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The Genitourinary Pathology Society (GUPS) reviewed recent advances in renal neoplasia, particularly post-2016 World Health Organization (WHO) classification, to provide an update on existing entities, including diagnostic criteria, molecular correlates, and updated nomenclature. Key prognostic features for clear cell renal cell carcinoma (RCC) remain WHO/ISUP grade, AJCC/pTNM stage, coagulative necrosis, and rhabdoid and sarcomatoid differentiation. Accrual of subclonal genetic alterations in clear cell RCC including SETD2, PBRM1, BAP1, loss of chromosome 14q and 9p are associated with variable prognosis, patterns of metastasis, and vulnerability to therapies. Recent National Comprehensive Cancer Network (NCCN) guidelines increasingly adopt immunotherapeutic agents in advanced RCC, including RCC with rhabdoid and sarcomatoid changes. Papillary RCC subtyping is no longer recommended, as WHO/ISUP grade and tumor architecture better predict outcome. New papillary RCC variants/patterns include biphasic, solid, Warthin-like, and papillary renal neoplasm with reverse polarity. For tumors with 'borderline' features between oncocytoma and chromophobe RCC, a term "oncocytic renal neoplasm of low malignant potential, not further classified" is proposed. Clear cell papillary RCC may warrant reclassification as a tumor of low malignant potential. Tubulocystic RCC should only be diagnosed when morphologically pure. MiTF family translocation RCCs exhibit varied morphologic patterns and fusion partners. TFEB-amplified RCC occurs in older patients and is associated with more aggressive behavior. Acquired cystic disease (ACD) RCC-like cysts are likely precursors of ACD-RCC. The diagnosis of renal medullary carcinoma requires a negative SMARCB1 (INI-1) expression and sickle cell trait/disease. Mucinous tubular and spindle cell carcinoma (MTSCC) can be distinguished from papillary RCC with overlapping morphology by losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22. MTSCC with adverse histologic features shows frequent CDKN2A/2B (9p) deletions. BRAF mutations unify the metanephric family of tumors. The term "fumarate hydratase deficient RCC" ("FH-deficient RCC") is preferred over "hereditary leiomyomatosis and RCC syndrome-associated RCC". A low threshold for FH, 2SC, and SDHB immunohistochemistry is recommended in difficult to classify RCCs, particularly those with eosinophilic morphology, occurring in younger patients. Current evidence does not support existence of a unique tumor subtype occurring after chemotherapy/radiation in early childhood.

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.

Tumor-infiltrating lymphocytes and immune checkpoint proteins such as PD-L1 are potential prognostic factors and therapeutic targets in breast cancer. Most studies characterizing the breast tumor immune microenvironment have focused on ductal carcinomas. Here we investigate the tumor microenvironment of primary invasive lobular carcinomas. Previously constructed tissue microarrays of 47 lobular carcinomas were labeled by immunohistochemistry for PD-L1, CD8, CD20, and FoxP3. The stromal immune infiltrate density was qualitatively scored as a percentage of tumor area: 1+ ( 50%). The average immune cell subtype per high-power field was quantitatively scored. The percentage PD-L1 labeling on tumor-infiltrating lymphocytes was scored as none, focal (

Summary Telomeres are nucleoprotein complexes located at the extreme ends of eukaryotic chromosomes and protect chromosomal ends from degradation and recombination. Dysfunctional telomeres contribute to genomic instability, promote tumorigenesis, and, in breast cancer, have been associated with increased cancer risk and poor prognosis. Short telomere lengths have been previously associated with triple-negative and human epidermal growth factor receptor (Her2)--positive ductal carcinomas. However, these investigations have not specifically assessed invasive lobular carcinomas (ILCs), which accounts for 5% to 15% of all invasive breast cancers. Here, we evaluate telomere lengths within 48 primary ILCs with complete characterization of estrogen receptor (ER), progesterone receptor (PR), and Her2 status, including 32 luminal/Her2− (ER+/PR+/Her2−), 8 luminal/Her2+ (ER+/PR+/Her2+), 3 Her2+ (ER−/PR−/Her2+), and 5 triple-negative (ER−/PR−/Her2−) carcinomas. A telomere-specific fluorescence in situ hybridization assay, which provides single-cell telomere length resolution, was used to evaluate telomere lengths and compare with standard clinicopathological markers. In contrast to breast ductal carcinoma, in which more than 85% of cases display abnormally short telomeres, approximately half (52%) of the ILCs displayed either normal or long telomeres. Short telomere length was associated with older patient age. Interestingly, 3 cases (6%) displayed a unique telomere pattern consisting of 1 or 2 bright telomere spots among the normal telomere signals within each individual cancer cell, a phenotype that has not been previously described. Additional studies are needed to further evaluate the significance of the unique bright telomere spot phenotype and the potential utility of telomere length as a prognostic marker in ILC.

We describe 6 cases of a biphasic renal neoplasm, which we designate smooth muscle and adenoma-like renal tumor, which do not cleanly fit any category as currently defined. There were 4 females and 2 males (age, 27-70 years); neither male had a history of hormone exposure. All 5 neoplasms with available history were discovered incidentally on imaging studies with sizes ranging from 4 to 20 cm. The stroma was composed of smooth muscle fascicles alternating with looser, edematous areas; none of the cases contained ovarian-like stroma. The complex but cytologically benign epithelial component consisted of tubulopapillary nodules, branching tubules, clefts, and large cysts. The stroma of all of the cases labeled diffusely for desmin. Estrogen receptor labeling was absent in 4 cases with only minimal (

The MiT subfamily of transcription factors includes TFE3, TFEB, TFC, and MiTF. Gene fusions involving two of these transcription factors have been identified in renal cell carcinoma (RCC). The Xp11 translocation RCCs were first officially recognized in the 2004 WHO renal tumor classification, and harbor gene fusions involving TFE3. The t(6;11) RCCs harbor a specific Alpha-TFEB gene fusion and were first officially recognized in the 2013 International Society of Urologic Pathology (ISUP) Vancouver classification of renal neoplasia. These two subtypes of translocation RCC have many similarities. Both were initially described in and disproportionately involve young patients, though adult translocation RCC may overall outnumber pediatric cases. Both often have unusual and distinctive morphologies; the Xp11 translocation RCCs frequently have clear cells with papillary architecture and abundant psammomatous bodies, while the t(6;11) RCCs frequently have a biphasic appearance with both large and small epithelioid cells and nodules of basement membrane material. However, the morphology of these two neoplasms can overlap, with one mimicking the other. Both of these RCCs underexpress epithelial immunohistochemical markers like cytokeratin and epithelial membrane antigen (EMA) relative to most other RCCs. Unlike other RCCs, both frequently express the cysteine protease cathepsin k and often express melanocytic markers like HMB45 and Melan A. Finally, TFE3 and TFEB have overlapping functional activity as these two transcription factors frequently heterodimerize and bind to the same targets. Therefore, on the basis of clinical, morphologic, immunohistochemical, and genetic similarities, the 2013 ISUP Vancouver classification of renal neoplasia grouped these two neoplasms together under the heading of "MiT family translocation RCC." This review summarizes our current knowledge of these recently described RCCs.

