Comparison of three validated PD-L1 immunohistochemical assays in urothelial carcinoma of the bladder: interchangeability and issues related to patient selection.

Different programmed cell death-ligand 1 (PD-L1) assays and scoring algorithms are being used in the evaluation of PD-L1 expression for the selection of patients for immunotherapy in specific settings of advanced urothelial carcinoma (UC). In this paper, we sought to investigate three approved assays (Ventana SP142 and SP263, and Dako 22C3) in UC with emphasis on implications for patient selection for atezolizumab/pembrolizumab as the first line of treatment. Tumors from 124 patients with invasive UC of the bladder were analyzed using tissue microarrays (TMA). Serial sections were stained with SP263 and SP142 on Ventana Benchmark Ultra and with 22C3 on Dako Autostainer Link 48. Stains were evaluated independently by two observers and scored using the combined positive score (CPS) and tumor infiltrating immune cells (IC) algorithms. Differences in proportions (DP), overall percent agreement (OPA), positive percent agreement (PPA), negative percent agreement (NPA), and Cohen κ were calculated for all comparable cases. Good overall concordance in analytic performance was observed for 22C3 and SP263 with both scoring algorithms; specifically, the highest OPA was observed between 22C3 and SP263 (89.6%) when using CPS. On the other hand, SP142 consistently showed lower positivity rates with high differences in proportions (DP) compared with 22C3 and SP263 with both CPS and IC, and with a low PPA, especially when using the CPS algorithm. In conclusion, 22C3 and SP263 assays show comparable analytical performance while SP142 shows divergent staining results, with important implications for the selection of patients for both pembrolizumab and atezolizumab.

TFE3 and TFEB-rearranged renal cell carcinomas: an immunohistochemical panel to differentiate from common renal cell neoplasms.

TFE3/TFEB-rearranged renal cell carcinomas are characterized by translocations involving TFE3 and TFEB genes. Despite the initial description of typical morphology, their histological spectrum is wide, mimicking common subtypes of renal cell tumors. Thus, the diagnosis is challenging requiring the demonstration of the gene rearrangement, usually by FISH. However, this technique is limited in most laboratories and immunohistochemical TFE3/TFEB analysis is inconsistent. We sought to identify a useful immunohistochemical panel using the most common available markers to recognize those tumors. We performed an immunohistochemical panel comparing 27 TFE3-rearranged and 10 TFEB-rearranged renal cell carcinomas to the most common renal cell tumors (150 clear cell, 100 papillary, 50 chromophobe renal cell carcinomas, 18 clear cell papillary renal cell tumors, and 50 oncocytomas). When dealing with neoplasms characterized by cells with clear cytoplasm, CA9 is a helpful marker to exclude clear cell renal cell carcinoma. GATA3, AMACR, and CK7 are useful to rule out clear cell papillary renal cell tumor. CK7 is negative in TFE3/TFEB-rearranged renal cell carcinoma and positive in papillary renal cell carcinoma, being therefore useful in this setting. Parvalbumin and CK7/S100A1 respectively are of paramount importance when TFE3/TFEB-rearranged renal cell carcinoma resembles oncocytoma and chromophobe renal cell carcinoma. Moreover, in TFEB-rearranged renal cell carcinoma, cathepsin K and melanogenesis markers are constantly positive, whereas TFE3-rearranged renal cell carcinoma stains for cathepsin K in roughly half of the cases, HMB45 in 8% and Melan-A in 22%. In conclusion, since TFE3/TFEB-rearranged renal cell carcinoma may mimic several histotypes, an immunohistochemical panel to differentiate them from common renal cell tumors should include cathepsin K, CA9, CK7, and parvalbumin.

TSC loss is a clonal event in eosinophilic solid and cystic renal cell carcinoma: a multiregional tumor sampling study.

