Clear Cell Papillary Renal Cell Carcinoma: New Clinical and Imaging Characteristics

Diagnostic value of imaging in patients with clear cell papillary renal cell carcinoma: A case series and literature review

Clear cell papillary renal cell carcinoma (CCPRCC) is a newly classified renal cell carcinoma with a low degree of malignancy. Its imaging features have not been studied deeply. Therefore, we reviewed the imaging features of CCPRCC. Solid CCPRCC shows high echo or isoecho mass on conventional ultrasound. Contrast enhanced ultrasound shows "fast forward and slow backward, uneven high enhancement". Computed tomography shows high enhancement and maximum enhancement in the cortical-medullary phase. Magnetic resonance imaging shows slightly low T1WI and high T2WI. This article aims to improve the understanding of CCPRCC by clinical radiologists and promote the accurate.

Clinico-pathological implications of the 2022 WHO Renal Cell Carcinoma classification

The new WHO classification of urogenital tumours published in 2022, contains significant revisions upon the previous 2016 version regarding Renal Cell Carcinoma (RCC). While the most common histotype remains almost untouched, some of the main novelties concerns papillary RCC and oncocytic neoplasms. The main change is the introduction of a new category of molecularly-defined RCC, which includes TFE3-rearranged RCC, TFEB-rearranged, and TFEB-amplified RCC, FH-deficient RCC, SDH-deficient RCC, ALK-rearranged RCC, ELOC (formerly TCEB1)-mutated RCC, SMARCB1 (INI1)-deficient RCC. In this paper we analyze the current knowledge on emerging entities and molecularly-defined RCC to assess whether the current pathological classification offers the oncologist the possibility of selecting more specific and personalized treatments, from both those currently available, as well as those that will soon be available.

Clinical features and Surgical Outcome of Clear Cell Papillary Renal Cell Tumor: result from a prospective cohort

BACKGROUND

Clear cell papillary renal cell tumor (CCPRCT) was first reported in 2006 a patient with end stage renal disease. After that it was discovered in the kidney without end stage renal disease in the 2010s and started to be mentioned in pathology and urology. The incidence of CCPRCT is low and most of it is discovered incidentally, so there is a lack of reports on clinical characteristics and surgical outcome.

METHODS

This study used clinical data from the Seoul National University Prospectively Enrolled Registry for Renal Cell Carcinoma-Nephrectomy (SUPER-RCC-Nx). Between August 2016 and July 2022, patients who underwent radical or partial nephrectomy with clear cell papillary RCC with pathological finding were included in this study. All patients' pathologic reports were reviewed by 1 pathologist. Clinical characteristics and surgical outcomes were presented through descriptive statistics, and Kaplan-Meier curve used for survival analysis.

RESULTS

Of the 2057 patients, CCPRCT was reported in 36 patients (1.8%). The median follow up period was 26.8 months. The median age was 67 years, and there were 10 females and 26 males. The median tumor size was 1.2 cm. Twenty-nine patients underwent partial nephrectomy. Seven patients with end-stage renal disease underwent radical nephrectomy. The median operative time for patients who underwent partial nephrectomy was 97.5 min and the estimated blood loss was 100 cc. The median hospital days was 4 and 30-day complications were 2 cases with clavien-dindo classification III or higher. During the follow-up period, there was no recurrence and cancer specific mortality.

CONCLUSIONS

The size of CCPRCT was small and there was no advanced stage at that time of diagnosis. There was no recurrence or cancer specific mortality during the follow-up period. A multi-center study with a large scale is needed in the future.

TRIAL REGISTRATION

Seoul National University Hospital (SNUH) Institutional Review Board (IRB) (approval number: 2210-126-1371).

Importance of tumor subtypes in cancer imaging

Cancer therapy has evolved from being broadly directed towards tumor types, to highly specific treatment protocols that target individual molecular subtypes of tumors. With the ever-increasing data on imaging characteristics of tumor subtypes and advancements in imaging techniques, it is now often possible for radiologists to differentiate tumor subtypes on imaging. Armed with this knowledge, radiologists may be able to provide specific information that can obviate the need for invasive methods to identify tumor subtypes. Different tumor subtypes also differ in their patterns of metastatic spread. Awareness of these differences can direct radiologists to relevant anatomical sites to screen for early metastases that may otherwise be difficult to detect during cursory inspection. Likewise, this knowledge will help radiologists to interpret indeterminate findings in a more specific manner.

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Tumor subtypes can be identified based on their different imaging characteristics.

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Awareness of tumor subtype can help radiologists chose the appropriate modality for additional imaging workup.

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Awareness of differences in metastatic pattern between tumor subtypes can be helpful to identify early metastases.

