Collecting duct carcinoma of the kidney

A magnetic phantom technique for investigating structural effects on quantitative ultrasound parameters

Media that contain ultrasound scatterers arranged in a regular spatial distribution can be considered as structured. Structural effects affect quantitative ultrasound parameters that reflect the microstructure properties. Prior studies examined structural effects using simulations or phantoms with fixed microarchitecture, focusing on a limited set of ultrasound parameters, with limited attention given to their underlying physical significance. This study aims to investigate the concordance of the physical interpretations of multiple quantitative ultrasound parameters experimentally by introducing a phantom type with an adjustable microarchitecture. The phantom consists of an aqueous solution containing superparamagnetic microspheres, acting as scatterers. The spatial arrangement of the magnetic particles is modified by applying an external magnetic field, therefore changing the degree of structure of the phantom. Quantitative ultrasound parameters are estimated in three different configurations: the magnetic field intensity is varied over time, strength, and orientation. In each experiment, the backscatter coefficient and the envelope quantitative ultrasound parameters are successfully extracted (R2 ≈ 0.94). Their physical interpretations are supported by microphotographs and geometrical considerations through concordant hypotheses. This study paves the way for the use of magnetic phantoms. This methodology could be followed to validate theoretical scattering models and the physical meanings of quantitative ultrasound parameters.

A Rare Case of Collecting Duct Carcinoma With Extensive Coagulative Necrosis

Collecting duct carcinoma (CDC) is an aggressive renal malignancy with limited diagnostic and therapeutic consensus. We report a case of a 69-year-old male with CDC and extensive coagulative necrosis who presented with lower extremity swelling, abdominal distention, and an enlarged left kidney causing grade IV hydronephrosis. Initial treatment with a left percutaneous nephrostomy was followed by clinical deterioration and a diagnosis of emphysematous pyelonephritis. Pathological examination of drainage material revealed extensive coagulative necrosis and was suggestive of a necrotic neoplasm. Subsequent left nephrectomy confirmed CDC with high-grade features, stromal desmoplasia, and extensive coagulative necrosis. Immunohistochemistry studies supported the diagnosis. This study highlights the diagnostic complexity of CDC and emphasizes the need for accurate reporting of atypical presentations. CDC remains a formidable clinical entity with limited treatment options and poor outcomes. Further research is essential to enhance our understanding and management of this rare and aggressive renal malignancy.

Update in collecting duct carcinoma: Current aspects of the clinical and molecular characterization of an orphan disease

Collecting duct renal cell carcinoma (cdRCC), which until recently was thought to arise from the collecting ducts of Bellini in the renal medulla, is a rare and aggressive type of non-clear renal cell carcinoma (ncRCC), accounting for 1% of all renal tumors and with nearly 50% of patients being diagnosed with Stage IV disease. The median overall survival in this setting is less than 12 months. Several regimens of chemotherapies had been used based on morphologic and cytogenetic similarities with urothelial cell carcinoma described previously, although the prognosis still remains poor. The use of targeted therapies also did not result in favorable outcomes. Recent works using NGS have highlighted genomic alterations in SETD2, CDKN2A, SMARCB1, and NF2. Moreover, transcriptomic studies have confirmed the differences between urothelial carcinoma and cdRCC, the possible true origin of this disease in the distal convoluted tubule (DCT), differentiating from other RCC (e.g., clear cell and papillary) that derive from the proximal convoluted tubule (PCT), and enrichment in immune cells that may harbor insights in novel treatment strategies with immunotherapy and target agents. In this review, we update the current aspects of the clinical, molecular characterization, and new targeted therapeutic options for Collecting duct carcinoma and highlight the future perspectives of treatment in this setting.

Integrative Transcriptomic Analysis Reveals Distinctive Molecular Traits and Novel Subtypes of Collecting Duct Carcinoma

Collecting duct carcinoma (CDC) is a rare and highly aggressive kidney cancer subtype with poor prognosis and no standard treatments. To date, only a few studies have examined the transcriptomic portrait of CDC. Through integration of multiple datasets, we compared CDC to normal tissue, upper-tract urothelial carcinomas, and other renal cancers, including clear cell, papillary, and chromophobe histologies. Association between CDC gene expression signatures and in vitro drug sensitivity data was evaluated using the Cancer Therapeutic Response Portal, Genomics of Drug Sensitivity in Cancer datasets, and connectivity map. We identified a CDC-specific gene signature that predicted in vitro sensitivity to different targeted agents and was associated to worse outcome in clear cell renal cell carcinoma. We showed that CDC are transcriptionally related to the principal cells of the collecting ducts providing evidence that this tumor originates from this normal kidney cell type. Finally, we proved that CDC is a molecularly heterogeneous disease composed of at least two subtypes distinguished by cell signaling, metabolic and immune-related alterations. Our findings elucidate the molecular features of CDC providing novel biological and clinical insights. The identification of distinct CDC subtypes and their transcriptomic traits provides the rationale for patient stratification and alternative therapeutic approaches.

'Hybrid' oncocytoma: collecting duct (Bellini) carcinoma-the peril from this extremely rare intratumoural coexistence

We presented an extremely rare entity of 'hybrid' oncocytoma and collecting duct (Bellini) carcinoma. The intratumoural coexistence of benign and malignant cells may lead to false diagnosis and suboptimal treatment of an aggressive tumour. Diagnosis may be challenging if only based on imaging modalities. Even the established value of targeted renal biopsy may be questioned in such scarce cases. Consequently, active surveillance for small renal tumours shall not considered a widely safe management.

Comprehensive genomic profiling of metastatic collecting duct carcinoma, renal medullary carcinoma, and clear cell renal cell carcinoma

INTRODUCTION AND OBJECTIVE

Unlike clear cell renal cell carcinoma (CCRCC), collecting duct carcinoma (CDC) and renal medullary carcinoma (RMC) are rare tumors that progress rapidly and appear resistant to current systemic therapies. We queried comprehensive genomic profiling to uncover opportunities for targeted therapy and immunotherapy.

MATERIAL AND METHODS

DNA was extracted from 40 microns of formalin-fixed, paraffin-embedded specimen from relapsed, mCDC (n = 46), mRMC (n = 24), and refractory and metastatic (m) mCCRCC (n = 626). Comprehensive genomic profiling was performed, and Tumor mutational burden (TMB) and microsatellite instability (MSI) were calculated. We analyzed all classes of genomic alterations.