Eosinophilic, solid and cystic (ESC) renal cell carcinoma (RCC) is characterized by a solid and cystic architecture with cells showing abundant eosinophilic cytoplasm with hobnail arrangement and a cytokeratin 7-negative/cytokeratin 20-positive immunophenotype. Recent studies have suggested that bi-allelic events affecting TSC genes might play an important role for such tumors. However, only indirect evidence of the clonal origin of TSC mutation has been gathered so far. Therefore, in this paper we aimed to perform multi-regional tumor sampling molecular analysis in four ESC RCC cases that had been completely embedded, three sporadic and one occurring in a patient with tuberous sclerosis complex (TSC). Histologically, the 4 cases showed cystic and solid architecture and cells with abundant eosinophilic cytoplasm with cytoplasmic stippling and round to oval nuclei. Immunohistochemistry showed at least focal expression of cytokeratin 20 in all tissue samples and negative cytokeratin 7, as well as diffuse positivity for S100A1 and at least focal expression of cathepsin K in three out of four cases. The sporadic cases showed the same somatic TSC1 mutations in all tissue samples analyzed, while the TSC-associated case showed the same TSC1 alteration in both normal tissue and all tumor samples analyzed, proving the germline nature of the alteration. In conclusion, our data demonstrate that clonal TSC loss is a key event in ESC RCC and support considering ESC RCC as an entity given its distinct morphologic, immunophenotypical and molecular characteristics.

Stimulator of interferon genes (STING) immunohistochemical expression in the spectrum of perivascular epithelioid cell (PEC) lesions of the kidney.

Angiomyolipoma is the prototype of renal perivascular epithelioid cell (PEC) lesions whose pathogenesis is determined by mutations affecting TSC genes, with eventual deregulation of the mTOR pathway. It is well known that mTOR complex protein is involved in autophagy, and recently the role of STING in this process has been demonstrated. Based on this background, we sought to investigate STING immunohistochemical expression in a series of PEC lesions of the kidney. Fifty classic angiomyolipomas, 14 epithelioid angiomyolipomas/pure epithelioid PEComas, two angiomyolipomas with epithelial cysts (AMLEC), and two intraglomerular PEC lesions were collected. Immunostaining for STING was carried out in all cases and FISH analysis using dual colour break apart TFE3 and TFEB probes was performed in all pure epithelioid PEComas and AMLEC. Control cases including 20 normal adult kidneys, five fetal kidneys, and 30 MiT family translocation renal cell carcinomas (the main differential diagnosis with epithelioid angiomyolipoma/pure epithelioid PEComa) were also immunohistochemically stained with STING. Strong and diffuse cytoplasmic expression of STING was observed in 100% of classic angiomyolipomas, AMLEC, and intraglomerular lesions, and in 79% (11/14) of epithelioid angiomyolipomas/pure epithelioid PEComas. TFE3 gene rearrangement was demonstrated in two epithelioid angiomyolipomas/pure epithelioid PEComas, both completely negative for STING. None of the MiT family translocation renal cell carcinomas expressed STING. In conclusion, we demonstrate the expression of STING in almost all PEC lesions of the kidney. This result provides novel insights into the possible role of autophagy in PEC lesions of the kidney. Moreover, this finding may be useful for diagnostic purposes, particularly in distinguishing epithelioid angiomyolipoma/pure epithelioid PEComa from MiT family translocation renal cell carcinoma and detecting intraglomerular PEC lesions.

Report of two primary renal tumors with myxoid features. Differential diagnosis between benign and malignant entities.

Renal mesenchymal neoplasms are rare entities which can have a benign or a malignant behavior. Herein we describe two renal mesenchymal tumors with myxoid stroma, investigating the wide spectrum of differential diagnosis. With our first case we considered some benign entities such as myxoma, myxoid leiomyoma, and mixed epithelial and stromal tumor; with our second case we considered some sarcomas with myxoid features such as myxofibrosarcoma, low-grade fibromyxoid sarcoma, dedifferentiated liposarcoma, and myxoid liposarcoma. During the diagnostic process, it is important to integrate histopathological, immunohistochemical, and molecular data in order to avoid misdiagnosis. We concluded our second case report was a myxofibrosarcoma grade 1. To the best of our knowledge, we described the fourth primary renal myxofibrosarcoma reported in literature.