Renal Cell Carcinoma in End-Stage Renal Disease: A Review and Update

Renal cell carcinoma (RCC) occurring in the setting of end-stage renal disease (ESRD) shows unique clinicopathological characteristics. The two most frequent types of ESRD-associated RCC are acquired cystic kidney disease-associated renal cell carcinoma (ACKD-RCC) and clear-cell papillary renal cell carcinoma (ccpRCC). Other types of RCC also occur in ESRD, albeit with different frequencies from the non-ESRD general population. The histological features of RCC do not vary in the setting of ESRD vs. non-ESRD, yet other findings, such as multifocality and multiple tumor types, are more frequent in ESRD. Studies have generated novel and important knowledge of the etiology, epidemiology, diagnosis, treatment, immunophenotype, and molecular characteristics of ESRD-associated RCC. Knowledge of these data is important for both pathologists and other physicians who may encounter ESRD patients with RCC. This review presents a comprehensive summary and update of the literature on RCC in ESRD, with a focus on the two most frequent types, ACKD-RCC and ccpRCC.

Clinicopathological features of non-conventional renal cell carcinoma histological subtypes: Learning points from a large contemporary series spanning over three decades

Purpose

To perform a retrospective review of the clinicopathological features of patients with conventional and non-conventional renal cell carcinoma (cRCC and ncRCC).

Materials and Methods

A large prospectively maintained uro-oncological registry was accessed to extract clinicopathological data of patients diagnosed with renal tumors who subsequently underwent nephrectomy from 1990–2019. Demographics and operative parameters were extracted. Analyses of overall survival (OS) and cancer-specific survival (CSS) were performed using the Kaplan–Meier method. Cox proportional-hazards analysis was used to identify risk factors which influenced survival.

Results

There were a total of 1,686 consecutive nephrectomies which was retrieved, with 1,286 cRCC and 400 ncRCC. The commonest ncRCC subtypes were papillary (n=198, 11.7%), clear cell papillary (n=50, 3.0%) and chromophobe (n=49, 2.9%) RCC. Kaplan–Meier estimates of OS were higher in cRCC (0.74; 95% confidence interval [CI], 0.71–0.78) than ncRCC (hazard ratio, 1.47; 95% CI, 1.16–1.87). Among individual subtypes, chromophobe RCC had the highest 5-year OS (0.90; 95% CI, 0.79–1.0). Among ncRCC subtypes, acquired cystic RCC demonstrated the highest association with end-stage renal failure and hypertension, with the highest CSS. MiT family translocation RCC had the youngest mean age at presentation (45.6±12.8 y) and excellent CSS. Factors associated with increased OS in the entire cohort included shorter operative time, partial nephrectomy and lower tumor stages.

Conclusions

This study provides a comprehensive contemporary overview of ncRCCs which are yet poorly characterized, in comparison to cRCCs. Data from this study would contribute towards tailored patient counseling and healthcare resource planning.

Characteristics of Clear Cell Papillary Renal Cell Carcinoma (ccpRCC)

Renal cell carcinomas (RCCs) is a group of various malignant tumours of the renal cortex displaying distinct clinical, morphologic, and genetic features. Clear cell papillary renal cell carcinoma (ccpRCC), belonging to this group, shares morphologic features with both clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC) and therefore, more strict diagnostic criteria should be developed to avoid misdiagnosis. Despite overlapping features, ccpRCC has also distinct clinical behaviour, histologic characteristics (morphologic and immunohistochemical), and genomic features. The concepts concerning this tumour are constantly developing since its biological potential and molecular basis remains to be fully unravelled. First reports indicated the presence of ccpRCC in end-stage renal disease, and they underlined the enriched development in this group of patients; however, currently, it is known that such tumours can also occur spontaneously in the normal kidney. Numerous studies have demonstrated that clinical outcomes and prognosis of ccpRCC patients is highly favourable. Till now, no convincing evidence of metastatic ccpRCC or death caused by the disease has been found. Therefore, it is of high importance to correctly differentiate ccpRCC from other subtypes of RCC with a much worse prognosis and to introduce appropriate management.

New developments in existing WHO entities and evolving molecular concepts: The Genitourinary Pathology Society (GUPS) update on renal neoplasia

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.

The Clinicopathologic and Molecular Landscape of Clear Cell Papillary Renal Cell Carcinoma: Implications in Diagnosis and Management

BACKGROUND

Clear cell papillary renal cell carcinoma (CCPRCC) is a recently described tumor entity. Several questions remain about its epidemiology, molecular features, and clinical behavior.

OBJECTIVE

To comprehensively evaluate clinicopathologic and molecular features of CCPRCC, and compare it with more common kidney cancer subtypes.