RESULTS

mCDC had 1.7 versus 2.7 genomic alterations/tumor in mCCRCC ( = 0.04). Mutations in VHL (P < 0.0001) and TSC1 (P = 0.04) were more frequent in mCCRCC. SMARCB1 (P < 0.0001), NF2 (P = 0.0007), RB1 (P = 0.02) and RET (P = 0.0003) alterations were more frequent in mCDC versus mCCRCC. No VHL alterations in mRMC and mCDC were identified. SMARCB1 genomic alterations were significantly more frequent in mRMC than mCDC (P = 0.0002), but were the most common alterations in both subtypes. Mutations to EGFR, RET, NF2, and TSC2 were more frequently identified in mCDC versus mRMC. The median TMB and MSI-High status was low with <1% of mCCRC, mCDC, and mRMC having ≥ 20 mut/Mb.

CONCLUSION

Genomic alteration patterns in mCDC and mRMC differ significantly from mCCRCC. Targeted therapies for mCDC and mRMC appear limited with rare opportunities to target alterations in receptor tyrosine kinase and MTOR pathways. Similarly, TMB and absence of MSI-High status in mCDC and mRMC suggest resistance to immunotherapies.

Collecting ducts carcinoma: An orphan disease. Literature overview and future perspectives

Collecting ducts carcinoma (CDC) is a rare and aggressive histological subtype of renal cancer accounting for only 1% of renal tumors. Usually patients present in bad clinical conditions due to a symptomatic disease with synchronous metastasis. Due to the rarity of CDC, data from prospective trials evaluating the best treatment for these patients are limited. The prognosis is poor with a median overall survival of around 11 months for patients with metastatic disease. The best treatment option today is considered a doublet chemotherapy with platinum salt plus gemcitabine as a result from a prospective phase II trial, but survival outcomes remain unsatisfactory. The interest in the in-depth understanding the biology of this orphan disease is growing, leading to find potential new biological-driven treatment approaches. Here we review the up-to-date literature evidences to address the best management of this rare and unfavorable clinical condition.

A Renal Cancer with Intermediate Characteristics between Collecting (Bellini) Duct Carcinoma and Urothelial Carcinoma: Case Report and Review of the Literature

Collecting duct carcinoma of the kidney is a rare and aggressive neoplasm of the distal collecting tube, often metastatic at the time of the diagnosis, for which there is no established therapy. We herein describe the case of a 65-year-old man with a renal cancer with a particular immunohistochemical pattern and pathologic aspect. The lesion was diagnosed as a tumor borderline between a urothelial carcinoma with intraductal spreading and a collecting duct carcinoma with caly-ceal and pelvic spreading. The patient is disease-free 11 months after diagnosis, after radical surgery with adjuvant chemotherapy (carboplatine and gemcitabine) and radiotherapy of a local recurrence. Owing to the common embryologic origin of collecting duct and transitional urothelial cells, several authors have reported an association between collecting duct carcinoma and urothelial cancer. The literature is reviewed to evaluate drugs active against urothelial cancer (like ifosfamide, paclitaxel, carboplatin and gemcitabine). This field should be investigated in the future, in the framework of a neoadjuvant or adjuvant chemotherapy able to support radical surgery for local and advanced collecting duct carcinoma.

Collecting duct carcinoma kidney masquerading as hydatid cyst: A rare case report and review of literature

Cystic renal masses pose diagnostic challenge especially when they belong to Bosniak Type II and III. Septal and nodular enhancement on computed tomography (CT) is the strongest predictor of malignant process. A unilocular cyst with a calcified rim or a multilocular cystic lesion with heterogeneity on CT goes in favor of hydatid disease. We report a case in a 65-year-old female who presented with painless hematuria, was found to have a cystic mass in the right kidney. The mass turned out to be collecting duct carcinoma after histopathological examination though imaging studies were in favor of a hydatid cyst.

Carcinoma dei Dotti Collettori del Bellini: Case Report con Metastasi Cutanea Come Iniziale Manifestazione Clinica

Introduction

Bellini's collecting ducts carcinoma represents a rare tumor with an aggressive behaviour with a poor prognosis and often metastatic at diagnosis. We report the first case documented of Bellini tumor with an initial clinic presentation represented by a cutaneous metastasis of scalp.

Materials and Methods

All pertinent clinical information were compiled, including patient age, sex, mode of presentation, preoperative laboratory data, radiologic findings, surgery type, macro and microscopic findings, survival data.

Results

After reporting an histopathologic finding of cutaneous metastasis of unknown origin adenocarcinoma with poorly differentiation, a voluminous 6 cm left mesorenal mass is diagnosed through uro-CT. Consequently, it is performed a left radical transperitoneal nephrectomy with consensual exeresis of scalp cutaneous lozenge at the level of previous excision. The histopathologic diagnosis reported was Bellini tumor at stage pT3a-N2-M1. It has not reported significative responsiveness to adjuvant chemotherapy and the patient was died seven months after diagnosis of cutaneous metastasis.

Conclusions

Most of Bellini's carcinoma are already metastatic at presentation. Analiyzing literature, it is never documented a cutaneous metastasis as first sign at clinical presentation. In this context, radical nephrectomy, differently from others subtypes of advanced renal cell carcinoma, does not seem to improve survival of the patient but rather, it can keep a role in palliation or in the context of new chemotherapeutic protocols.

[Bellini duct carcinoma: a new case study and literature review]

Bellini duct carcinoma is a very rare type of renal cell carcinoma (RCC), accounting for less than 1%. It arises from the distal nephron, more specifically from the collecting duct. Its morphological features are extremely variable, making its diagnosis difficult. We report the case of a 62-year old patient admitted with a painless progressive left flank swelling. CT scan showed a huge mass occupying the upper portion of the left kidney. The patient underwent radical nephrectomy. Anatomopathological examination showed collecting duct carcinoma of the kidney. Patient's evolution was exceptionally favorable: no recurrence, no locoregional metastasis and no distant metastasis.

Collecting duct carcinoma of the kidney: Disease characteristics and treatment outcomes from the National Cancer Database

OBJECTIVE

To use a large population-level database to assess survival outcomes for collecting duct renal cell carcinoma (CDRCC).

MATERIALS AND METHODS

The National Cancer Database was queried for all cases of CDRCC and clear cell renal cell carcinoma (CCRCC) from 2004 to 2013. After removing patients with other cancer diagnoses, the analytic cohort was composed of 201,686 CCRCC and 577 CDRCC cases. Kaplan-Meier and cox proportional hazards analysis were employed to model survival.