TFEB rearranged renal cell carcinoma. A clinicopathologic and molecular study of 13 cases. Tumors harboring MALAT1-TFEB, ACTB-TFEB, and the novel NEAT1-TFEB translocations constantly express PDL1.

Renal cell carcinomas with t(6;11) chromosome translocation has been classically characterized by the rearrangement of the TFEB gene, located on chromosome 6, and MALAT1 gene, located on chromosome 11. Recently, a few other genes have been described as fusion partners in TFEB rearranged renal cell carcinomas. Although most of TFEB rearranged renal cell carcinomas have an indolent behavior, in the rare cases of advanced metastatic disease targeted therapy and predictive markers remain lacking. In the present study, we collected 13 TFEB rearranged renal cell carcinomas, confirmed by FISH, analyzing their morphology and exploring the novel gene partners. Looking for predictive markers, we have also performed PDL1 immunohistochemical analysis by using four different assays (E1L3N, 22C3, SP142, and SP263). MALAT1 gene rearrangement has been found in ten tumors, five cases showing classical biphasic morphology with "rosettes", five cases without "rosettes" mimicking other renal cell carcinomas or epithelioid angiomyolipoma/pure epithelioid PEComa. We identified two different partner genes, ACTB and NEAT1, the latter previously unreported and occurring in a tumor with an unusual solid and cystic appearance. In both cases, the "rosettes" were absent. In one case no gene partner was identified. Overall, in 12 of 13 TFEB-rearranged renal cell carcinomas staining for PDL1 SP263 was observed, whereas the other antibodies were less reliable or more difficult to interpret. In conclusion, we described the third case of ACTB-TFEB rearranged renal cell carcinoma and a novel NEAT1-TFEB rearranged renal cell carcinoma, both without the distinctive biphasic morphology typical of t(6;11) renal cell carcinoma. Finally, PDL1 SP263 was constantly expressed in TFEB rearranged renal cell carcinoma with possible clinical benefit which requires further investigations.

Angiomyolipoma of the kidney: from simple hamartoma to complex tumour.

Angiomyolipoma is the most common mesenchymal tumour of the kidney, even if for a long time it has been viewed as a hamartoma rather than a neoplasm. It belongs to a family of neoplasms, named PEComa, characterised by the constant presence of perivascular epithelioid cells that co-express smooth muscle and melanogenesis markers. Angiomyolipoma can occur in patients with tuberous sclerosis, a hereditary syndrome due to the alteration of TSC1 or TSC2 genes, or sporadically. Angiomyolipoma and its variants are indolent tumours; however, some epithelioid angiomyolipomas/pure epithelioid PEComas are aggressive, and criteria for malignancy have been proposed to identify those cases. Although typical angiomyolipoma is a straightforward diagnosis, pathologists should be aware of the wide morphological spectrum of its variants which could be tricky in routine clinical practice and could require immunohistochemical analysis for resolution. The differential diagnosis may range from an inflammatory process (for instance xanthogranulomatous pyelonephritis) to the most common renal cancers and sarcomas. The immunoexpression of melanogenesis markers (HMB45 and Melan-A) and cathepsin K is extremely helpful in the majority of cases. Recently, a subset of epithelioid angiomyolipoma/pure epithelioid PEComa harbouring TFE3 gene fusions has been described, raising questions about its relationship with the family of perivascular epithelioid cell tumour. The activation of the mTOR pathway due to genetic alterations of tuberous sclerosis complex in TSC1 or TSC2 genes in angiomyolipoma has also been reported as well as the subsequent therapeutic implications.

