A Geometric Approach for Real-Time Forward Kinematics of the General Stewart Platform.

This paper presents a geometric approach for real-time forward kinematics of the general Stewart platform, which consists of two rigid bodies connected by six general serial manipulators. By describing the rigid-body motion as exponential of twist, and taking advantage of the product of exponentials formula, a step-by-step derivation of the proposed algorithm is presented. As the algorithm naturally solves all passive joint displacements, the correctness is then verified by comparing the forward-kinematic solutions from all chains. The convergence ability and robustness of the proposed algorithm are demonstrated with large amounts of numerical simulations. In all test cases, the proposed algorithm terminates within four iterations, converging with near-quadratic speed. Finally, the proposed algorithm is also implemented on a mainstream embedded motion controller. Compared with the incremental method, the proposed algorithm is more robust, with an average execution time of 0.48 ms, meeting the requirements of most applications, such as kinematic calibration, motion simulation, and real-time control.

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.

[Primary testicular diffuse large B-cell lymphoma: A clinicopathological analysis].

OBJECTIVE: To investigate the clinicopathological features, immunophenotype and treatment of primary testicular diffuse large B-cell lymphoma (DLBCL). METHODS: We retrospectively analyzed the pathomorphological characteristics and immunohistochemical markers of 23 cases of primary testicular DLBCL as well as their clinicopathological features with a review of the relevant literature. The patients were aged 48－76 (mean 61.4) years, 82.6% over 50 years, and all clinically presented with painless progressive unilateral testicular swelling, 9 cases in the left and the other 14 in the right testis. RESULTS: Histologically, the lymphomas were composed of large atypical cells with prominent karyokinesis and diffusely infiltrated the testicular parenchyma. The neoplastic cells were positive for B-cell markers. Five of the patients were followed up for 2 to 32 months, of whom 4 survived and 1 died at 9 months. CONCLUSIONS: Primary testicular DLBCL is a rare tumor with an invasive biological behavior, mostly found in elderly males and easily misdiagnosed or missed in diagnosis. Histopathology plays a key role and immunohistochemical markers are of high value in the definite diagnosis and differential diagnosis of the tumor.

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.

Xp11.2 translocation renal cell carcinoma with NONO-TFE3 gene fusion: morphology, prognosis, and potential pitfall in detecting TFE3 gene rearrangement.

Xp11 translocation renal cell carcinomas are characterized by several different translocations involving the TFE3 gene. Tumors with different specific gene fusions may have different clinicopathological manifestations. Fewer than 10 renal cell carcinoma cases with NONO-TFE3 have been described. Here we examined eight additional cases of this rare tumor using clinicopathological, immunohistochemical, and molecular analyses. The male-to-female ratio of our study cohort was 1:1, and the median age was 30 years. The most distinctive feature of the tumors was that they exhibited glandular/tubular or papillary architecture that was lined with small-to-medium cuboidal to high columnar cells with indistinct cell borders and an abundantly clear or flocculent eosinophilic cytoplasm. The nuclei were oriented toward the luminal surface and were round and uniform in shape, which resulted in the appearance of secretory endometrioid subnuclear vacuolization. The distinct glandular/tubular or papillary architecture was often accompanied by sheets of epithelial cells that presented a biphasic pattern. Immunohistochemically, all eight cases demonstrated moderate (2+) or strong (3+) positive staining for TFE3, CD10, RCC marker, and PAX-8. None of the tumors were immunoreactive for CK7, Cathepsin K, Melan-A, HMB45, Ksp-cadherin, Vimentin, CA9, 34ßE12 or CD117. NONO-TFE3 fusion transcripts were identified in six cases by RT-PCR. All eight cases showed equivocal split signals with a distance of nearly 2 signal diameters and sometimes had false-negative results. Furthermore, we developed a fluorescence in situ hybridization (FISH) assay to serve as an adjunct diagnostic tool for the detection of the NONO-TFE3 fusion gene and used this method to detect the fusion gene in all eight cases. Long-term follow-up (range, 10-102 months) was available for 7 patients. All 7 patients were alive with no evidence of recurrent disease or disease progression after their initial resection. This report adds to the known data regarding NONO-TFE3 renal cell carcinoma.

BRM/SMARCA2-negative clear cell renal cell carcinoma is associated with a high percentage of BRM somatic mutations, deletions and promoter methylation.