Uroplakins are markers of terminally differentiated urothelium. Uroplakin II (UPII) is a newly described sensitive marker for urothelial carcinoma (UC). The expression profile of UPII in different types of UC and its utility in the diagnostic setting are needed. We evaluated UPII expression in bladder tissue microarrays, including urothelial neoplasm of low malignant potential (n = 8), low-grade papillary UC (n = 72), noninvasive high-grade papillary UC (n = 77), UC in situ (n = 27), and invasive high-grade UC (INVUC) (n = 122). UPII expression in 52 breast carcinomas and 38 high-grade prostate adenocarcinomas was also assessed. UPII expression was compared with GATA binding protein 3 (GATA3) and estrogen receptor for its role in facilitating the differential diagnosis of the above 3 types of malignancy. UPII labeling was seen in 83.0% of UC overall, including 95.7% of noninvasive UC and 65.6% of INVUC. UPII labeling was not found in any breast and prostate carcinomas. In comparison, GATA3 labeling was seen in 91.6% of all UCs, including 96.4% of noninvasive UCs and 85.1% of INVUC, with stronger intensity and extent compared with UPII (P < .005). GATA3 labeled 2 (5%) of 38 high-grade prostate adenocarcinoma. Estrogen receptor nuclear labeling was seen in 13.0% of UCs and 12.5% of prostate carcinomas. UPII was highly specific (100%) but only moderately sensitive for UC and can therefore be a potentially useful marker to identify urothelial lineage and help distinguish UC from prostate cancer or, in conjunction with GATA3, from metastatic breast cancer.

During the last 30 years many advances have been made in kidney tumor pathology. In 1981, 9 entities were recognized in the WHO Classification. In the latest classification of 2004, 50 different types have been recognized. Additional tumor entities have been described since and a wide variety of prognostic parameters have been investigated with variable success; however, much attention has centered upon the importance of features relating to both stage and grade. The International Society of Urological Pathology (ISUP) recommends after consensus conferences the development of reporting guidelines, which have been adopted worldwide ISUP undertook to review all aspects of the pathology of adult renal malignancy through an international consensus conference to be held in 2012. As in the past, participation in this consensus conference was restricted to acknowledged experts in the field.

Summary Clear cell papillary renal cell carcinoma (CCPRCC) is a low-grade renal neoplasm with morphological characteristics mimicking both clear cell renal cell carcinoma (CCRCC) and papillary renal cell carcinoma (PRCC). However, despite some overlapping features, their morphological, immunohistochemical, and molecular profiles are distinct. Micro-RNAs (miRNAs) are small noncoding RNAs that play a crucial role in regulating gene expression and are involved in various biological processes, including cancer development. To better understand the biology of this tumor, we aimed to analyze the miRNA expression profile of a set of CCPRCC using microarray and quantitative reverse transcription–polymerase chain reaction. A total of 15 cases diagnosed as CCPRCC were used in this study. Among the most differentially expressed miRNA in CCPRCC, we found miR-210, miR-122, miR-34a, miR-21, miR-34b*, and miR-489 to be up-regulated, whereas miR-4284, miR-1202, miR-135a, miR-1973, and miR-204 were down-regulated compared with normal renal parenchyma. To identify consensus of differentially regulated miRNA between CCPRCC, CCRCC, and PRCC, we additionally determined differential miRNA expression using 2 publically available microarray data sets from the NCBI Gene Expression Omnibus database (GSE41282 and GSE3798). This comparison revealed that the miRNA expression profile of CCPRCC shows some overlapping characteristics between CCRCC and PRCC. Moreover, CCPRCC lacks dysregulation of important miRNAs typically associated with aggressive behavior. In summary, we describe the miRNA expression profile of a relatively infrequent type of renal cancer. Our results may help in understanding the molecular underpinning of this newly recognized entity.

Transcription factor GATA binding protein 3 (GATA3) has been suggested as a marker of urothelial carcinoma of the bladder and upper urinary tract. Its expression in primary and metastatic renal tumors has not been fully determined. We evaluated GATA3 expression in 47 oncocytomas, 196 primary renal cell carcinomas (RCCs) (71 clear cell, 53 papillary, 21 Xp11.2, 33 chromophobe RCCs, and 18 collecting duct carcinomas [CDC]), and 43 unrelated metastatic RCCs (41 clear cell and 2 Xp11.2 RCC). GATA3 nuclear expression was evaluated in tissue microarrays built from archival tissues using immunohistochemistry. Intensity (0 to 3+) and extent (percentage) of expression were assessed. Several cutoff values (>0%, >5%, and >10%) were evaluated to indicate GATA3 positivity. Among oncocytomas, 9 (19%) of 47 had some degree of nuclear GATA3 expression with median extent of 0% (0%-100%). When using either 5% or 10% cutoff values, 5 (11%) of 47 oncocytomas were positive. In primary RCCs, 6 (3%) of 196 had some degree of nuclear expression with a median extent of 0% (0%-100%). When using either 5% or 10% cutoff values, 2 cases remained positive (1%) (Xp11.2 and CDC). All metastatic RCCs were negative. We found an overall lack of GATA3 expression in primary and metastatic RCCs. GATA3 is expressed in a minority of oncocytomas, Xp11.2-RCC, and CDC. Given GATA3 positivity in upper urinary tract urothelial carcinoma, our findings support a role for GATA3 in the differential diagnosis of primary renal masses and a utility in the interrogation of metastatic tumors of unknown primary in the presence of a renal mass.

Summary Differential diagnosis of collecting duct carcinoma (CDC) from invasive upper tract urothelial carcinoma (UTUC) can be challenging. PAX8 and p63 are 2 markers often used in this setting. GATA binding protein 3 (GATA3) is a marker of urothelial differentiation. We investigated GATA3 expression in CDC and UTUC and its use in this differential. Eighteen CDC and 25 UTUC cases were used to build 2 tissue microarrays. GATA3, p63, and PAX8 nuclear expression was evaluated using standard immunohistochemistry. Staining intensity and percentage of positive cells were assessed. Sensitivity, specificity, and positive and negative predictive values of the markers and their combination were also evaluated. We found GATA3 positivity in 22 (88%) of 25 UTUCs and 1 (6%) of 18 CDCs. The median GATA3 extent of expression was higher in UTUC than in CDC (74% versus 0%, P = .00). We found p63 positivity in 23 (92%) of 25 UTUCs and 2 (11%) of 18 CDCs. PAX8 was positive in 3 (12%) of 25 UTUCs and all (100%) CDCs. GATA3 sensitivity and specificity for UTUC were 88% and 94%, respectively. p63 sensitivity and specificity for UTUC were 92% and 89%, respectively. The p63+/PAX8− profile showed higher sensitivity for UTUC than did the GATA3+/PAX8− profile (80% versus 76%). Both showed a specificity of 100% for UTUC. GATA3+ or p63+/PAX8− sensitivity and specificity for UTUC were 84% and 100%, respectively. Immunohistochemical expression of GATA3 was higher in UTUC, suggesting a potential role for distinguishing UTUC from CDC. Adding this marker to the combination panel of p63 and PAX8 might improve its performance in the diagnosis of epithelial neoplasms involving the renal sinus.

Background The aim of this study was to evaluate the outcome of patients with translocation renal cell carcinoma (RCC) treated with partial nephrectomy. Patients and Methods Our institutional review board-approved renal mass registry was queried for patients who underwent partial nephrectomy for a pathologically confirmed translocation RCC. We describe the demographic, clinical, pathological, and follow-up data for this series of patients. Results Between 2003 and 2013, 1897 patients with RCC were treated at our institution with a radical or partial nephrectomy. In total, 10 (0.5%) patients were diagnosed with a translocation RCC. Of these patients, 4 (40%) underwent treatment with partial nephrectomy for an incidentally detected small renal mass (mean imaging diameter, 2.6 cm [range, 1.0-4.2 cm]). During a mean follow-up of 37 months (range, 8-81 months), all patients were alive without evidence of disease. Conclusion At short-term follow-up, partial nephrectomy appears to be an effective treatment option for patients with small translocation RCCs. Larger studies are required to more extensively investigate the optimal treatment of these potentially aggressive tumors.