Correction to: Multi-institutional re-evaluation of prognostic factors in chromophobe renal cell carcinoma: proposal of a novel two-tiered grading scheme.

The legends of Figs. 1 and 3 in the published original version of the above article are incorrect.

Comprehensive analysis of 34 MiT family translocation renal cell carcinomas and review of the literature: investigating prognostic markers and therapy targets.

Recently cabozantinib, a tyrosine kinase inhibitor with activity against VEGF, MET, AXL, and downregulating cathepsin K in vitro, has been proposed for the treatment of advanced clear and non-clear renal cell carcinomas. Since it is well known that cathepsin K is expressed in the majority of MiT family translocation renal cell carcinomas, we investigated cathepsin K, MET, AXL, and VEGF in a large series of those tumours, looking for possible predictive markers. We collected the clinicopathological features of 34 genetically confirmed MiT family translocation renal cell carcinomas [26 Xp11 and 8 t(6;11) renal cell carcinomas] and studied them using an immunohistochemical panel including PAX8, cathepsin K, HMB45, Melan-A, CD68 (PG-M1), CK7, CA9, MET, AXL and by FISH for VEGFA and MET. Cathepsin K was expressed in 14 of 26, HMB45 in 8 of 25, and Melan-A in 4 of 23 Xp11 renal cell carcinomas, whereas labelling for CK7 and CA9 was minimal. In t(6;11) renal cell carcinoma, cathepsin K and melanogenesis markers were constantly positive, whereas CK7 and CA9 were negative. None of the 34 carcinomas showed CD68 (PG-M1) and AXL expression. One aggressive Xp11 renal cell carcinoma showed increased VEGFA gene copy number (4-5 copies) with concurrent gains of TFE3 and TFEB. None of the 34 carcinomas showed MET gene amplification, whereas staining for MET was found in 7 of 8 t(6;11) and in 16 of 24 Xp11 renal cell carcinomas, and in the latter cases, when the expression was >50%, correlated with aggressiveness (p=0.0049). In Xp11 renal cell carcinomas, the aggressiveness was also correlated with larger tumour size (p=0.0008) and the presence of necrosis (p=0.027) but not nucleolar grading (p=1). Interestingly, in patients with tumours exhibiting two of three parameters (necrosis, larger tumour size and MET immunolabelling >50%) an aggressive clinical behaviour was observed in 88% of cases. In conclusion, cathepsin K, CD68 (PG-M1), CK7, CA9, and PAX8 is a useful panel for the diagnosis. Larger tumour size, the presence of necrosis and MET immunohistochemical expression correlate with aggressive behaviour in Xp11 renal cell carcinomas, especially in combination. VEGF, MET, cathepsin K but not AXL may be potential predictive markers for targeted therapy in MiT family translocation renal cell carcinomas.

Multi-institutional re-evaluation of prognostic factors in chromophobe renal cell carcinoma: proposal of a novel two-tiered grading scheme.

A histological grading system of chromophobe renal cell carcinoma (chRCC) is highly desirable to identify approximately 5-10% of tumors at risk for progression. Validation studies failed to demonstrate a correlation between the four-tiered WHO/ISUP grade and outcome. Previous proposals with three-tiered chromophobe grading systems could not be validated. In this study, the presence of sarcomatoid differentiation, necrosis, and mitosis was analyzed in a Swiss cohort (n = 42), an Italian cohort (n = 103), a German cohort (n = 54), a Japanese cohort (n = 119), and The Cancer Genome Atlas cohort (n = 64). All 3 histological parameters were significantly associated with shorter time to tumor progression and overall survival in univariate analysis. Interobserver variability for identification of these parameters was measured by Krippendorff's alpha coefficient and showed high concordance for the identification of sarcomatoid differentiation and tumor necrosis, but only low to medium concordance for the identification of mitosis. Therefore, we tested a two-tiered tumor grading system (low versus high grade) based only on the presence of sarcomatoid differentiation and/or necrosis finding in the combined cohorts (n = 382). pT stage, patient's age (> 65 vs ≤ 65), lymph node and/or distant metastasis, and the two-tiered grading system (low versus high grade) were significantly associated with overall survival and were independent prognostic parameters in multivariate analysis (Cox proportional hazard). This multi-institutional evaluation of prognostic parameters suggests tumor necrosis and sarcomatoid differentiation as reproducible components of a two-tiered chromophobe tumor grading system.