DESIGN, SETTING, AND PARTICIPANTS

We identified 89 CCPRCC patients and compared their clinicopathologic features with 1120 localized clear cell renal cell carcinoma (ccRCC) and 129 type 1 papillary renal cell carcinoma (pRCC) patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Nonparametric statistical testing was used to compare relevant features between tumor types. Overall, cancer-specific survival (CSS) and metastasis-free survival estimates were calculated from initial diagnosis using the Kaplan-Meier method. Patients with ipsilateral multifocal disease were explored further. A subset of CCPRCC tumors underwent genomic analysis and were compared with other RCC subtypes.

RESULTS AND LIMITATIONS

A higher proportion of female (45% vs 32%) and African-American (19% vs 3%) patients were observed in the CCPRCC cohort than in the ccRCC and pRCC cohorts. CCPRCC tumors also had increased odds of presenting with additional ipsilateral masses (odds ratio [OR]: 4.41 [confidence interval {CI}: 2.34, 8.15], p < 0.001) and bilateral disease (OR: 4.80 [CI: 2.40, 9.59], p < 0.001) compared with ccRCC tumors. On molecular analysis, CCPRCC tumors showed fewer somatic aberrations and a greater degree of mitochondrial DNA depletion. In multifocal CCPRCC tumors, histologic concordance among the different renal cell carcinoma masses was estimated at 44% (7/16), and none of the individuals presenting exclusively with CCPRCC tumors developed metastatic disease after 5 yr. In contrast, multifocal tumors with CCPRCC and other nonconcordant histologies were more likely to experience adverse outcomes (CSS, log rank p = 0.034).

CONCLUSIONS

CCPRCC is characterized by distinct molecular and epidemiologic features that could be used to refine current diagnostic approaches. Although their clinical course is generally indolent, multifocal CCPRCC tumors represent a unique diagnostic challenge. In this context, single-mass biopsies could miss concomitant aggressive disease, with a potential negative impact on patient outcomes. Furthermore, high discordance rates in multifocal CCPRCC tumors have important clinical implications in management.

PATIENT SUMMARY

We explored the molecular and clinical features of clear cell papillary renal cell carcinoma (CCPRCC) relative to other kidney cancer subtypes. While CCPRCC generally conveys a good prognosis, additional caution should be taken when it is diagnosed using biopsy if multiple kidney masses are present.

Clear cell papillary renal cell carcinoma: Characteristics and survival outcomes from a large single institutional series

OBJECTIVES

To investigate the clinical characteristics and survival outcomes of a large clear cell papillary renal cell carcinoma cohort.

METHODS AND MATERIALS

A retrospective review of patients with clear cell papillary renal cell carcinoma at a single academic center was performed after Institutional Review Board approval. Patients underwent either partial or radical nephrectomy from September 2009 to July 2019. Demographic and clinical characteristics, recurrence, and cancer specific and overall survival were reported.

RESULTS

A total of 90 patients were included in the study. Median follow up was 26.5 months. Median age was 61 (range 27 to 87). 47.8% of patients were African American. 26.7% of patients had end stage renal disease. 37.8% had multifocal renal tumors. 48.9% underwent partial nephrectomy, while the remainder underwent radical nephrectomy. 43.3% underwent an open surgical approach, 40.0% a robotic approach, and 16.7% a laparoscopic approach. Pathologic stage included T1a (90.0%), T1b (1.1%), and T2b (8.9%). Fuhrman grades 1-3 were present in 18.9%, 77.8%, and 3.3% of patients, respectively. There were no cancer specific deaths. There was one local recurrence and no metastases. The overall survival at a median follow up of 26.5 months was 92.1% (95% confidence interval 83.1%-96.4%).

CONCLUSIONS

Clear cell papillary renal cell carcinoma typically presents at a low stage and grade and has favorable survival outcomes. A nephron-sparing approach to treatment should be considered when feasible due to the tumor's indolent nature and propensity towards multifocality.

Clear cell papillary renal cell carcinoma: an update after 15 years

Fifteen years since the first recognition of clear cell papillary renal cell carcinoma, this distinct renal tumour type is now well accepted as a distinct entity in major classification schemes. It occurs both with and without end-stage renal disease and may be multifocal or bilateral in both scenarios. Recognisable morphological features include clear cells lining branching glands and variable papillary formations with nuclear alignment. Most tumours are small (pT1a) and nucleolar grade 1-2. Immunohistochemistry consistently shows positivity for carbonic anhydrase IX and cytokeratin 7, and often high molecular weight cytokeratin or GATA3, the latter suggesting distal nephron phenotype. Labeling for AMACR and CD10 is consistently negative or minimal. Despite a resemblance to clear cell renal cell carcinoma, molecular alterations of VHL and chromosome 3p are typically lacking, with debatable rare exceptions. Potential mimics include clear cell renal cell carcinoma (with branching architecture or nuclear alignment), papillary renal cell carcinoma with clear cytoplasm, or rarely MITF family translocation renal cell carcinoma. Clinical behaviour is highly favourable with rare, debatable reports of aggressive behaviour. Combined with striking similarity to several extrarenal benign neoplasms, it would be reasonable to reclassify this entity as a benign or low malignant potential neoplasm. Using the nomenclature of the extrarenal counterparts, clear cell papillary (cyst)adenoma is proposed.