AIMS: The aim of this study was to investigate potential molecular mechanisms associated with loss of BRM expression in poorly differentiated clear cell renal cell carcinoma (ccRCC). METHODS AND RESULTS: Nineteen previously selected BRM-negative RCC tissues were examined by DNA sequencing, fluorescence in-situ hybridization (FISH) and methylation-specific polymerase chain reaction (PCR) of the BRM gene. BRM mutation was identified in 78.9% (15 of 19) cases, chromosome 9 monosomy or BRM deletion in 43.8% (seven of 16) and BRM promoter region cytosine-phosphate-guanine (CpG) methylation in 42.8% (six of 14). These results indicated that 89.5% (17 of 19) of the cases harboured at least one type of BRM genetic alteration, with two or more types of alteration in 47.4% (nine of 19). Such alterations were found rarely in adjacent non-neoplastic tissues and low-grade areas of composite tumours. CONCLUSIONS: BRM gene mutation, chromosome 9 monosomy or BRM deletion and CpG methylation contribute collectively to the loss of BRM expression in ccRCC. This work focusing on composite tumours indicated that BRM abnormality occurred during tumour progression.

Xp11 neoplasm with melanocytic differentiation of the prostate harbouring the novel NONO-TFE3 gene fusion: report of a unique case expanding the gene fusion spectrum.

Recently, an increasing number of TFE3 rearrangement-associated tumours have been reported, such as TFE3 rearrangement-associated perivascular epithelioid cell tumours (PEComas), melanotic Xp11 translocation renal cancers and melanotic Xp11 neoplasms. We have suggested that these tumours belong to a single clinicopathological spectrum. 'Xp11 neoplasm with melanocytic differentiation' or 'melanotic Xp11 neoplasm' have been proposed to designate this unique neoplasm. Herein, we describe the first case of an Xp11 neoplasm with melanocytic differentiation to be described in the prostate, bearing the novel NONO-TFE3 gene fusion. This study both adds to the spectrum regarding melanotic Xp11 neoplasms and expands its gene fusion spectrum. Moreover, we discuss the relationship of these rare tumours to neoplasms such as conventional PEComas, alveolar soft part sarcomas, malignant melanomas, clear cell sarcomas and Xp11 translocation renal cancers.

DCN deficiency promotes renal cell carcinoma growth and metastasis through downregulation of P21 and E-cadherin.

Decorin (DCN), as an important component of the extracellular matrix (ECM), is a small leucine-rich proteoglycan and synthesized by fibroblasts. Although DCN is dysregulated in numerous cancer types, limited data are available on the expression level and important role of DCN proteins in renal cell carcinoma (RCC). In our study, we examined the expression patterns of DCN messenger RNA (mRNA) in RCCs through the Oncomine database and DCN protein in 94 RCC specimens by immunohistochemistry (IHC). The results revealed that DCN expression was decreased in cancerous tissues compared to adjacent noncancerous tissues and was highly correlated to tumor size. Then, via gain-of-function analyses, DCN overexpression could inhibit RCC cell proliferation and metastasis in vitro and vivo. At the mechanism level, we found that an ectopic expression of DCN significantly upregulated P21 and E-cadherin expression. Altogether, these results revealed that DCN is a tumor suppressor in RCC, and it could serve as a potential therapeutic target in patients with RCC.

[Diagnostic value of immunohistochemistry and FISH for chromosome 12p in type â ¡ testicular germ cell tumors].

OBJECTIVE: To study the pathological morphology, immunohistochemical characteristics, and molecular changes of type Ⅱ testicular germ cell tumors (TGCT) and investigate the possible value of immunohistochemistry and fluorescence in situ hybridization (FISH) in the diagnosis of TGCT. METHODS: We collected for this study 97 cases of TGCT, including 75 cases of seminoma, 17 cases of embryonal carcinoma, 11 cases of yolk sac tumor, 16 cases of mature teratoma, 3 cases of immature teratoma, and 1 case of epidermoid cyst, in which normal testicular tissue was found in 20 and non-TGCT in 6. We detected the expressions of different antibodies in various subtypes of TGCT by immunohistochemistry and determined the rate of chromosome 12p abnormality using FISH. RESULTS: The immunophenotypes varied with different subtypes of TGCT. SALL4 and PLAP exhibited high sensitivity in all histological subtypes. CD117 and OCT4 showed strongly positive expressions in invasive seminoma and germ cell neoplasia in situ (GCNIS) but not in normal seminiferous tubules. GPC3 was significantly expressed in the yolk sac tumor, superior to GATA3 and AFP in both range and intensity. CKpan, OCT4, and CD30 were extensively expressed in embryonal carcinoma, while HCG expressed in choriocarcinoma. The positivity rate of isochromosome 12p and 12p amplification in TGCT was 96.7% (29/30). CONCLUSIONS: The majority of TGCT can be diagnosed by histological observation, but immunohistochemical staining is crucial for more accurate subtypes and valuable for selection of individualized treatment options and evaluation of prognosis. Chromosome 12p abnormality is a specific molecular alteration in type Ⅱ TGCT, which is useful for ruling out other lesions.

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.

[Renal cell carcinoma with t(6;11)(p21.2;q13)/MALAT1-TFEB fusion: a clinical and pathological analysis].