MiT Family Translocation Renal Cell Carcinoma: from the Early Descriptions to the Current Knowledge.

The new category of MiT family translocation renal cell carcinoma has been included into the World Health Organization (WHO) classification in 2016. The MiT family translocation renal cell carcinoma comprises Xp11 translocation renal cell carcinoma harboring TFE3 gene fusions and t(6;11) renal cell carcinoma harboring TFEB gene fusion. At the beginning, they were recognized in childhood; nevertheless, it has been demonstrated that these neoplasms can occur in adults as well. In the nineties, among Xp11 renal cell carcinoma, ASPL, PRCC, and SFPQ (PSF) were the first genes recognized as partners in TFE3 rearrangement. Recently, many other genes have been identified, and a wide spectrum of morphologies has been described. For this reason, the diagnosis may be challenging based on the histology, and the differential diagnosis includes the most common renal cell neoplasms and pure epithelioid PEComa/epithelioid angiomyolipoma of the kidney. During the last decades, many efforts have been made to identify immunohistochemical markers to reach the right diagnosis. To date, staining for PAX8, cathepsin K, and melanogenesis markers are the most useful identifiers. However, the diagnosis requires the demonstration of the chromosomal rearrangement, and fluorescent in situ hybridization (FISH) is considered the gold standard. The outcome of Xp11 translocation renal cell carcinoma is highly variable, with some patients surviving decades with indolent disease and others dying rapidly of progressive disease. Despite most instances of t(6;11) renal cell carcinoma having an indolent clinical course, a few published cases demonstrate aggressive behavior. Recently, renal cell carcinomas with TFEB amplification have been described in connection with t(6;11) renal cell carcinoma. Those tumors appear to be associated with a more aggressive clinical course. For the aggressive cases of MiT family translocation carcinoma, the optimal therapy remains to be determined; however, new target therapies seem to be promising, and the search for predictive markers is mandatory.

Tamoxifen related Uterine Tumor Resembling Ovarian Sex Cord Tumor (UTROSCT): A case report and literature review of this possible association.

It is well known that a large number of patients treated with Tamoxifen develops endometrial pathologies ranging from benign endometrial polyps and hyperplasia to adenocarcinomas, carcinosarcomas and adenosarcomas. UTROSCT (Uterine Tumor Resembling Ovarian Sex Cord Tumor) is defined as a mesenchymal tumors of the uterine corpus that morphologically resembles ovarian sex cord tumors, without recognizable endometrial stroma. To date only 4 cases have been reported in patients treated with tamoxifen. In this article, we describe an additional case occurring in a 62-years-old patient undergoing 3 years of Tamoxifen therapy for bilateral breast carcinoma. The present work represents a further evidence of the possible association between Tamoxifen therapy and UTROSCT. A comprehensive literature review on this topic is also provided.

VEGFA amplification/increased gene copy number and VEGFA mRNA expression in renal cell carcinoma with TFEB gene alterations.