The transcription factor Sox10 mediates the differentiation of neural crest–derived cells, and Sox10 labeling by immunohistochemistry (IHC) is used clinically primarily to support the diagnosis of melanoma. Sox10 expression by IHC has been previously documented in benign breast myoepithelial cells but not in breast carcinomas. Here, we report the first systematic study of Sox10 expression in invasive ductal carcinomas subclassified by IHC-defined molecular subtype (100 cases), as well as in 24 cases of ductal carcinoma in situ and 44 mammary fibroepithelial neoplasms. Tissue microarrays containing 168 primary breast tumors were subjected to IHC for Sox10. The extent of nuclear Sox10 labeling was scored by percentage labeling as follows: 0 (0%), 1+ (1%–25%), 2+ (25%–50%), 3+ (50%–75%), and 4+ (>75%). Overall, 40 (40%) of 100 invasive breast carcinomas demonstrated Sox10 immunoreactivity, which was seen primarily in the basal-like, unclassified triple-negative, and metaplastic carcinomas. Sox10 labeling was seen in 66% (38/58) of the basal-like, unclassified triple-negative, and metaplastic carcinomas as compared with 5% (2/42) of the luminal A, luminal B, and Her-2 carcinomas (P < .00001). Sox10 labeling was seen in 1 (4%) of 24 cases of ductal carcinoma in situ, which was negative for estrogen receptor/progesterone receptor. No labeling was seen in the stromal component of phyllodes tumors or fibroadenomas. These findings show that breast carcinoma must be considered in the differential diagnosis of melanoma for an S100-positive, Sox10-positive metastatic malignant neoplasm. Sox10 expression in the basal-like, unclassified triple-negative, and metaplastic carcinomas types supports the concept that these neoplasms show myoepithelial differentiation.

Hepatocellular carcinoma and intrahepatic cholangiocarcinoma account for 95% of primary liver cancer. For each of these malignancies, the outcome is dismal; incidence is rapidly increasing, and mechanistic understanding is limited. We observed abnormal proliferation of both biliary epithelium and hepatocytes in mice after genetic manipulation of Yes-associated protein, a transcription coactivator. Here, we comprehensively documented Yes-associated protein expression in the human liver and primary liver cancers. We showed that nuclear Yes-associated protein expression is significantly increased in human intrahepatic cholangiocarcinoma and hepatocellular carcinoma. We found that increased Yes-associated protein levels in hepatocellular carcinoma are due to multiple mechanisms including gene amplification and transcriptional and posttranscriptional regulation. Survivin, a member of the inhibitors-of-apoptosis protein family, has been reported as an independent prognostic factor for poor survival in both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. We found that nuclear Yes-associated protein expression correlates significantly with nuclear Survivin expression for both intrahepatic cholangiocarcinoma and hepatocellular carcinoma. Furthermore, using mice engineered to conditionally overexpress Yes-associated protein in the liver, we found that Survivin messenger RNA expression depends upon Yes-associated protein levels. Our findings suggested that Yes-associated protein contributes to primary liver tumorigenesis and likely mediates its oncogenic effects through modulating Survivin expression.

In breast cancer, amplification of MYC is consistently observed in aggressive forms of disease and correlates with poor prognosis and distant metastases. However, to date, a systematic analysis of MYC amplification in metastatic breast cancers has not been reported. Specifically, whether the MYC amplification status may change in metastases in comparison to the corresponding primary breast tumor, and potential variability among different metastases within the same patient have also not been assessed. We generated single patient tissue microarrays consisting of both primary breast carcinomas and multiple matched systemic metastases from 15 patients through our previously described rapid autopsy program. In total, the 15 tissue microarrays contained 145 primary tumor spots and 778 spots derived from 180 different metastases. In addition, two separate tissue microarrays were constructed composed of 10 matched primary breast cancers and corresponding solitary metastases sampled not at autopsy but rather in routine surgical resections. These two tissue microarrays totaled 50 primary tumor spots and 86 metastatic tumor spots. For each case, hormone receptor status, HER2/neu, EGFR and CK5/6 expression were assessed, and the cases were characterized as luminal, basal-like or HER2 based on published criteria. Both fluorescence in situ hybridization and immunohistochemistry for MYC was performed on all cases. Of the 25 cases, 24 were evaluable. While 4 of 24 primary tumors (16%) demonstrated MYC amplification, an additional 6 (25% of total evaluable cases) acquired MYC amplification in their systemic metastases. Of note, there was remarkably little heterogeneity in MYC copy number among different metastases from the same patient. MYC immunoreactivity was increased in metastases relative to matched primaries in the surgical cohort, although there was no perfect correlation with MYC amplification. In conclusion, amplification of MYC is a frequent event in breast cancer, but occurs more frequently as a diffuse, acquired event in metastatic disease than in the corresponding primary. These observations underscore the importance of MYC in breast cancer progression/metastasis, as well as its relevance as a potential therapeutic target in otherwise incurable metastatic disease.

A case with a renal mass diagnosed as metanephric stromal tumor is presented. A 6-year-old boy presented with frequently recurring urinary tract infections. He had been followed up at different medical centers for the last 2 years with a 2 × 2 cm simple cyst localized in the inferior pole of the left kidney. At our center, ultrasonography revealed a heterogeneous mass in the left kidney with a central cystic component. The patient underwent operation for left renal mass, and heminephrectomy was performed. The 5 × 4 × 2.5 cm left heminephrectomy specimen showed a partially cystic mass composed of bland spindle cells distributed haphazardly, entrapping tubules and glomeruli and producing fine collarettes around some tubules. The cysts were lined with a 1-layered flat or cuboidal epithelium. Histopathologically, the tumor was diagnosed as metanephric stromal tumor. Metanephric stromal tumor is a rare renal neoplasm of childhood that can present as a cystic mass, and the solid component can go radiologically undetected because of the blurring infiltrative margins. By presenting this rare entity, the authors suggest that this should be included in the differential diagnosis, thereby helping to avoid complications and unnecessary treatment.

Approximately 10% to 15% of human cancers lack detectable telomerase activity, and a subset of these maintain telomere lengths by the telomerase-independent telomere maintenance mechanism termed alternative lengthening of telomeres (ALT). The ALT phenotype, relatively common in subtypes of sarcomas and astrocytomas, has rarely been reported in epithelial malignancies. However, the prevalence of ALT has not been thoroughly assessed across all cancer types. We therefore comprehensively surveyed the ALT phenotype in a broad range of human cancers. In total, two independent sets comprising 6110 primary tumors from 94 different cancer subtypes, 541 benign neoplasms, and 264 normal tissue samples were assessed by combined telomere-specific fluorescence in situ hybridization and immunofluorescence labeling for PML protein. Overall, ALT was observed in 3.73% (228/6110) of all tumor specimens, but was not observed in benign neoplasms or normal tissues. This is the first report of ALT in carcinomas arising from the bladder, cervix, endometrium, esophagus, gallbladder, kidney, liver, and lung. Additionally, this is the first report of ALT in medulloblastomas, oligodendrogliomas, meningiomas, schwannomas, and pediatric glioblastoma multiformes. Previous studies have shown associations between ALT status and prognosis in some tumor types; thus, further studies are warranted to assess the potential prognostic significance and unique biology of ALT-positive tumors. These findings may have therapeutic consequences, because ALT-positive cancers are predicted to be resistant to anti-telomerase therapies.