OBJECTIVE: To study the clinicopathologic features, immunophenotype, differential diagnosis and prognosis of renal cell carcinoma (RCC) associated with t(6;11)(p21.2;q13)/MALAT1-TFEB gene fusion. METHODS: A total of 9 cases of such rare tumor were selected for clinicopathologic, immunohistochemical and molecular analysis, with review of literature. RESULTS: The age of the patients ranged from 21 to 42 years (mean=31.3 years). The patients included four men and five women. Histologically, 4 of the 9 cases studied showed classic morphologic features of TFEB RCC, with hyaline material, pigments and psammoma bodies frequently identified. The remaining 5 cases demonstrated uncommon morphology, mimicking perivascular epithelioid cell neoplasm, clear cell RCC, chromophobe RCC or papillary RCC. Immunohistochemical study showed that TFEB and vimentin were positive in all cases. Most of the tumors studied also expressed Ksp-cadherin, E-cadherin, CD117, HMB45, Melan A and Cathepsin K. CKpan showed immunostaining in only 1 case. The staining for TFE3, CD10 and CK7 were all negative. TFEB gene rearrangement was detected in all the 9 cases studied using fluorescence in-situ hybridization. MALAT1-TFEB fusion gene was identified in 2 cases by polymerase chain reaction and direct sequencing. TFEB RCC seemed to be an indolent tumor. During a mean follow-up of 31 months, none developed tumor recurrence, progression, or metastasis. CONCLUSIONS: TFEB fusion-associated RCC is a rare neoplasm, tends to occur in young age group and carries an indolent behavior. Diagnosis relies on clinicopathologic findings and immunohistochemical analysis. TFEB break-apart FISH assay is a reliable tool in confirming the diagnosis.

[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.

[ALK gene fusion associated non-small cell lung cancer: automated immunostainer detection and clinicopathologic perspectives].

OBJECTIVE: To explore the automated immunostainer screening anaplastic lymphoma kinase (ALK) gene fusion non-small cell lung cancer (NSCLC) and clinicopathological characteristics of the molecular subtype lung cancers. Methods Five hundred and sixty-six cases of NSCLC were collected over a 16 month period. The test for ALK was performed by Ventana automated immunostainer with anti-ALK D5F3. The histological features, treatment and outcome of patients were assessed. Results Thirty-eight cases (6.7%, 38/566) of NSCLC showed ALK gene fusion. The frequency of ALK gene fusion was higher in male (7.1%, 25/350) than that in female (6.0%, 13/216) patients, but not achieving statistical significance (chi2 = 0.270, P = 0.604). ALK + NSCLC was more significantly more frequent in patients < or = 60 years (9.9%, 28/282) than >60 years (3.5% , 10/284) of age. Histologically, the ALK + NSCLCs were mostly adenocarcinoma (81.6%, 31/38) , among which eighteen cases were solid predominant subtype with mucin production; nine cases were acinar predominant subtype; one case was papillary predominant subtype and three cases were invasive mucinous adenocarcinoma. The ALK + non-adenocarcinoma included three cases of squamous cell carcinoma, three cases of adenosquamous carcinoma and one case of pleomorphic carcinoma. Among the ALK + NSCLC patients, the number of non/light cigarette smokers (86. 8% , 33/38) was more than that of heavy smokers. Twenty-nine cases were stages III and IV; twenty-nine cases showed lymph node metastasis; twenty cases showed metastases mostly to brain and bone; and one case showed EGFR gene mutation coexisting with ALK gene fusion. Twelve of fifteen patients received crizotinib therapy and remained stable. Conclusions NSCLC with ALK gene rearrangement shows distinctive clinical and histological features. Ventana-IHC may he a feasible and valid technique for detection of ALK rearrangement in NSCLC.

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.

[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.

[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.

[Primary testicular yolk sac tumor: clinicopathological study of 8 cases].

OBJECTIVE: To investigate the clinicopathological characteristics, diagnosis and treatment of primary testicular yolk sac tumor (YST). METHODS: We studied 8 cases of primary testicular YST by microscopy and immunohistochemistry. RESULTS: The 8 cases of primary testicular YST, including 2 consultation cases, were confirmed from 1998 to 2013, accounting for 10.7% (8/75) of all the testicular germ cell tumors diagnosed in our hospital. The patients ranged in age from 7 to 43 years, 23.9 years on average. The main clinical manifestation of the patients was painless unilateral testis swelling. Microscopically, reticular tissues, schiller-duvaI (S-D) bodies, and eosin-stain transparent bodies were seen in the tumors. One of the cases was confirmed to be simple YST, while the other 7 mixed YST. AFP was a characteristic immunophenotype marker of the tumors. CONCLUSION: Primary testicular YST is a rare malignancyr with poor prognosis. Its diagnosis depends on preoperative AFP test and postoperative pathology. Comprehensive treatment, including orchiectomy, chemotherapy, and radiotherapy, can prolong the survival of the patients.