Amplification of vascular endothelial growth factor A (VEGFA) has been recently reported in TFEB-amplified renal cell carcinomas regardless the level of TFEB amplification. We sought to determine VEGFA amplification by fluorescent in situ hybridization (FISH) and VEGFA mRNA expression by in situ hybridization (RNAscope 2.5) in a series of 10 renal cell carcinomas with TFEB gene alterations, either amplification and/or rearrangement (t(6;11) renal cell carcinoma). TFEB gene rearrangement was demonstrated in eight cases, whereas the remaining two cases showed a high level of TFEB (> 10 copies of fluorescent signals) gene amplification without evidence of rearrangement. Among the eight t(6;11) renal cell carcinomas (TFEB-rearranged cases), one case displayed a high level of TFEB gene amplification and two showed increased TFEB gene copy number (3-4 copies of fluorescent signals). Those three cases behaved aggressively. By FISH, VEGFA was amplified in all three cases with TFEB amplification and increased VEGFA gene copy number was observed in the two aggressive cases t(6;11) renal cell carcinomas with an overlapping increased number of TFEB fluorescent signals. Overall, VEGFA mRNA expression was observed in 8 of 10 cases (80%); of these 8 cases, 3 cases showed high-level TFEB amplification, one case showed TFEB rearrangement with increased TFEB gene copy number, whereas four showed TFEB gene rearrangement without increased copy number. In summary, VEGFA amplification/increased gene copy number and VEGFA mRNA expression occur in TFEB-amplified renal cell carcinoma, but also in a subset of t(6;11) renal cell carcinoma demonstrating aggressive behavior, and in unamplified conventional t(6;11) renal cell carcinoma suggesting VEGFA as potential therapeutic target in these neoplasms even in the absence of TFEB amplification. We finally propose that all the renal tumors showing morphological characteristics suggesting t(6;11) renal cell carcinoma and all unclassified renal cell carcinomas, either high grade or low grade, should immunohistochemically be evaluated for cathepsin K and/or Melan-A and if one of them is positive, tested for TFEB gene alteration and VEGFA gene amplification.

Proximal CD13 Versus Distal GATA-3 Expression in Renal Neoplasia According to WHO 2016 Classification.

Little is known about the aminopeptidase CD13 in renal neoplasia according to the new 2016 World Health Organization renal tumor classification. We selected 175 cases, including 79 clear cell, 31 papillary, 24 chromophobe, 8 clear cell papillary renal cell carcinomas (RCCs), 21 oncoytomas, and 12 microphthalmia transcription factor family translocation RCCs: 4 t(6;11)/transcription factor EB (TFEB), 7 t(Xp11) with 2 cystic variants and 1 t(X;17). GATA binding protein 3 (GATA-3) was inserted as control. Expression of proximal antigen CD13 was observed in 63/79 (80%) clear cell, 25/31 (81%) papillary, 3/8 (37%) clear cell papillary, 1/4 (25%) t(6;11)/TFEB, 2/7 (28%) cystic t(Xp11), and in 1/1 t(X;17) RCCs. All chromophobe RCC (0/24) and all oncocytomas (0/21) resulted negative. CD10 was seen in 76/79 (96%) clear cell, 15/31 (48%) papillary, 10/24 (42%) chromophobe, 1/8 (12%) clear cell papillary RCCs, 4/21 (19%) oncocytomas, 1/4 (25%) t(6;11)/TFEB, 2/7 (29%) cystic t(Xp11), and in 1/1 t(X;17) RCCs. GATA-3 was positive in 3/7 (42%) clear cell papillary RCCs and negative in all remaining RCCs, except a single chromophobe RCC and a single oncocytoma. We concluded that: (1) CD13 and GATA-3 immunostains may serve as a diagnostic aid in differentiating subtypes of RCC; (2) CD13 is always absent in chromophobe RCC and oncocytomas, whereas CD10 can be immunoexpressed in both; (3) CD13 should be included in a panel of antibodies to distinguish "proximal renal tumors" from "distal renal tumors" and between clear cell RCC versus microphthalmia transcription factor family translocations RCCs; and (4) when present, GATA-3 is specific for clear cell papillary RCC.

t(6;11) renal cell carcinoma: a study of seven cases including two with aggressive behavior, and utility of CD68 (PG-M1) in the differential diagnosis with pure epithelioid PEComa/epithelioid angiomyolipoma.