RESULTS

Compared to CCRCC, patients with CDRCC presented with higher grade and stage, node positive, and metastatic disease (70.7% vs. 30.0% with metastasis; P<0.001). Overall median survival for CDRCC was 13.2 months (95% CI: 11.0-15.5) compared to the 122.5 months (95% CI: 121.0-123.9) for CCRCC. On multivariate analysis of the CDRCC cohort, increasing T stage, high-grade disease, and metastasis were predictors of mortality. Of 184 patients with metastatic CDRCC, 113 underwent cytoreductive nephrectomy (CNx) whereas the rest were treated with chemo/radiation or observed. Survival outcomes were improved in patients who received both CNx with chemo/radiation compared to CNx alone (hazard ratio = 0.51, 95% CI: 0.32-0.79) or chemo/radiation alone (hazard ratio = 0.57, 95% CI: 0.37-0.89) on multivariate analysis.

CONCLUSION

CDRCC is an aggressive subtype of renal cell carcinoma. Median survival is 13 months after diagnosis, drastically lower than for CCRCC. More than 70% of patients have metastatic disease at diagnosis. Chemo/radiation in addition to CNx is associated with a survival benefit over single mode therapy.

Collecting duct carcinoma of the kidney: A case report

Collecting duct carcinoma (CDC) is a rare type of renal tumor, arising from the distal collecting ducts. The prognosis of this disease is extremely poor due to its rapid progression with widespread metastases. The present study reported a case of CDC involving the right renal region of a 62-year-old female patient, presented with right-flank pain that had persisted for one month. A computed tomography scan demonstrated multiple hypoattenuating quasicircular lesions, 0.5-4.3 cm in size, in the upper pole of the right kidney. Following the diagnosis of a right renal tumor, laparoscopic radical resection of the right kidney was performed. Pathological examination demonstrated that the tumor cells were arranged in a glandular or papillary pattern, and marked cytological atypia was observed. Immunohistochemical staining revealed that the tumor cells were positive for epithelial membrane antigen and cytokeratin (CK)7, while they reacted focally with vimentin. However, the tumor cells were negative for CK20, CD10, uroplakin III and p63. Based on these findings, the patient was diagnosed with CDC. In conclusion, immunohistochemical analysis is critical in establishing an accurate diagnosis of CDC and distinguishing this tumor from other subtypes of RCC.

Understanding pathologic variants of renal cell carcinoma: distilling therapeutic opportunities from biologic complexity

CONTEXT

Once believed to represent a uniform malignant phenotype, renal cell carcinoma (RCC) is now viewed as a diverse group of cancers that arise from the nephron.

OBJECTIVE

To review the pathologic characteristics, clinical behavior, molecular biology, and systemic therapy options of recognized RCC histologic subtypes.

EVIDENCE ACQUISITION

A systematic review of English-language articles was performed using the Medline and Web of Science databases. Manuscripts were selected with consensus of the coauthors and evaluated using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria.

EVIDENCE SYNTHESIS

The major findings of the evaluated manuscripts are discussed with an emphasis on the description of the pathologic features, clinical behavior, prognosis, and therapeutic strategies.

CONCLUSIONS

Classification schemes for kidney cancer have undergone dramatic changes over the past two decades. Improvements in these classification schemes are important, as pathologic variants differ not only in disease biology, but also in clinical behavior, prognosis, and response to systemic therapy. In the era of genomic medicine, further refinements in characterization of RCC subtypes will be critical to the progress of this burgeoning clinical space.

PATIENT SUMMARY

Kidney cancer can be subdivided into related but different cancers that arise from the kidney's tubules. In this article we review current classifications for kidney cancer, discuss their characteristics, and provide an overview of each subtype's clinical behavior and treatment. We stress that each subtype harbors unique biology and thus responds differently to available treatment strategies.

Clinical features and treatment of collecting duct carcinoma of the kidney from the korean cancer study group genitourinary and gynecology cancer committee

Purpose

Collecting duct carcinoma (CDC) of the kidney is an aggressive disease with a poor prognosis, accountings for less than 1% of all renal cancers. To date, no standard therapy for CDC has been established. The aim of this study is an investigation of clinicopathologic findings of CDC and correlation of the disease status with a prognosis.

Materials and Methods

From 1996 to 2009, 35 patients with CDC were treated at eight medical centers. The diagnosis of CDC was made based on nephrectomy in 27 cases and renal biopsy in eight cases.

Results

Median PFS and OS for all patients were 5.8 months (95% CI 3.5 to 9.2) and 54.4 months (95% CI 0 to 109.2), respectively. The OS of patients with Stages I-III was 69.9 months (95% CI 54.0 to 85.8), while that of patients with Stage IV was 8.6 months (95% CI 0 to 23.3), which showed a statistically significant difference (p=0.01). In addition, among patients with Stage IV, the OS of patients who received a palliative treatment (immunotherapy, chemotherapy, or targeted therapy) was 18.4 months, which was higher than the OS of patients without treatment of 4.5 months.

Conclusion

CDC is a highly aggressive form of renal cell carcinoma. Despite most of the treatments, PFS and OS were short, however, there were some long-term survivors, therefore, conduct of additional research on the predictive markers of the several clinical, pathological differences and their treatments will be necessary.

Treatment of collecting duct carcinoma: current status and future perspectives

BACKGROUND

Chemotherapy for collecting duct carcinoma (CDC) has demonstrated only limited efficacy in the advanced setting. The present study evaluated the activity of targeted therapies in metastatic CDC.

PATIENTS AND METHODS

We evaluated a cohort of 384 consecutive patients with metastatic renal cell carcinoma (mRCC). The characteristics of patients with CDC were compared against those of the remaining cohort. All patients with CDC were treated with targeted therapies.

RESULTS

Thirteen patients with advanced CDC were referred to our Center (incidence: 3.4% of all mRCC). Median age was 57 and 62 years in the CDC and non-CDC groups, respectively. The overall disease control in the CDC population was 23%, and median overall survival was 4 (95% confidence interval(CI)=2.4-5.6) months. Three patients obtained a satisfying response (disease control lasting 6-33 months).

CONCLUSION

CDC has a poor prognosis compared to non-CDC renal cell carcinoma. Treatment for CDC represents a future challenge and targeted therapies may play a role in selected cases.

Collecting Duct Carcinoma of the kidney: A case report with variable immunohistochemistry

BACKGROUND

Collecting duct carcinoma of the kidney is a rare tumour with distinctive clinical and histopathological features. Management of this malignancy remains a challenge because of advanced stage at presentation and aggressive clinical course.

AIMS

We describe a case of Collecting Duct Carcinoma with variable immunohistochemistry and review the pathology and management.

RESULTS

Our patient died shortly after commencing systemic chemotherapy.

CONCLUSION

Advances in immunohistochemistry have aided in diagnosis of this tumour. Early detection and nephrectomy offer the best chance of cure. Newer chemotherapeutic regimens may improve survival in more advanced disease.