Rationale and Objectives The aim of this prospective study was to investigate using multiparametric and multinuclear magnetic resonance imaging during preoperative systemic therapy for locally advanced breast cancer. Materials and Methods Women with operable stage 2 or 3 breast cancer who received preoperative systemic therapy were studied using dynamic contrast-enhanced magnetic resonance imaging, magnetic resonance spectroscopy, and 23 Na magnetic resonance. Quantitative metrics of choline peak signal-to-noise ratio, total tissue sodium concentration, tumor volumes, and Response Evaluation Criteria in Solid Tumors were determined and compared to final pathologic results using receiver-operating characteristic analysis. Hormonal markers were investigated. Statistical significance was set at P Results Eighteen eligible women were studied. Fifteen responded to therapy, four (22%) with pathologic complete response and 11 (61%) with pathologic partial response. Three patients (17%) had no response. Among estrogen receptor–positive, HER2-positive, and triple-negative phenotypes, observed frequencies of pathologic complete response, pathologic partial response, and no response were 2, 5, and 0; 1, 4, and 0; and 1, 1, and 3, respectively. Responders (pathologic complete response and pathologic partial response) had the largest reductions in choline signal-to-noise ratio (35%, from 7.2 ± 2.3 to 4.6 ± 2; P P = .13) after the first cycle. Total tissue sodium concentration significantly decreased in responders (27%, from 66 ± 18 to 48.4 ± 8 mmol/L; P = .01), while there was little change in nonresponders (51.7 ± 7.6 to 56.5 ± 1.6 mmol/L; P = .50). Lesion volume decreased in responders (40%, from 78 ± 78 to 46 ± 51 mm 3 ; P = .01) and nonresponders (21%, from 100 ± 104 to 79.2 ± 87 mm 3 ; P = .23) after the first cycle. The largest reduction in Response Evaluation Criteria in Solid Tumors occurred after the first treatment in responders (18%, from 24.5 ± 20 to 20.2 ± 18 mm; P = .01), with a slight decrease in tumor diameter noted in nonresponders (17%, from 23 ± 19 to 19.2 ± 19.1 mm; P = .80). Conclusions Multiparametric and multinuclear imaging parameters were significantly reduced after the first cycle of preoperative systemic therapy in responders, specifically, choline signal-to-noise ratio and sodium. These new surrogate radiologic biomarkers maybe able to predict and provide a platform for potential adaptive therapy in patients.

The Ewing sarcoma (ES) family of tumors is characterized by nonrandom chromosomal translocations involving the EWSR1 gene on chromosome 22 with one of the members of the ETS family of transcription factors. The majority of ES tumors are characterized by a balanced translocation t(11;22)(q24;q12), which results in the fusion of the 5' portion of EWSR1 gene with the 3'end of the FLI1 gene. Fusions with ERG, another member of the ETS family, occur in less than 10% of ES tumors, and can arise through complex chromosomal rearrangements. Here, we report a case of a 5-year-old female with an ES tumor in the thoracic region. G-banding and spectral karyotyping analysis demonstrated 46,XX,t(1;21;7)(q25;q22.3;q22). Metaphase fluorescence in situ hybridization (FISH) using the EWSR1 break-apart probe demonstrated a normal signal on both apparently normal chromosomes 22, and an additional EWSR1-5' signal on the derivative chromosome 21. Reverse-transcriptase polymerase chain reaction analysis of RNA isolated from the tumor demonstrated a EWSR1-ERG fusion transcript, fusing exon 7 of EWSR1 and exon 11 of ERG. These results are consistent with an additional copy of the 5' portion of EWSR1, which inverted and then inserted on chromosome 21 and fused to the 3' end of ERG. To our knowledge, this is the first report of a EWSR1-ERG fusion in an ES tumor with an apparently duplicated 5' portion of EWSR1, and with a complex translocation involving chromosomes 1, 7, and 21. This case adds to the spectrum of genetic rearrangements identified in ES tumors.

Bcl-2 is an antiapoptotic protein that promotes cell survival, but also may block proliferation. In breast cancer, bcl-2 expression correlates with favorable prognosis and estrogen receptor (ER) positivity. However, experimental data have paradoxically suggested that bcl-2 promotes chemoresistance and metastasis. A direct and comprehensive comparison of bcl-2 expression between primary breast carcinomas and paired distant metastases has not been performed. We completed rapid autopsies on 17 patients with archived primary tumors and metastatic breast carcinoma, and created single-patient tissue microarrays containing each patient’s primary tumor and matched metastases. Expression of bcl-2, ER, progesterone receptor, and HER-2 in primary tumors and matched metastases were compared by immunohistochemistry. All 11 ER-positive cases showed bcl-2 labeling in the primary tumor, whereas only 3 of 6 ER-negative cases did (P = 0.029). In 10 cases, bcl-2 labeling in metastases was similar to that of the primary, although 3 cases showed significant variation among metastases. In six other cases, bcl-2 labeling was lost or significantly diminished in metastases. Five of the latter cases were Luminal A (ER-positive, HER-2-negative) primaries, three of which lost hormone receptors in metastases. Only 1 of 17 cases showed an increase in bcl-2 labeling in metastases compared with the paired primary tumor. In conclusion, bcl-2 is infrequently upregulated in metastatic breast carcinoma. Instead, downregulation of bcl-2 expression may occur in the setting of hormone therapy resistance. Our findings call into question the potential utility of anti-bcl-2 therapy in metastatic breast cancer.

We report a case of a patient with invasive breast carcinoma which demonstrated HER-2 gene amplification on core biopsy, who relapsed while on adjuvant Trastuzumab therapy following her mastectomy and ultimately died 15 months after diagnosis. Surprisingly, analysis of multiple metastases harvested at rapid autopsy demonstrated no evidence of HER-2 gene amplification. Retrospective examination of the carcinoma in the patient’s mastectomy specimen revealed only focal HER-2 amplification within the tumor, localized to the region of the prior core biopsy site. This case highlights several important issues in HER-2 testing of breast cancer, including core biopsy-excision specimen discordance, primary-metastasis discordance, and potential selection for unamplified portions of a heterogeneously-amplified tumors by Trastuzumab.

Development of facile, sensitive, specific, and economical assays for the analysis of methylated alleles is crucial to the use of methylated biomarkers for cancer detection. We hereby report a novel method, MethySYBR, a SYBR green-based PCR assay for the dual analysis of DNA methylation and CpG methylation density. MethySYBR begins with multiplex PCR to enable the simultaneous amplification of many discrete target alleles in a single reaction using as little as 3 pg of bisulfite-converted DNA. In the second round of PCR, the specific methylated target is quantified from multiplex products using both nested methylation-independent and methylation-specific primer sets. Moreover, the use of SYBR green dye during quantitative PCR enables melting curve analysis of target amplicons to determine the methylation density of CpG sites on target alleles. To establish proof of principle, two cancer-specific methylated genes, RASSF1A and OGDHL, were assessed by MethySYBR. We demonstrated that MethySYBR sensitively detected methylated alleles in the presence of a 100,000-fold excess of unmethylated allele. Furthermore, MethySYBR was shown to be capable of analyzing minute amounts of DNA from paraffin-embedded tissue. Therefore, the MethySYBR assay is a simple, highly specific, highly sensitive, high-throughput, and cost-effective method that is widely applicable to basic and clinical studies of DNA methylation.

Renal cell carcinoma (RCC) comprises about 5% of pediatric renal neoplasms. It has been recognized as a second malignancy in multiple reports. It is generally symptomatic at diagnosis, and most children with RCC present with more locally advanced disease than do adults. Contemporary investigation of pediatric RCC has demonstrated that a large percentage of these tumors bear cytogenetic translocations involving the MiT family of transcription factors. Surgical therapy for these children resembles operative intervention for adult RCC, though debate continues about the precise role of lymph node dissection. There are no adequately powered studies to support conclusions about adjuvant or neoadjuvant chemotherapy for children with RCC. This may be ameliorated by a multi-institutional protocol which is enrolling patients.