Renal cell carcinomas with t(6;11) chromosome translocation involving the TFEB gene are indolent neoplasms which often occur in young patients. In this study, we report seven cases of renal cell carcinoma with TFEB rearrangement, two of whom had histologically proven metastasis. Patients (4F, 3M) ranged in age from 19 to 55 years (mean 37). One patient developed paratracheal and pleural metastases 24 months after surgery and died of disease after 46 months; another one recurred with neoplastic nodules in the perinephric fat and pelvic soft tissue. Histologically, either cytological or architectural appearance was peculiar in each case whereas one tumor displayed the typical biphasic morphology. By immunohistochemistry, all tumors labelled for cathepsin K, Melan-A and CD68 (KP1 clone). HMB45 and PAX8 staining were detected in six of seven tumors. All tumors were negative for CD68 (PG-M1 clone), CKAE1-AE3, CK7, CAIX, and AMACR. Seven pure epithelioid PEComa/epithelioid angiomyolipomas, used as control, were positive for cathepsin K, melanocytic markers, and CD68 (PG-M1 and KP1) and negative for PAX8. Fluorescence in situ hybridization results showed the presence of TFEB gene translocation in all t(6;11) renal cell carcinomas with a high frequency of split TFEB fluorescent signals (mean 74%). In the primary and metastatic samples of the two aggressive tumors, increased gene copy number was observed (3-5 fluorescent signals per neoplastic nuclei) with a concomitant increased number of CEP6. Review of the literature revealed older age and larger tumor size as correlating with aggressive behavior in these neoplasms. In conclusion, we present the clinical, morphological and molecular features of seven t(6;11) renal cell carcinomas, two with histologically demonstrated metastasis. We report the high frequency of split signals by FISH in tumors with t(6;11) chromosomal rearrangement and the occurrence of TFEB gene copy number gains in the aggressive cases, analyzing either the primary or metastatic tumor. Finally, we demonstrate the usefulness of CD68 (PG-M1) immunohistochemical staining in distinguishing t(6;11) renal cell carcinoma from pure epithelioid PEComa/epithelioid angiomyolipoma.

Primary seminal vesicle carcinoma. The usefulness of PAX8 immunohistochemical expression for the differential diagnosis.

Primary seminal vesicle carcinoma is a rare entity whose diagnosis can be achieved by ruling out the main carcinomas that commonly invade the seminal vesicles. Although a panel of immunohistochemical markers (cancer antigen 125, cytokeratin [CK] 7, CK20, prostate-specific antigen, and prostate-specific acid phosphatase) has been proposed as unique for primary seminal vesicle carcinoma, a reliable positive marker is lacking. In this article, we report a case of primary seminal vesicle carcinoma in a 57-year-old man. The tumor was localized to the left seminal vesicle and histologically characterized by papillae lined by broad eosinophilic cells with pleomorphic nuclei. The neoplastic cells expressed cancer antigen 125 and CK7, whereas CK20, prostate-specific antigen, and prostate-specific acid phosphatase were negative. A strong and diffuse nuclear labeling for PAX8 was detected. Because carcinomas of the colon, bladder, and prostate, the main differential diagnosis in this setting, have been reported consistently to be PAX8 negative, this marker may be very useful for a prompt diagnosis of seminal vesicle carcinoma.

Validation of 34betaE12 immunoexpression in clear cell papillary renal cell carcinoma as a sensitive biomarker.