Collecting duct carcinomas represent a unique tumor entity based on genetic alterations

Collecting duct carcinoma (CDC) is a rare renal neoplasm that is associated with poor prognosis due to its highly aggressive course and limited response to immuno- or chemotherapy. Histologically, CDC is defined as a subtype of renal cell carcinomas, but in some cases, it is difficult to differentiate from urothelial carcinomas (UC). Therefore the aim of this study was to determine genetic alterations of CDC in comparison to that of urothelial carcinomas of the upper urinary tract (UUT-UC) to clarify the histological origin of this rare tumor entity. Twenty-nine CDC samples were obtained from seven different German centers and compared with twenty-six urothelial carcinomas of the upper urinary tract. Comparative genomic hybridization (CGH) was used to investigate the genetic composition of patients’ tumors and allowed the detection of losses and gains of DNA copy numbers throughout the entire genome. The clinical data were correlated with CGH results. CGH analysis of CDC revealed DNA aberrations in many chromosomes. DNA losses were more frequently observed than gains, while high-level amplifications were not detected. The mean frequency of CDC chromosomal aberrations (4.9/case) was slightly lower than that in UUT-UC (5.4/case). Recurrent CDC DNA losses occurred at 8p (n=9/29), 16p (9/29), 1p (n=7/29) and 9p (n=7/29), and gains occurred in 13q (n=9/29). In contrast to CDC, the most frequently detected UUT-UC DNA aberration was a loss at 9q (n=13/26). DNA losses at 9q, 13q and 8q as well as gains at 8p showed significant variations in UUT-UC compared to CDC. There was no correlation between the patients’ clinical course and the presence or absence of these recurrent genetic alterations. CDCs are characterized by a different genetic pattern compared to UUT-UC. Regarding the published data on renal cell carcinoma, we conclude that CDC appears to be a unique entity among kidney carcinomas.

Renal collecting duct carcinoma with extensive coagulative necrosis mimicking anemic infarct: report of a case and the literature review

Collecting duct carcinoma (CDC) with a mass of coagulative necrosis is very rare. We report here a case of CDC with extensive geographic coagulative necrosis mimicking anemic infarct with tumor cells embedded around the necrotic foci in a 73-years-old man. Histopathological examination showed that tumor nests near the necrotic foci were arranged as angulated tubules, tubulopapillary and glandular structures. Neoplastic cells had moderate to abundant eosinophilic cytoplasm and large hyperchromatic nuclei with prominent nucleoli as Fuhrman nuclear grade 3 or 4. The tumor cells were positive for pan-Cytokeratin, Vimentin, E-cadherin, CD10, and CK7, confirming the diagnosis as CDC. The patient is still alive 6 months later from nephrectomy, a long time following up is needed to learn the prognosis. Conclusively, morphology from different portions of the lesion, immunohistochemical stain and the combination analysis of the radiological features is essential to make a precise pathological diagnosis of CDC. And CDC should also be distinguished from clear cell renal cell carcinoma, renal medullary carcinoma, urothelial carcinoma with glandular differentiation, renal neuroendocrine tumor, renal epithelioid angiomyolipoma, renal pigmented paraganglioma and renal mesenchymal chondrosarcoma etc.

Management of renal collecting duct carcinoma: a systematic review and the McMaster experience

INTRODUCTION

Collecting duct carcinoma (cdc) is a rare, aggressive form of renal carcinoma that presents at an advanced stage and has a poor prognosis. Little is known concerning the optimal management of cdc. We present the results of a systematic review addressing the management of cdc and the McMaster University cdc series.

METHODS

The medline, Cochrane Library, and embase databases and conference proceedings were searched to identify studies relating to the management of cdc. Included studies reported on a minimum of 10 subjects receiving a single intervention. Series in which an evaluation of therapeutic effectiveness was not possible were excluded. The McMaster University (Hamilton, Ontario) series of 6 cases of cdc were retrospectively reviewed.

RESULTS

We identified 3 studies relevant to the management of cdc that included a total of 72 patients. A gemcitabine-cisplatin or -carboplatin regimen resulted in a 26% objective response rate in 23 patients with metastatic cdc. Two additional studies indicated that 49 patients treated with immunotherapy achieved no response. In the McMaster series, cytoreductive nephrectomy was performed in 4 of 6 patients. In 2 patients, mvac therapy (methotrexate-vinblastine-doxorubicin-cisplatin) achieved no response. No significant therapeutic complications occurred, but survival was poor (median: 11 months; range: 10-33 months).

CONCLUSIONS

Our review and clinical experience suggest that the current standard of care for metastatic cdc is a gemcitabine-cisplatin regimen.

Collecting duct carcinoma of the kidney: a clinicopathological study of five cases

Objective

To investigate the clinicopathological features of collecting duct carcinoma (CDC) and improve its diagnosis and treatment.

Methods

A retrospective analysis was performed with clinical data including follow-up results of five patients with CDC.

Results

A total of 5 cases, including 4 males and 1 female, were included in this analysis with the average age 54 years (range 42 to 65). Patients mainly suffered from lumbar pain, hematuria, abdominal mass and low grade fever. Four patients underwent radical nephrectomy while another received palliative nephrectomy. Lymph node metastasis occurred in 3 cases and renal hilum fat metastasis happened to 2 other cases. Tumors was located in the renal medulla and presented invasive growth. They had a tubulopapillary architecture with the hobnail-shaped cells protruding into the glandular lumen, and were accompanied by interstitial fibrosis and dysplasia of epithelial cells in collecting ducts adjacent to the tumors. One tumor was staged at AJCC II, two at AJCC III and two at AJCC IV. Postoperative interferon immunotherapy was applied in 2 cases. Patients were followed up for 5 to 18 months and the average survival time was 10 months.

Conclusion

The CDC exhibits special clinicopathological features, high degree of malignancy and poor prognosis. The diagnosis depends on the histopathological examination. Early detection and early surgical treatment are still the main methods to improve the prognosis of patients with CDC.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3702794279387989

Active targeted therapy for metastatic collecting duct carcinoma of the kidney: a case report and review of the literature

Collecting duct carcinoma (CDC) is a rare and aggressive renal cell carcinoma (RCC) with extremely poor prognosis, which has been shown to have a poor response to several kinds of systemic therapy. Targeted agents have greatly changed the therapeutic landscape in advanced RCC. Nonetheless, patients with CDC are always excluded from the prospective trials with targeted therapies due to its rarity. We present a case of metastatic CDC that responded favorably to the multiple tyrosine kinase inhibitor, sorafenib, achieving a partial response in both lungs and retroperitoneal lymph nodes metastases. We also reviewed the limited number of reports of metastatic CDC treated with targeted agents and found that 33.33 % (4/12) of patients had favorable clinical activity. These suggest that targeted therapy should be considered for the treatment of metastatic CDC and its prospective evaluation is encouraged.

