic neoplasm.

[Clinicopathological features of colorectal neuroendocrine neoplasms and prognostic significance of WHO staging system].

OBJECTIVE: To investigate the clinicopathological characteristics of colorectal neuroendocrine neoplasms (NENs) and the prognostic significance of the new WHO classification and staging system about gastroenteropancreatic NENs. METHODS: The clinical and pathological records were reviewed in 73 patients with colorectal NENs (carcinoids). All slides were retrieved and reviewed, immunohistochemical staining (EnVision method) was performed and follow-up information retrieved. RESULTS: Forty-one men and thirty-two women were included with a median age of 53 years (19 - 79 years). The location of the primary tumors in 65 patients was within 10 cm from the anorectal line. In 45 cases, the tumor diameter was ≤ 1 cm (no metastasis occurred); in 11 cases, the tumor diameter was > 1 cm but ≤ 2 cm (two patients had metastatic tumors); in 17 cases, the tumor diameter was > 2 cm (12 patients had metastatic tumors). The metastatic rate was significantly correlated with tumor size (P = 0.000). All tumors were immunoreactivity for synaptophysin and/or chromogranin A. According to the criteria of WHO classification and staging system about gastroenteropancreatic NENs, there were 65 cases of neuroendocrine tumors, including 51 cases of grade 1 (G1), 14 cases of grade 2 (G2), 4 cases of neuroendocrine carcinoma (G3) and 4 cases of mixed adenoneuroendocrine carcinoma. Following-up data showed that of the 34 patients with G1 tumor, there were no tumor-related death, but two patients showed metastases, and the remaining patients were disease free for 6 to 179 months. Of the 12 patients with G2 tumors, five developed metastasis, there were two tumor-related deaths, and the nine surviving patients were alive for 17 to 118 months. Of the four G3 patients, all developed metastasis and there were three tumor-related deaths. Of the four mixed adenoneuroendocrine carcinoma there were two tumor-related deaths. The difference of metastatic rate, tumor-related mortality, and overall survival among different grading groups in this series was statistically significant (P = 0.000). CONCLUSIONS: Colorectal neuroendocrine neoplasm is a group of tumors with distinct prognostic difference, and most of these tumors show an indolent clinical behavior. There is a good correlation between the new WHO classification and staging system of gastroenteropancreatic NENs and their clinical behaviors.