A checklist based approach to reporting the relevant pathologic details of renal cell carcinoma resection specimens improves the completeness of the report. Karyotypic evaluation of renal neoplasms has refined but also complicated their classification. The number of diagnostic possibilities has increased and the importance of distinguishing different tumor types has been underscored by dramatic variation in prognosis and the development of targeted therapies for specific subtypes. The increasing number of recognized renal neoplasms has implications for handling renal resection specimens. Furthermore, the prognostic significance of other features of renal neoplasms related to grade and stage has been demonstrated. This guideline for the handling of renal resection specimens will focus on problem areas in the evolving practice of diagnosis, grading, and staging of renal neoplasms. The accompanying checklist will serve to ensure that all necessary details of the renal resection specimen are included in the surgical pathology report.

Renal cell carcinomas in young patients constitute a morphologically and genetically heterogeneous group. Twenty percent belong to the newly recognized Xp11.2 translocation-associated family and rare tumors arise from nephroblastoma. Aberrant Wnt signaling through beta-catenin mutation has been implicated in nephroblastoma pathogenesis and has been found to synergize with WT1 mutations. To characterize Wnt signaling activity in renal cell carcinomas in young patients, we gathered 34 tumors (three clear cell, ten Xp11.2 translocation associated, five papillary, two chromophobe, two collecting duct, one neuroblastoma associated, eight unclassified renal cell carcinomas, and three carcinomas combined with nephroblastoma) from patients less than 22 years. Expression of beta-catenin, its homologue gamma-catenin, and of WT1 was assessed by immunohistochemistry in 30 tumors, and sequence analysis of CTNNB1, CTNNG1, and WT1 genes was performed in 25 tumors. Cytoplasmic beta-catenin accumulation was demonstrated in two papillary carcinomas, one neuroblastoma-associated carcinoma, and two carcinomas arising from nephroblastoma. The pattern of gamma-catenin expression paralleled that of beta-catenin but its signal intensity was lower in 22, equal in 7, and stronger only in 1 tumor, respectively. Four tumors showed nuclear WT1 expression. One Xp11.2 translocation-associated carcinoma presented a rare intronic CTNNB1 single nucleotide polymorphism and cytoplasmic beta-catenin accumulation. There were no further CTNNB1 or CTNNG1 sequence alterations. A WT1 mutation was found in the nephroblastoma component of a carcinoma arising from nephroblastoma. These findings suggest Wnt signaling pathway activation only in a minority of renal cell carcinomas in young patients. CTNNB1 mutations are rare events. Cytoplasmic beta-catenin accumulation in an Xp11.2-associated carcinoma suggests potential interaction of Wnt signaling components with microphthalmia transcription factor family also in Xp11.2 translocation carcinomas. WT1 mutation in the nephroblastoma component of a mixed-type renal cell carcinoma provides direct evidence for clonal independence of nephroblastoma and carcinoma components in this exceptional tumor.

We have examined the mechanism of normal DNA methyltransferase 1 (DNMT1) degradation as well as its mechanism of dysregulation in cancer. We have previously reported that DNMT1 protein levels were elevated and abnormally stabilized because of defective degradation through its N-terminal destruction domain. Here, we report that DNMT1 was abnormally stabilized in several cancer cell lines and that, in cells with normal DNMT1 destruction, depletion of CDC20 or FZR1 (two substrate recognition adaptor components of the anaphase-promoting complex) resulted in stabilization of DNMT1 that was partially dependent on the N-terminal destruction domain, thus implicating this cell cycle regulator in the destruction of DNMT1. MAD2, an inhibitor of CDC20, was shown to stabilize DNMT1 levels, and overexpression of MAD2, a consequence of retinoblastoma (RB) pathway dysregulation, was shown to correlate with impaired G1 phase DNMT1 destruction and RB inactivation by hyperphosphorylation in several normal and cancer cell lines. Furthermore, in a series of 85 cases of human breast cancer, a moderately strong, but highly significant, correlation between MAD2 and DNMT1 immunohistochemical staining was observed, yielding a Spearman rank order correlation coefficient of 0.37 (P < 0.001). This suggests that RB pathway inactivation, a common dysfunction in cancer cells, may be the underlying cause of DNMT1 dysregulation.

Purpose The purpose of this study was to evaluate whether initial diagnostic technique influenced the ability to identify anaplastic histology, to determine the time interval to diagnosis of anaplasia, and to delineate the incidence of discordant pathology in bilateral Wilms' tumor. We hypothesized that delay in diagnosis of anaplasia could affect time to appropriate surgery and intensive multimodality therapy. Methods One hundred eight-nine children were enrolled in the fourth National Wilms' Tumor Study with synchronous bilateral tumors, 27 of whom were eventually shown to have anaplastic histology. Initial diagnostic technique, time interval to diagnosis of anaplasia, and the incidence of discordant pathology were determined. Results Anaplasia was identified in 0 of 7 tumors by core needle biopsy, 3 of 9 tumors by open wedge biopsy, and in 7 of 9 cases by partial or complete nephrectomy. The mean duration of first chemotherapy regimen (DD or EE) was 20, 39, and 36 weeks, respectively, before anaplasia was identified at second surgery. Discordant pathology between bilateral tumors was identified on final tissue diagnosis in 20 patients. Only 4 patients had anaplastic tumors in both kidneys. Conclusions Core needle biopsy did not identify anaplasia in 7 of 7 children. Open biopsy or partial/complete nephrectomy identified anaplasia at initial diagnostic procedure in 10 of 18 children. Twenty of 24 patients at final tissue diagnosis had discordant pathology between the 2 kidneys. Earlier interval incisional biopsy or resection may identify anaplastic histology and limit the duration of chemotherapy targeted to favorable histology for children with bilateral Wilms' tumor and anaplasia.

Metanephric neoplasms represent a spectrum of differentiated lesions that seem most likely to be related to Wilms tumor. These neoplasms include a pure stromal lesion, a pure epithelial lesion (MA), and a mixed epithelial-stromal lesion (MAF). The continuity of these lesions with Wilms tumor has been demonstrated best in the epithelial lesions. The relationship of Wilms tumor, MAF with mitoses or combined MA/Wilms tumor lesions, and usual MAF or usual MA may be viewed as analogous to that of neuroblastoma, differentiating neuroblastoma, and ganglioneuroma, in which progressively more mature or differentiated counterparts of malignant embryonal lesions are associated with a greater probability of benign clinical behavior. Such a spectrum already is recognized for cystic ILNR-derived nephroblastic lesions, ranging from cystic Wilms tumor, cystic partially differentiated nephroblastoma, and cystic nephroma. Although this concept implies that the more active lesions (Wilms tumor) mature with time into inactive ones (usual MAFs or MA), the converse (that an active Wilms tumor can arise within an inactive usual MAF or MA) remains possible.

A subset of renal carcinomas that most commonly affect young patients has been characterized by various translocations that involve chromosome Xp11.2; all result in gene fusions that involve the TFE3 transcription factor gene. In the past few years, several different Xp11.2-translocation carcinomas have been identified and characterized at the morphologic and molecular levels. These include a distinctive renal carcinoma that bears a translocation with the identical breakpoints and identical resulting ASPL–TFE3 gene fusion as alveolar soft part sarcoma (ASPS), a rare pediatric soft tissue neoplasm of uncertain histogenesis. These Xp11.2 translocation carcinomas are now accepted as a distinctive entity in the 2004 World Health Organization’s renal tumor classification [1]. In addition, a novel and unusual epithelioid renal neoplasm that is characterized by a recurrent t(6:11)(p11.2;q12) chromosome translocation has been described, and recently was found to bear a fusion that involves the related TFEB transcription factor gene. Because TFEB and TFE3 are members of the MiTF/TFE family of transcription factors, and the Xp11 and t(6;11) translocation neoplasms share clinical morphologic, immunohistochemical, and molecular features, we propose to expand the existing category of Xp11-translocation carcinomas and group these neoplasms under a new category of ‘‘MiTF/TFE family translocation carcinomas.’’ This article describes the morphologic and molecular features of these recently-defined neoplastic entities.