Carcinoma of the collecting ducts of Bellini and renal medullary carcinoma: clinicopathologic analysis of 52 cases of rare aggressive subtypes of renal cell carcinoma with a focus on their interrelationship

Carcinoma of the collecting ducts of Bellini and renal medullary carcinoma are rare aggressive neoplasms of putative distal nephron origin. First described in 1949, case reports and review articles constitute a major source of information on collecting duct carcinoma, whereas Davis and colleagues and the pediatric tumor registry have contributed the seminal works on renal medullary carcinoma. Here we present a detailed study of collecting duct carcinoma (n=39) and renal medullary carcinoma (n=13), characterizing these rare neoplasms and analyzing their interrelationship. Both collecting duct carcinoma and renal medullary carcinoma exhibited significant similarities, such as predilection for the right kidney, tumor mass with an epicenter in the renal medulla, and a mean size of 7 cm. Overall, both tumors exhibited a poorly differentiated adenocarcinoma histology with desmoplastic stromal response (100%), inflammatory infiltrate (100%), frequent perinephric extension (collecting duct carcinoma: 97%; renal medullary carcinoma: 83%), lymphovascular invasion (100%), intraluminal mucin (collecting duct carcinoma: 42%; renal medullary carcinoma: 73%), high nuclear grade (97%), overlapping immunoreactivity for Ulex europaeus agglutinin 1 (collecting duct carcinoma: 75%; renal medullary carcinoma:55%), CK7 (collecting duct carcinoma: 44%; renal medullary carcinoma: 71%), and high-molecular weight cytokeratin (collecting duct carcinoma: 26%; renal medullary carcinoma: 29%), and nonimmunoreactivity for Ksp-cadherin. Histologically, collecting duct carcinoma frequently had tubular, tubulopapillary, or irregular glandular architecture, whereas renal medullary carcinoma commonly demonstrated islands of anastomosing tubules and cords forming irregular microcystic spaces. Multiple metastases to the lymph nodes, lung, bone, and liver were observed in both categories at presentation (collecting duct carcinoma: 17%; renal medullary carcinoma: 36%). Only patients with organ-confined small tumors were disease free beyond the median survival time. Differential clinical features between collecting duct carcinoma and renal medullary carcinoma included proclivity for younger male individuals of African ancestry with hemoglobin abnormalities and a shorter median survival of 17 weeks (vs. 44 wk for collecting duct carcinoma) for renal medullary carcinoma. The markedly overlapping clinical features, histology, immunophenotype, metastasis patterns, and uniformly aggressive outcome in collecting duct and renal medullary carcinomas suggest that renal medullary carcinoma is a distinctive clinicopathologic subtype within the entity of collecting duct carcinoma. The extremely poor prognosis and ongoing clinical trials with specific therapeutic protocols argue for their accurate distinction from other renal cell carcinoma subtypes.

[Bellini tumours]

In Europe, renal tumours are 7th in frequency of men cancers. They are rare tumours in 10 to 15% of cases. Collecting ducts carcinomas or Bellini tumours, described for the first time in 1949, are a distinct clinical and pathological entity. They represented 1% of epithelial cancers. Nephrectomy is the treatment of localised cancer. Because of lack of recommendations, usually in clinical practice, treatment is similar to urothelial carcinomas treatments (gemcitabine plus platinium). A 72% of response rate of urothelial carcinoma to association of bevacizumab with platinium and gemcitabine 1st line chemotherapy in metastatic setting was reported. More, cases of responses of metastatic Bellini cancers to antiangiogenic treatments associated to chemotherapy were reported these last years. Bellini cancers have a poor prognostic. Unless the fact that this cancer is aggressive, after nephrectomy, cancer specific survival seems not to be different to those of patients with clear cells renal carcinoma and could be related to latest stage of disease in patients. The evaluation of efficacy of association of bevacizumab to chemotherapy is still going on in this association.

Inhibition of pleural metastasis of collecting duct carcinoma of the kidney by modified cytokine-induced killer cells: A case report and review of the literature

Collecting duct carcinoma (CDC) or Bellini duct carcinoma of the kidney is a rare, but highly aggressive renal epithelial malignancy, with an extremely poor prognosis. Modified cytokine-induced killer (mCIK) cells were injected into the pleural cavity to treat pleural metastasis of CDC. The patient, a 33-year-old male, was admitted to hospital for further treatment for severe pleural metastasis of CDC. We cured the pleural metastasis through intrapleural infusion with mCIK cells. After receiving this innovative treatment, the patient exhibited a positive response: the cough, dyspnea, chest distress and thoracalgia were evidently relieved, while the pleural fluid became clear after exhibiting haematodes and its level decreased significantly. The patient achieved partial success. This novel immunotherapy method is a promising treatment for patients with refractory pleural metastasis.

Effect of collecting duct histology on renal cell cancer outcome

PURPOSE

Collecting duct renal cell carcinoma is a rare entity. Recent surgical series of the condition showed conflicting results. We used an American population based data set to compare the survival experience of patients with collecting duct vs clear cell renal cell carcinoma.

MATERIALS AND METHODS

Cases of collecting duct and clear cell renal cell carcinoma were identified in the Surveillance, Epidemiology and End Results program (2001 to 2005). Demographic and pathological characteristics at diagnosis were compared. Differences in disease specific survival were compared with univariate and multivariate Cox regression analysis.

RESULTS

A total of 160 collecting duct renal cell carcinoma cases were present in the database from 2001 to 2005. In that time 33,252 clear cell renal cell carcinoma cases were diagnosed. Collecting duct renal cell carcinoma was more common in black than in white patients (23% vs 9%, p <0.001). Collecting duct renal cell carcinoma was more commonly T3+ than T2/T1 (33% vs 18%, p <0.001) and metastatic than regional/local (28% vs 17%, p = 0.001). Nephrectomy rates were similar (84% and 78%, p = 0.06). The 3-year disease specific survival rate was 58% and 79% for collecting duct and clear cell renal cell carcinoma, respectively. On multivariate analysis there was an increased mortality risk in patients with collecting duct vs clear cell renal cell carcinoma (HR 2.42, 95% CI 1.72-3.39, p = 0.001).

CONCLUSIONS

Compared to patients with clear cell renal cell carcinoma those with collecting duct renal cell carcinoma have higher stage and are more often black. Even after adjusting for demographic, surgical and pathological factors disease specific survival is significantly worse in patients with collecting duct rather than clear cell renal cell carcinoma. Further research into the biology of this rare tumor is required to explain these results.