Clear cell papillary renal cell carcinoma (CCPRCC) is a recently recognised neoplasm with a broad spectrum of morphological characteristics, thus representing a challenging differential diagnosis, especially with the low malignant potential multicystic renal cell neoplasms and clear cell renal cell carcinoma. We selected 14 cases of CCPRCC with a wide spectrum of morphological features diagnosed on morphology and CK7 immunoreactivity and analysed them using a panel of immunohistochemical markers, focusing on 34ßE12 and related CKs 1,5,10 and 14 and several molecular analyses such as fluorescence in situ hybridisation (FISH), array comparative genomic hybridisation (aCGH), VHL methylation, VHL and TCEB1 sequencing and multiplex ligation-dependent probe amplification (MLPA). Twelve of 13 (92%) CCPRCC tumours were positive for 34ßE12. One tumour without 3p alteration by FISH revealed VHL mutation and 3p deletion at aCGH; thus, it was re-classified as clear cell RCC. We concluded that: (1) immunohistochemical expression of CK7 is necessary for diagnostic purposes, but may not be sufficient to identify CCPRCC, while 34ßE12, in part due to the presence of CK14 antigen expression, can be extremely useful for the recognition of this tumour; and (2) further molecular analysis of chromosome 3p should be considered to support of CCPRCC diagnosis, when FISH analysis does not evidence the common loss of chromosome 3p.

PEComas of the kidney and of the genitourinary tract.

PEComas are mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells that are characterized by the coexpression of muscle and melanogenetic markers. This group of lesions includes angiomyolipoma, clear cell "sugar" tumor of the lung and extrapulmonary sites, lymphangioleiomyomatosis, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, and rare clear cell tumors of other anatomical sites. In the genitourinary tract, PEComas have been described in the kidney, bladder, prostate, testis, and urethra. Although most PEComas behave as benign tumors, some are potentially malignant, and criteria for malignancy have been suggested for both and renal and extrarenal lesions. Recently, the expression of cathepsin K has been demonstrated in a large number of PEComas and has been proposed as a relatively specific marker to distinguish these proliferations from the majority of human cancers. In addition, a distinctive subset of PEComas harboring TFE3 gene fusions has been reported, giving rise to a possible relationship between them and MiTF/TFE family translocation renal cell carcinomas. The genetic alterations of tuberous sclerosis complex that promote activation of the mTOR pathway have been identified in PEComas. Therapy with mTORC1 inhibitors has been shown to be effective in some cases.

Adenocarcinoma of the paraurethral glands: a case report.

Adenocarcinoma of the paraurethral glands represents a very rare neoplasm of the urinary tract. Due to the rarity of this disease, there is no standard therapeutic approach. We report a case of adenocarcinoma of the paraurethral glands in a 56-year-old woman, presenting with abnormal serous vaginal discharges. The radiologic examination revealed a 5-cm mass around the urethra, which underwent surgical resection. After surgical resection, the histology revealed a moderately differentiated adenocarcinoma, probably arising from the paraurethral glands. One month later, a pelvic recurrent mass was radiologically diagnosed; consequently, an anterior pelvic exenteration with lymph node dissection was performed. Histological examination revealed a moderately differentiated adenocarcinoma, with glandular and micropapillary architecture, with multiple lymph node metastases. The absence of modifications such as urethritis cystic glandularis on the urethral mucosa, as well as the lack of a lesion in situ, associated with the immunohistochemical expression of PAX8 and negativity for GATA3 and S100p, suggested that the adenocarcinoma originated from the paraurethral glands rather than from the urethral mucosa. Post-surgery CT scans revealed no evidence of metastatic disease. The patient received 6 courses of adjuvant chemotherapy with carboplatin and paclitaxel. One year after the pelvic exenteration, because of inguinal lymph node progression, an inguinal lymphadenectomy was performed. Four months later, a TC-PET revealed a multidistrectual lymph node and a lung micronodule disease progression. Invasive micropapillary carcinomas have been characterized as a rare distinctive variant of carcinomas in several anatomic sites and are distinguished by a marked tendency to lymphovascular invasion, justifying the association with high-stage disease and poor prognosis. In the present case, both the poor prognosis connected with micropapillary structure and the lymph node involvement, encouraged adjuvant cisplatinum-based chemotherapy.