We report that DNA methyltransferase 1 (DNMT1) expression is dysregulated in breast cancer. The elevated protein levels are not a result of increased mRNA levels, but rather an increase in protein half-life. We found that DNMT1 protein levels were elevated in breast cancer tissues and in MCF-7 breast cancer cells relative to normal human mammary epithelial cells (HMECs) without a concomitant increase in DNMT1 mRNA or proliferative fraction. Although DNMT1 mRNA levels were properly S-phase-regulated in both cell types, DNMT1 protein levels did not follow S-phase fraction in MCF-7 cells. Rather, an increase in DNMT1 protein stability was found for MCF-7 cells relative to HMECs, and a destruction domain was mapped to the N-terminal 120 amino acids of DNMT1, which was required for its proper ubiquitination and degradation in HMECs. Furthermore, overexpression of DNMT1 with this deleted destruction domain in HMECs resulted in significantly increased genomic 5-methylcytosine levels relative to overexpression of the full-length protein. The regulation of DNMT1 destruction via this domain may be dysfunctional in cancer cells leading to subsequent cytosine hypermethylation in the genome.

While often underappreciated, the gallbladder may be affected by a variety of pathological processes that have specific clinical correlates. Reactive epithelial changes within typical cholecystitis may mimic dysplasia. Usual stone-associated cholecystitis has only mild inflammation, but variants of cholecystitis may have abundant xanthoma cells, eosinophils, or lymphocytes and plasma cells. Metaplasia from the normal columnar absorptive epithelium into mucinous epithelium occurs in a subset of cases, and a further subset may progress to dysplasia, which is thought to be the main precursor of invasive gallbladder carcinoma. Unlike the situation in the colon, adenomas in the gallbladder are rare and not likely to be the precursors of most carcinomas. Most invasive carcinomas of the gallbladder present at advanced stage, and therefore are highly lethal. While their morphology may be identical to that of other pancreatobiliary carcinomas, molecular data are emerging to suggest that these neoplasms are genetically distinct. Several more uncommon types of gallbladder carcinoma, such as papillary adenocarcinomas and small cell carcinoma, have different clinical implications, so it is important that they are recognized. p16 and p53 inactivation are consistent findings in gallbladder carcinomas, but novel abnormalities are revealed by recent global genetic analysis of these neoplasms.

Using global gene expression analyses, multiple novel tumor markers overexpressed in infiltrating ductal adenocarcinomas of the pancreas have recently been identified. However, the expression of these markers in morphologically similar adenocarcinomas of the biliary tree has not been investigated. The purpose of the present study was 3-fold. First, we used 8 markers that have been shown to be overexpressed in whole tissue sections of pancreatic adenocarcinomas to validate tissue microarrays (TMAs) created from a series of pancreatic adenocarcinomas (n=68). The labeling patterns of 6 epithelial markers (fascin, mucin 4, 14-3-3sigma, prostate stem cell antigen, topoisomerase IIalpha, and cdc2/p34) were concordant with previously published studies on whole tissue sections, yet required far fewer slides and reagents. Mesothelin, an epithelial marker, and heat shock protein 47, a marker of peritumoral desmoplasia, showed lower levels of expression in the TMAs when compared with whole tissue sections. Second, we examined the previously unknown expression of the same 8 novel tumor proteins in cancers of the biliary tree by using TMAs created from a series of intrahepatic cholangiocarcinomas, gallbladder adenocarcinomas, and adenocarcinomas of the distal common bile duct (n=38). Each of the 8 markers was overexpressed in the biliary cancers, ranging from 14% demonstrating at least focal labeling with prostate stem cell antigen to 100% labeling with cdc2/p34. Most of the markers showed lower frequencies of expression in the biliary tract carcinomas in comparison to the pancreatic adenocarcinomas. In addition, expression patterns varied with location in the biliary system (intrahepatic versus gallbladder versus distal common bile duct). These differences were statistically significant (P

Notch signaling regulates cell fate decisions in a wide variety of adult and embryonic tissues. Here we show that Notch pathway components and Notch target genes are upregulated in invasive pancreatic cancer, as well as in pancreatic cancer precursors from both mouse and human. In mouse pancreas, ectopic Notch activation results in accumulation of nestin-positive precursor cells and expansion of metaplastic ductal epithelium, previously identified as a precursor lesion for pancreatic cancer. Notch is also activated as a direct consequence of EGF receptor activation in exocrine pancreas and is required for TGF alpha-induced changes in epithelial differentiation. These findings suggest that Notch mediates the tumor-initiating effects of TG alpha by expanding a population of undifferentiated precursor cells.

The K-ras oncogene is activated in approximately 90% of pancreatic adenocarcinomas, and the DPC4 (MADH4/SMAD4) tumor suppressor gene is inactivated in approximately 55% of pancreatic adenocarcinomas. The contributions of these genetic alterations to the development of adenocarcinoma of the ampulla of Vater have not been fully established. One hundred forty surgically resected ampullary adenocarcinomas (76 with associated adenomas with high-grade dysplasia) were immunohistochemically labeled for the DPC4 gene product, and in 85 cases the results were correlated with the status of the K-ras oncogene from previously reported data. The results were correlated with clinical outcome and with other pathologic predictors of prognosis. Complete loss of Dpc4 labeling was identified in 34% (95% confidence interval [CI]: 26%, 43%) of the invasive carcinomas and in none (upper 95% CI: 6%) of the associated adenomas. Focal loss of Dpc4 was seen in three (4%; 95% CI: 1%, 14%) of the areas of high-grade dysplasia. Complete loss of Dpc4 expression was seen in 28/77 intestinal-type tumors, in 17/46 pancreaticobiliary-type tumors, and in 0/10 colloid carcinomas. Activating point mutations in the K-ras gene were identified in 40% of the invasive cancers. There was no correlation between K-ras gene mutations and Dpc4 expression and no correlation between these variables and survival. The overall 5-year survival rate was 38%. Lymph node metastases were associated with shorter survival (P =.03). Loss of Dpc4 expression occurs in approximately one third of invasive ampullary cancers but is not seen in adenomas; thus, loss of Dpc4 expression occurs late in ampullary carcinogenesis. Although ampullary and pancreatic adenocarcinomas share histologic and molecular features, ampullary carcinomas are less likely to show loss of Dpc4 expression or K-ras gene mutations.