Uncommon and recently described renal carcinomas

Major consensus conferences held over a decade ago laid the foundations for the current (2004) WHO classification of renal carcinoma. Clear cell, papillary and chromophobe carcinomas account for 85-90% carcinomas seen in routine practice. The remaining 10-15% of carcinomas consist of rare sporadic and hereditary tumors, some of which had been long recognized, but many of which only emerged as distinct entities in the decade leading up to the WHO publication. Collecting-duct carcinoma is a rare, often lethal form of carcinoma. Medullary carcinoma associated with sickle cell trait, has emerged as a distinctive tumor showing some overlapping features with upper tract urothelial carcinoma. Mucinous tubular and spindle-cell carcinoma and tubulocystic carcinoma were earlier considered as patterns of low-grade collecting-duct carcinoma, but are now recognized as separate tumor entities. Carcinomas associated with somatic translocations of TFE3 and TFEB comprise a significant proportion of pediatric renal carcinomas. Oncocytoid renal carcinomas in neuroblastoma survivors was recognized as a unique tumor category in the WHO classification. Renal carcinoma associated with end-stage renal disease is now recognized as having distinct morphological patterns and behavior. In addition there is a group of rare recently described carcinomas, including clear cell papillary carcinoma, oncocytic papillary renal cell carcinoma, follicular renal carcinoma and leiomyomatous renal cell carcinoma. It behooves the surgical pathologist to not only be capable of diagnosing the common forms of renal cancer, but also to be aware of the rare types of renal carcinoma, many of which have emerged in recent years.

Carcinoma of the collecting ducts of Bellini of the kidney: adjuvant chemotherapy followed by multikinase inhibition with sunitinib

BACKGROUND

Carcinoma of the collecting ducts (CDC) of Bellini of the kidney is very rare but is among the most aggressive urologic entities.

PATIENTS AND METHODS

Radical nephrectomy revealed CDC in stage pT3a pN2 M0 G3 in 2 male patients. Four courses of adjuvant chemotherapy with cisplatin and gemcitabine were given.

RESULTS

Subsequent restaging revealed local recurrence and lymph node metastases. Both patients were operated on again, and metastatic CDC was found. Second-line therapy with sunitinib was administered. After 2 cycles, multiple liver, lung, and bone metastases and mediastinal lymphopathy occurred. Eight weeks later, the patients died, with a survival of 8 months from initial diagnosis.

CONCLUSION

Nephrectomy, adjuvant gemcitabine/cisplatin, and sunitinib therapy did not alter the course of disease in these patients. Gross resection of disease was rapidly followed by local recurrence and, subsequently, widespread dissemination of disease. Clinical trial investigation is urgently needed because of the aggressive and refractory nature of CDC.

Prospective multicenter phase II study of gemcitabine plus platinum salt for metastatic collecting duct carcinoma: results of a GETUG (Groupe d'Etudes des Tumeurs Uro-Génitales) study

PURPOSE

Collecting duct carcinoma of the kidney is a rare and aggressive neoplasm of the distal collecting tubules for which there is no established treatment. Since the histology of collecting duct carcinoma is similar to that of urothelial carcinoma, the standard chemotherapy regimen defined by a gemcitabine and platinum salts combination was prospectively investigated in patients with metastatic collecting duct carcinoma.

MATERIALS AND METHODS

A total of 23 patients with metastatic collecting duct carcinoma with no prior systemic chemotherapy were treated with 1,250 mg/m(2) gemcitabine on days 1 and 8 plus 70 mg/m(2) cisplatin or carboplatin (AUC 5) in patients with renal insufficiency on day 1. The drugs were repeated every 21 days for 6 cycles according to toxicity and efficacy. The objective response rate was the primary end point.

RESULTS

There were 1 complete and 5 partial responses for an objective response rate of 26% (95% CI 8 to 44). Median progression-free and overall survival was 7.1 (95% CI 3 to 11.3) and 10.5 months (95% CI 3.8 to 17.1), respectively. Toxicity was mainly hematological with grade 3-4 neutropenia and thrombocytopenia in 52% and 43% of patients, respectively. The severity of granulocytopenia and the number of metastatic sites were associated with overall survival on univariate and multivariate analyses.

CONCLUSIONS

To our knowledge this is the first prospective, multicenter, phase II study showing that the platinum salts combination is an active and safe regimen as first line treatment in patients with metastatic collecting duct carcinoma. This platinum based chemotherapy should be considered the standard regimen in these patients.

[Collecting duct carcinoma associated with renal stones]

Collecting duct carcinoma is an extremely rare disease, representing less than 1% of all renal tumours. The authors report the case of a 72-year-old patient presenting with right low back pain associated with episodes of total macroscopic haematuria. Imaging showed a heterogeneous mass in the upper pole of the right kidney associated with pyelocaliceal stones. Multiple secondary lesions were observed in the liver. Macroscopically, the mid-renal tumour was 7.5 cm in diameter surrounding the stone-containing pyelocaliceal cavities. This tumour had spread to the cortex and invaded the perirenal fat. Histologically, the tumour was composed of ducts lined by cells with a hobnail appearance in an abundant desmoplastic and neutrophil-rich inflammatory stroma. Immunohistochemistry showed very intense labelling of tumour cells with cytokeratins: KL1, 7, 19, and 34_E12 and slightly less intense labelling with UER, Vimentin, EMA, and BNH9, while cytokeratin 20 was negative. The diagnosis of Fuhrman grade 3 collecting duct carcinoma associated with renal stones and liver metastases was adopted. The patient died postoperatively. The main differential diagnosis was urothelial carcinoma with a glandular component. In the present case, the diagnosis was made more difficult by the concomitant presence of renal stones. The diagnosis was established by histology and immunohistochemistry.

Chemotherapy for non-clear-cell renal cell carcinoma

Clear-cell carcinoma is the most common histopathologic subtype of kidney tumors. Consequently, clinical trials for advanced-stage kidney cancer have focused on patients with clear-cell carcinoma and not on the less common subtypes, including papillary, chromophobe, collecting-duct carcinoma, and sarcomatoid-variant tumors. Whereas immunotherapy has constituted the standard treatment for patients with clear-cell renal cell carcinoma (RCC), it does not appear to have activity in the management of patients with other histologic subtypes. Novel therapies, including those targeting the vascular endothelial growth factor pathway, have recently demonstrated significant activity in clear-cell RCC. Historically, chemotherapy has shown limited activity in advanced-stage RCC; however, clinical trials to date have failed to individualize treatment based on histologic subtype. In this article, we will review the literature and present our experience with the use of chemotherapy in patients with non-clear-cell kidney cancer by histologic subtype.