The unbalanced translocation, der(17)t(X;17)(p11.2;q25), is characteristic of alveolar soft part sarcoma (ASPS). We have recently shown that this translocation fuses the TFE3 transcription factor gene at Xp11.2 to ASPL, a novel gene at 17q25. We describe herein eight morphologically distinctive renal tumors occurring in young people that bear the identical ASPL-TFE3 fusion transcript as ASPS, with the distinction that the t(X;17) translocation is cytogenetically balanced in these renal tumors. A relationship between these renal tumors and ASPS was initially suggested by the cytogenetic finding of a balanced t(X;17)(p11.2;q25) in two of the cases, and the ASPL-TFE3 fusion transcripts were then confirmed by reverse transcriptase-polymerase chain reaction. The morphology of these eight ASPL-TFE3 fusion-positive renal tumors, although overlapping in some aspects that of classic ASPS, more closely resembles renal cell carcinoma (RCC), which was the a priori diagnosis in all cases. These tumors demonstrate nested and pseudopapillary patterns of growth, psammomatous calcifications, and epithelioid cells with abundant clear cytoplasm and well-defined cell borders. By immunohistochemistry, four tumors were negative for all epithelial markers tested, whereas four were focally positive for cytokeratin and two were reactive for epithelial membrane antigen (EMA) (one diffusely, one focally). Electron microscopy of six tumors demonstrated a combination of ASPS-like features (dense granules in four cases, rhomboid crystals in two cases) and epithelial features (cell junctions in six cases, microvilli and true glandular lumens in three cases). Overall, although seven of eight tumors demonstrated at least focal epithelial features by electron microscopy or immunohistochemistry, the degree and extent of epithelial differentiation was notably less than expected for typical RCC. We confirmed the balanced nature of the t(X;17) translocation by fluorescence in situ hybridization in all seven renal tumors thus analyzed, which contrasts sharply with the unbalanced nature of the translocation in ASPS. In summary, a subset of tumors previously considered to be RCC in young people are in fact genetically related to ASPS, although their distinctive morphological and genetic features justify their classification as a distinctive neoplastic entity. Finally, the finding of distinctive tumors being associated with balanced and unbalanced forms of the same translocation is to our knowledge, unprecedented.

We report two cases of a hitherto undescribed pediatric renal neoplasm that is distinctive at the morphological, immunohistochemical, ultrastructural, and cytogenetic levels. On light microscopy, the tumors are composed of nests of polygonal, clear to eosinophilic cells associated with a subpopulation of smaller cells that surround hyaline material. Despite their epithelioid morphology, these tumors do not label immunohistochemically for epithelial markers but instead label focally for melanocytic markers HMB45 and Melan A. The hyaline material is positive with periodic acid-Schiff and methenamine-silver histochemical stains, and labels immunohistochemically for type 4 collagen. Ultrastructural examination confirms that it represents basement membrane material. Cytogenetic analysis reveals the identical t(6;11)(p21.1;q12) chromosome translocation as the sole abnormality in these two tumors, confirming their identity and distinctive nature.

We report 4 distinctive renal epithelial neoplasms that are essentially identical at the morphologic and immunohistochemical levels and do not fit an accepted category in the existing classification of these lesions. The patients were all females, with ages ranging from 32 to 79 years (mean, 50 years). The tumors were well circumscribed and were composed of uniform, predominantly low cuboidal cells with eosinophilic, focally vacuolated cytoplasm. Tumor cells generally formed interconnecting tubules, with smaller areas of cordlike growth and spindling in a bubbly, myxoid stroma. All tumors were confined to the kidney, and all were immunoreactive for high-molecular-weight cytokeratin 34betaE12, cytokeratin 7, epithelial membrane antigen, and cytokeratin cocktail AE1/3. Only 1 tumor was focally immunoreactive for Ulex europaeus agglutinin. Ultrastructural study showed tumor cells forming tubular structures reminiscent of the loop of Henle or distal convoluted tubule. Follow-up in all 4 cases was benign. These distinctive tumors may be confused with aggressive sarcomatoid renal cell carcinomas because of their spindled morphology. The morphologic, immunohistochemical, and ultrastructural features of these lesions indicate differentiation toward distal nephron segments. Similar tumors probably have been reported among low-grade collecting duct carcinomas or tumors "possibly related to the loop of Henle."

The tumor-suppressor protein Dpc4 (Smad4, Madh4) regulates gene expression. On binding of an extracellular ligand of the extensive transforming growth factor (TGF) superfamily to its cognate receptor complex, latent cytoplasmic Dpc4 is activated and translocated into the nucleus to function as part of various DNA-binding transcriptional activator complexes. The most relevant ligand/receptor pair to control the tumor suppressive function of Dpc4 remains uncertain, but is usually assumed to be TGF-beta and its heteromeric receptor. We exploited a fortuitous experiment of nature to directly test this hypothesis: the TGF-beta type II receptor gene is inactivated by mutation in nearly all colorectal carcinomas having microsatellite instability, as seen in hereditary nonpolyposis colorectal cancer (HNPCC) and in sporadic medullary colorectal cancers. Using a specific and sensitive immunohistochemical label for Dpc4, we examined nuclear localization of Dpc4 in 13 HNPCC, six medullary, and 41 sporadic nonmedullary colorectal carcinomas. In agreement with published rates, two (5%) of 41 sporadic tumors showed complete loss of Dpc4 protein, indicative of genetic inactivation. All 13 HNPCC and six medullary tumors had intact cytoplasmic and nuclear Dpc4 localization. The TGFBR2 gene was sequenced in three of the cancers from patients with HNPCC, and all of these harbored inactivating mutations. The specificity of the immunohistochemical assay was demonstrated in xenograft tumors of syngeneic cell lines that differed in DPC4 genetic status because of an engineered gene knockout. Thus, nuclear localization of Dpc4 can be maintained in cells with inactivated TGF-beta type II receptors, suggesting the persistence of tumor-suppressive action of an upstream signaling input, most likely a ligand/receptor complex distinct from TGF-beta. Identification of the relevant input would be expected to have implications for the understanding of tumorigenesis and the design of rational biological therapy.

DPC4 (MADH4, SMAD4) encodes a nuclear transcription factor shown to be genetically inactivated in over one-half of conventional infiltrating ductal adenocarcinomas of the pancreas. Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas have been suggested to be distinct neoplasms with a significantly less aggressive course than conventional ductal adenocarcinomas of the pancreas, but molecular comparisons of these tumor types have previously been impaired by technical difficulties. Recently, immunohistochemical labeling for the DPC4 gene product has been shown to be an extremely sensitive and specific marker for DPC4 gene alterations in pancreatic adenocarcinomas. Therefore, we analyzed the immunohistochemical expression of Dpc4 protein in 79 IPMNs using a previously characterized monoclonal antibody. Twenty-nine of the IPMNs also had an associated infiltrating adenocarcinoma available for analysis. The labeling patterns observed were compared to those we have previously reported for conventional ductal carcinomas. All 79 of the intraductal components of the IPMNs strongly expressed Dpc4 protein. In 77 of the 79 cases (97%), the labeling was diffusely positive, and in 2 of the 79 (3%) the labeling was focally positive. Dpc4 expression was seen in 28 (97%) of the associated 29 invasive cancers. The one infiltrating carcinoma that showed loss of Dpc4 expression was associated with an intraductal component which showed focal loss of Dpc4 expression. The strong and almost universal expression of Dpc4 in IPMNs contrasts sharply with the loss of Dpc4 expression seen in approximately 30% of in situ adenocarcinomas of the pancreas (so-called pancreatic intraepithelial neoplasms, grade 3; P < 0.001) and in 55% of pancreatic duct carcinomas (P < 0.0001). Differences in Dpc4 expression between IPMNs and ductal carcinomas suggest a fundamental genetic difference in tumorigenesis, which may relate to the significantly better clinical outcomes observed for IPMNs.