Collecting duct carcinoma of the renal medulla presenting with paraplegia

We report an interesting case of a patient with collecting duct carcinoma arising from the left kidney who presented with paraplegia secondary to metastases. The diagnosis was based on CT and histology. To our knowledge this is the first case of collecting duct carcinoma to present with paraplegia. The literature review also highlights the rarity of this disease with less than a hundred cases reported to date and the aggressive nature and poor prognosis despite prompt interventions.

Application of molecular diagnostic techniques to renal epithelial neoplasms

The application of molecular and cytogenetic techniques to the study of renal neoplasia has resulted in improved understanding of the biologic mechanisms that are responsible for tumor development and progression. It also revealed that several different and specific genetic events are responsible for tumorigenesis in the various categories and subcategories of renal tumors. The ultimate goal of research on the molecular pathology of renal neoplasms is a complete understanding of the genetics of these tumors, which will, in turn, aid in making the correct diagnosis, accurately assessing prognosis, and selecting appropriate and targeted therapeutic options.

Low-grade renal collecting duct carcinoma. A case report with histochemical, immunohistochemical, and ultrastructural study

We report a rare tumor called low-grade renal collecting duct carcinoma. Grossly, the tumor consisted of multiple cysts and solid white nodules, measuring 10 cm in diameter and occupying most of the renal parenchyma. Histologically, the tumor was characterized by well-differentiated tubules lined by eosinophilic cells without papillary projections, abundant predominantly extracellular mucin, minimal cellular atypia, no desmoplasia, and rare mitoses. This tumor occurs in collecting ducts and the tumor cells were positive for epithelial membrane antigen, high-molecular-weight keratin, CD15, and mitochondrial antibody and negative for CD10. Few cells stained weakly positive for ulex europaeus. Ultrastructural study showed a large number of mitochondria according to the eosinophilic cells seen in light microscopy.

[Low grade collecting duct carcinoma of the kidney. Presentation of one case and literature revision]

Collecting duct renal cell carcinoma is an uncommon variant of renal carcinoma. Typically its behaviour is more aggressive than other forms of renal carcinoma and usually it is diagnosed at advanced stages. A 57-year-old man visited our hospital by right lumbar pain. Abdominal CT showed a enhanced mass on the right kidney. A right partial nephrectomy was done. Histological examination of the surgical specimen showed a low grade collecting duct carcinoma of the kidney. This is a new entity, with unknown behaviour but seems to be less aggressive than classical collecting duct carcinoma of the kidney. The clinical, radiological, pathological and immunohistochemical characteristics of this tumor are reported, and the literature is reviewed.

Collecting duct carcinoma of the kidney: an immunohistochemical study of 11 cases

Background

Collecting duct carcinoma (CDC) is a rare but very aggressive variant of kidney carcinoma that arises from the epithelium of Bellini's ducts, in the distal portion of the nephron. In order to gain an insight into the biology of this tumor we evaluated the expression of five genes involved in the development of renal cancer (FEZ1/LZTS1, FHIT, TP53, P27^kip1, and BCL2).

Methods

We studied eleven patients who underwent radical nephrectomy for primary CDC. All patients had an adequate clinical follow-up and none of them received any systemic therapy before surgery. The expression of the five markers for tumor initiation and/or progression were assessed by immunohistochemistry and correlated to the clinicopathological parameters, and survival by univariate analysis.

Results

Results showed that Fez1 protein expression was undetectable or substantially reduced in 7 of the 11 (64%) cases. Fhit protein was absent in three cases (27%). The overexpression of p53 protein was predominantly nuclear and detected in 4 of 11 cases (36%). Immunostaining for p27 was absent in 5 of 11 cases (45.5%). Five of the six remaining cases (90%) showed exclusively cytoplasmic protein expression, where, in the last case, p27 protein was detected in both nucleus and cytoplasm. Bcl2 expression with 100% of the tumor cells positive was observed in 4 of 11 (36%) cases. Statistical analysis showed a statistical trend (P = 0.06) between loss and reduction of Fez1 and presence of lymph node metastases.

Conclusions

These findings suggest that Fez1 may represent not only a molecular diagnostic marker but also a prognostic marker in CDC.

Bilateral collecting duct carcinoma presenting with tumour associated nephritis and end-stage renal failure. A case report and review of the literature

We present a 55 year old male who was investigated for painless macroscopic haematuria and had essentially normal radiological and cystoscopic findings. He progressed rapidly and was eventually diagnosed with a Collecting Duct Carcinoma. This case is of interest as it is the first reported case of Collecting Duct Carcinoma occurring bilaterally. It is also the first case to cause end stage renal failure requiring dialysis due to extensive tubular involvement. Finally, it is the first time this malignancy has been found to cause a tumour associated nephritis. We describe the clinical course and present the various histological findings followed by a review of the literature.

Collecting Duct Carcinoma of the Kidney: A Clinicopathological Study Of 9 Cases

PURPOSE

Collecting duct carcinoma (CDC) of the kidney is a rare variant that is associated with an extremely poor prognosis. We report our experience with this variety of cancer in the last 9 years.

MATERIALS AND METHODS

From 1993 to 2002, 9 patients with CDC were treated at our institution. The diagnosis of CDC was made by a nephrectomy specimen in 8 cases and by renal biopsy in 1. Tumor characteristics, and patient treatment and outcome are reported.

RESULTS

At presentation 1 T1N0M0, 1 T3N0M0, 3 T3N+M0 and 4 T3N+M+ tumors were seen. Mean followup was 13.6 months. Five patients received no complementary treatment. The patient with the T1N0M0 tumor remained free of disease 13 months after nephrectomy and the one with T3N0M0 tumor remained free of disease at 17 months. A patient with a T3N+M+ tumor experienced progression at 1 month, local recurrence at 17 months and was then lost to followup. The 2 other patients with T3N+M0 and T3N+M+ disease, respectively, progressed rapidly and were lost to followup after 5 months. One patient with a T3N+M0 neoplasm received immunotherapy and died after 24 months, while the other with T3N+M0 disease was treated with oral prednisolone and died after 5 months. Finally, 2 patients with T3N+M+ disease received chemotherapy, consisting of 1,250 mg/m2 gemcitabine on days 1 and 8, and 70 mg/m2 cisplatin on day 1. Each patient achieved an objective response after 3 chemotherapy cycles and remained disease-free 27 and 9 months after nephrectomy, respectively.

CONCLUSIONS

CDC is an aggressive variety of kidney neoplasm that is often associated with nodal and visceral metastases at presentation. Our data suggest that combined gemcitabine and cisplatin chemotherapy may be the best therapeutic option for patients with this tumor.

Bellini duct carcinoma: review of diagnosis and management

AIM

To review the world literature on the histogenesis, diagnosis and management of Bellini duct carcinoma and to suggest a possible clinical algorithm to assist in their identification and appropriate therapeutic strategies.

METHODS

A medline review of all reported cases of Bellini duct carcinoma was carried out from the Pubmed using the keywords collecting duct carcinoma, Bellini duct carcinoma, medullary renal carcinoma and renal cancers.

RESULTS

40 worldwide reported cases of Bellini duct carcinoma were found. We analyzed their salient pathological, diagnostic and management strategies. A simplistic approach and a clinical algorithm has been suggested to enable their rapid identification, diagnosis and management.

The collecting duct carcinoma of the kidney: a cytogenetical study

OBJECTIVES

The Heidelberg classification of renal tumours identifies five histotypes of renal cancer, underlining for two of them (conventional and papillary renal cancers) a strict relation between the morphological aspect and the complement of alterations evidenced by the cytogenetic analysis of the neoplastic karyotype. Due to its low incidence, the collecting duct carcinoma (CDC) has not yet been characterized from a cytogenetic point of view. This study analyses the clinical, morphologic and cytogenetic features of the CDC observed and treated in our department.

METHODS

From January 1995 to December 2002, among the 591 patients who underwent surgery for renal cancer, we observed 11 cases of CDC (prevalence 1.9%) treated either by radical (9 cases) or partial nephrectomy (2 cases). During radical nephrectomy a loco-regional lymphadenectomy was always performed. In the 9 cases observed after 1997, a complete cytogenetic analysis of the neoplastic karyotype was carried out.

RESULTS

At pathological examination the disease was found to be confined to the renal capsule (TNM 1997 stage 1) in only 3 patients; venous neoplastic trombosis and nodal metastasis were present in 3 and 6 cases respectively; 2 patients showed distant metastases (lung, bone). Two of the patients affected with stage 1 tumours are still alive with no evidence of the disease at 48 and 88 months after surgery, while the third died following the systemic progression of a concomitant bladder carcinoma. One patient with stage 4 tumour (no. 11) is alive, but the follow up time is still limited (2 months). All the other 7 patients are dead after a mean survival time of 16.3 months (range 0-45). As for cytogenetic analysis, 2 CDCs didn't grow in culture and in one case no karyotype alterations were reported. In the remaining 6 cases hypodiploid stemlines and a homogeneous chromosome alteration pattern were observed, with multiple numerical and structural aberrations (mean 11.1, range 7-15) and the continuous involvement of chromosomes 1 and X or Y, both as traslocation and deletion/monosomy. Additional abnormalities of chromosomes 22 and 13 were found to be common but less frequent.

CONCLUSIONS

The clinical behaviour of the CDC is aggressive and its prognosis is surely poor; surgical treatment seems to be curative only for organ-confined cancer, accounting for the minority of cases. This neoplasm is cytogenetically characterized by hypodiploid stemlines with common involvement of chromosome 1 and the autosomes.

Is there a place for radical nephrectomy in the presence of metastatic collecting duct (Bellini) carcinoma?

PURPOSE

We describe diagnostic and therapeutic characteristics, and long-term followup of collecting (Bellini) duct carcinoma.

MATERIALS AND METHODS

Ten patients underwent surgery, including radical nephrectomy in 9 and partial nephrectomy in 1, for collecting duct carcinoma diagnosed by histological and immunohistochemical criteria.

RESULTS

Collecting duct carcinoma, which represented 1.3% of renal cell carcinomas diagnosed between 1986 and 1999, developed at a mean patient age of 66.2 years (range: 50.7 to 81). It was detected clinically but never because of macroscopic hematuria. Mean tumor size was 94 mm. (range 30 to 150). Stage was pT3, pT2 and pT1 in 7, 1 and 2 cases, respectively. Seven patients had lymph node or extranodal metastases, and 8 and 2 had Fuhrman grades 3 and 4 disease, respectively. Eight patients died, including 3 early during the perioperative or postoperative period, which was attributable to major surgical difficulties associated with these invasive tumors. Two of the 3 patients who did not have metastases were alive 99 and 100 months after surgery, respectively. Median overall survival +/- SD was 9 +/- 6 and 6 +/- 8 months for patients with metastases. The all survival rate was 20% at 2 years.

CONCLUSIONS

Most collecting duct carcinomas are already metastatic at presentation. Because the prognosis is dismal despite radical nephrectomy, biopsy should be performed first when radiological findings are suggestive of collecting duct carcinoma. For metastatic collecting duct carcinoma radical nephrectomy alone does not seem to be useful except for palliative reasons or in the framework of new multicentric chemotherapy protocols in progress.

Immunohistochemical profile of common epithelial neoplasms arising in the kidney

To distinguish common epithelial tumors arising in the kidney may have significant implications, in terms of molecular ontogeny and prognosis. It is important to investigate the distribution of immunoexpression of commonly used markers among renal neoplasms and to develop a useful panel as an adjunct to histologic examination, which could lead to the accurate diagnosis of both primary and metastatic tumors. Immunohistochemical stains for CD10, vimentin (VIM), E-cadherin (E-CD), cytokeratins (CK) 7, 8, 19, and 20, high molecular weight keratin (HCK), and peanut lectin agglutinin (PL) (Arachis hypogaea) were performed on 45 (96 for CK7, CK20) conventional (CC), 20 papillary (PC), and 6 (24 for CK7, CK20) chromophobe renal carcinomas (CPC); 12 oncocytomas (OC); 5 collecting duct carcinomas (CDC), and 25 urothelial carcinomas of the renal pelvis (UC). Reactivity for CD10 was evaluated on the basis of the presence of cell surface staining; that for all CKs, cytoplasmic/membranous staining; and that for PL, luminal staining. Both CD10 and VIM were predominantly expressed in CC and PC; E-CD in CPC, OC, and UC; CK7 in PC, CPC, and UC; CK8 and CK19 in CDC and UC; CK20 in UC; HCK in CDC and UC; and PL in CDC. CC and OC were predominantly CK7-/CK20-; PC, CK7+/20-; CPC, CK7+/CK20- or CK7-/CK20-; and UC, CK7+/CK20- or CK7+/CK20+. CDC showed slight predominance of CK7-/20- over CK7+/CK20-. CC was most frequently CD10+/CK7-/HCK-/PL-; PC, CD10+/CK7+/HCK-/PL-; CPC, CD10-/CK7+/HCK-/PL-; OC, CD10-/CK7-/HCK-/ PL-; CDC, CD10-/CK7+/HCK-/PL+ or CD10-/CK7-/ HCK+/PL+; and UC, CD10-/CK7+/HCK+/PL-. Discriminant analysis suggested that CD10/CK7/HCK/PL may be a useful primary immunopanel for distinguishing among CC, PC, CDC, and UC.