DPC4 (MADH4, SMAD4) is a tumor suppressor gene inactivated by allelic loss in approximately 55% of pancreatic adenocarcinomas. Unfortunately, it can be technically very difficult to detect the inactivation of DPC4 at the genetic level because genetic analyses require the microdissection of relatively pure samples of neoplastic and normal tissues. This is especially true for pancreatic adenocarcinomas, which elicit vigorous, non-neoplastic, stromal responses. Immunohistochemical labeling can overcome this hurdle because it preserves morphological information. We therefore studied the expression of the DPC4 gene product in 46 cancers, including 5 cancer cell lines by Western blot analysis and 41 primary periampullary adenocarcinomas by immunohistochemistry. The status of exons 1-11 of the DPC4 gene in all 46 of the cancers had been previously characterized at the molecular level, allowing us to correlate Dpc4 expression directly with gene status. Three cell lines had wild-type DPC4 genes, and Dpc4 expression was detected in all three by Western blot. The two cell lines with homozygously deleted DPC4 genes did not show Dpc4 protein by Western blot analysis. Immunohistochemical labeling revealed that 17 (94%) of the 18 primary adenocarcinomas with wild-type DPC4 genes expressed the DPC4 gene product, whereas 21 (91%) of 23 primary adenocarcinomas with inactivated DPC4 genes did not. Cases in which there was discordance between the immunohistochemical labeling and the genetic analyses were reanalyzed genetically, and we identified a deletion in exon 0 of DPC4 in one of these cases. This is the first report of a mutation in exon 0 of DPC4 in a pancreatic cancer. The contrast between the strong expression of Dpc4 by normal tissues and the loss of expression in the carcinomas was highlighted in several cases in which an infiltrating cancer was identified growing into a benign duct. These observations suggest that immunohistochemical labeling for the DPC4 gene product is an extremely sensitive and specific marker for DPC4 gene alterations in pancreatic carcinomas. The sensitivity and specificity of immunohistochemical labeling for Dpc4 in other periampullary carcinomas has yet to be determined.

Purpose We reviewed the long-term local tumor control in patients with bilateral Wilm's tumor (BWT) who received no definitive surgical therapy to one kidney after complete radiographic resolution after initial chemotherapy. Methods National Wilm's Tumor Study 4 (NWTS-4) enrolled 3335 patients (pts) during the period August 1986 to August 1994. There were 188 pts with BWT or 5.6% of the total enrolled. The treatment records and imaging reports were reviewed to ascertain those children who had documented tumors without definitive surgical therapy after initial treatment. Patients who did not have renal surgery because of progression of tumor were excluded from this study. Results Eleven children had no definitive surgical treatment of renal lesions in one kidney (right, 6; left, 5) after initial treatment with chemotherapy and/or radiation therapy. The pretreatment size of the lesions were less than 3 cm (4 pts), 3 to 6 cm (5 pts), more than 6 cm (1 pt), and unknown (1 pt). Prechemotherapy biopsy was performed in 6 of 11 patients. Lesions were less than 3 cm (1 pt), 3 to 6 cm (3 pts), more than 6 cm (1 pt), and unknown (1 pt). Four biopsy specimens showed favorable Wilm's histologic findings. One lesion (4 cm) showed an intralobar nephrogenic rest, another lesion of unknown size was read as favorable histologic findings vs perilobar nephrogenic rest. Biopsy was not performed on 5 lesions (4 pts, Only 2 children in this study received radiation treatment. One child received 1050 cGy whole abdominal radiation, and 1 child received 1060 cGy to the left flank postnephrectomy. Radiation therapy was not given to any patient because of failure of the tumor to respond to chemotherapy. Five patients received treatment regimen EE-4A, dactinomycin, and vincristine. The duration of therapy ranged from 24 to 102 weeks for an average of 55.6 weeks. Three patients received treatment regimen DD-4A, dactinomycin, vincristine, and doxorubicin for 28, 52, and 52 weeks, respectively. Three patients received 2 separate regimens of chemotherapy. One child was treated with dactinomycin, vincristine, and cyclophosphamide for 60 weeks and then received regimen EE-4A for 24 weeks. Another patient received regimen EE-4A for 16 weeks and then regimen DD4-A for 36 weeks. One child received regimen EE-4-A for 12 weeks and then regimen DD4A for 40 weeks. Management of the contralateral kidney was complete nephrectomy in all 11 patients. There were no local relapses in the renal tumor bed. All patients were alive at a median follow-up of 9 years (range, 9 months to 15 years). Conclusion Children with synchronous BWT or Wilm's tumor and contralateral nephrogenic rests that have radiographic resolution, after initial treatment, have a low risk for local relapse. These children should be followed by serial imaging.

OBJECTIVE To characterize the status of the mammalian target of rapamycin pathway using formalin-fixed, paraffin-embedded specimens from patients with primary and metastatic pheochromocytoma. METHODS Tissue microarrays were built from 19 normal adrenal medullas, 39 primary pheochromocytomas, and 8 unrelated metastatic pheochromocytomas. In 2 of the 8 cases of metastatic pheochromocytoma tissues, samples from the primary tumor were available. The expression levels of phosphatase and tensin homolog, phosphorylated Akt, phosphorylated S6, p27, and c-myc were evaluated by immunohistochemistry. RESULTS The levels of phosphatase and tensin homolog and p27 were greater in the nontumor tissue than in the primary and metastatic pheochromocytomas. Increasing levels of phosphorylated Akt were noted in the nontumor adrenal medulla, primary pheochromocytomas, and metastatic pheochromocytomas. Finally, the levels of phosphorylated S6 were greater in the metastatic pheochromocytomas than in the nontumor adrenal medulla and primary pheochromocytomas. CONCLUSION We found evidence of dysregulation of the mammalian target of rapamycin pathway in primary and metastatic pheochromocytomas, with increased phosphorylated S6 and phosphorylated Akt, and decreased phosphatase and tensin homolog and p27 expression levels. Because the currently available treatment modalities are less than optimal, our findings lend additional support to continuing to explore the utility of mammalian target of rapamycin pathway-targeted therapy for pheochromocytomas. UROLOGY 80: 736.e7‐736.e12, 2012. © 2012 Elsevier Inc.

Objectives Collecting duct carcinoma (CDC) is a rare and aggressive renal tumor with a tendency to involve the renal sinus. CDC displays variable morphologic features that can overlap with those of renal medullary carcinoma. The loss of SMARCB1 / INI1 tumor suppressor gene, initially found in pediatric malignant rhabdoid tumors of the central nervous system, kidneys, and soft tissues, was also recently described in renal medullary carcinoma. The current immunohistochemical study assessed SMARCB1/INI1 expression in a series of CDCs. Methods A total of 20 archival cases of CDC were used to construct a tissue microarray. Each tumor was spotted 3-7 times; benign tissue from the same specimen was also included when available. The immunoexpression of SMARCB1/INI1 was evaluated using BAF47, a monoclonal mouse antibody directed against the SMARCB1 / INI1 gene product. Nuclear staining was considered as indicative of SMARCB1/INI1 expression. Results The complete loss of SMARCB1/INI1 expression was observed in 3 of 20 cases of CDC. Another 3 cases revealed focal and weak intensity staining. The remaining tumors showed multifocal or diffuse SMARCB1/INI1 expression with variable staining intensity. No significant differences were found in the clinicopathologic and outcome features regarding SMARCB1/INI1 status. Conclusions The complete loss of SMARCB1/INI1 immunoexpression was found in 15% of CDC. No differences were found between the SMARCB1/INI1 positive and negative cases regarding the clinicopathologic and outcome features. Our results suggest that some CDC cases might be associated with genetic alterations involving the SMARCB1/INI1 gene. In addition, SMARCB1/INI1 immunoexpression seems to be of limited value in the differential diagnosis of CDC versus renal medullary carcinoma, although these results require additional validation.

A recently described subtype of renal cell carcinoma (RCC) bearing chromosome translocations involving a breakpoint at Xp11 and resulting in gene fusions involving the TFE3 transcription factor gene often presents in the pediatric population. Herein we describe an Xp11 translocation RCC associated with prior exposure to cytotoxic chemotherapy, which massively recurred and led to the patient’s death 17 years later. This case highlights the association of these RCCs with prior chemotherapy exposure, the tendency of these RCCs to recur late, their unusual pattern of metastases, and the utility of TFE3 immunohistochemistry in confirming their diagnosis in archival pathologic specimens.