Computed tomography imaging characteristics of clear cell papillary renal cell carcinoma

Purpose:

Clear cell papillary (CCP) renal cell carcinoma (RCC) is a new subtype of RCC that was formally recognized by the International Society of Urological Pathology Vancouver Classification of Renal Neoplasia in 2013. Subsequently, CCP RCC was added to the 2016 World Health Organization Classification of Tumors of the Urinary System and Male Genital Organs. In this study, we retrospectively investigated the computed tomography (CT) findings of pathologically diagnosed CCP RCC.

Materials and Methods:

This study included 12 patients pathologically diagnosed with CCP RCC at our institution between 2015 and 2017. We reviewed the patient's CT data and analyzed the characteristics.

Results:

Nine solid masses and 3 cystic masses with a mean tumor size of 22.7±9.2mm were included. Solid masses exhibited slight hyper-density on unenhanced CT with a mean value of 34±6 Hounsfield units (HU), good enhancement in the corticomedullary phase with a mean of 195±34HU, and washout in the nephrogenic phase with a mean of 133±29HU. The walls of cystic masses enhanced gradually during the corticomedullary and nephrogenic phases. Solid and cystic masses were preoperatively diagnosed as clear cell RCC and cystic RCC, respectively.

Conclusions:

The CT imaging characteristics of CCP RCCs could be categorized into either the solid or cystic type. These masses were diagnosed radiologically as clear cell RCC and cystic RCC, respectively.

Clear Cell Papillary Renal Cell Carcinoma: A Recent Entity With Distinct Imaging Patterns

OBJECTIVE. Clear cell papillary renal cell carcinoma (RCC), an entity with strikingly indolent behavior, recently was added to the World Health Organization classification of renal tumors and represents the fourth most common histologic type of renal cell carcinoma. This article aims to describe the imaging features of clear cell papillary RCC along with its clinical and pathologic characteristics. MATERIALS AND METHODS. This retrospective study consisted of 27 patients with 44 clear cell papillary RCC tumors. The inclusion criteria were a pathologically proven clear cell papillary RCC and the availability of preoperative imaging including at least CT or MRI. Two experienced radiologists performed the imaging analysis independently. RESULTS. Patients (mean age, 62 years old) presented with renal failure in 26% of cases, and four had a tumor-predisposing disease. Multiple clear cell papillary RCC tumors occurred in 5 of the 27 patients. Two imaging patterns were recognizable. Solid clear cell papillary RCC (n = 23, 52%) presented as heterogeneous tumors with minor cystic changes (74%) and rarely exhibited calcifications (10%). All solid tumors showed hyperintensity on T2-weighted images compared with renal cortex and maximal enhancement on corticomedullary phase with a delayed washout. Cystic clear cell papillary RCC (n = 21, 48%) were classified as Bosniak IV (57%), III (33%), or IIF (10%), with a predominant unilocular pattern (76%). Pathologic stage according to TNM classification was mostly pT1a and low grade on nucleolar grade. All patients were alive at the date of last follow-up after treatment with no metastasis or recurrence. CONCLUSION. Clear cell papillary RCC exhibits two imaging patterns including cystic and solid in almost equal proportion. Imaging characteristics of solid clear cell papillary RCC including high signal T2 intensity and early arterial enhancement are unexpectedly distinct from papillary RCC and very similar to clear cell RCC.

Current Concepts of Non-Coding RNAs in the Pathogenesis of Non-Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a relatively rare malignancy of the urinary tract system. RCC is a heterogenous disease in terms of underlying histology and its associated underlying pathobiology, prognosis and treatment schedule. The most prevalent histological RCC subtype is clear-cell renal cell carcinoma (ccRCC), accounting for about 70-80% of all RCCs. Though the pathobiology and treatment schedule for ccRCC are well-established, non-ccRCC subtypes account for 20%-30% of RCC altogether, and their underlying molecular biology and treatment options are poorly defined. The class of non-coding RNAs-molecules that are generally not translated into proteins-are new cancer drivers and suppressors in all types of cancer. Of these, small non-coding microRNAs (miRNAs) contribute to carcinogenesis by regulating posttranscriptional gene silencing. Additionally, a growing body of evidence supports the role of long non-coding RNAs (lncRNAs) in cancer development and progression. Most studies on non-coding RNAs in RCC focus on clear-cell histology, and there is a relatively limited number of studies on non-ccRCC subtypes. The aim of this review is to give an overview of the current knowledge regarding the role of non-coding RNAs (including short and long non-coding RNAs) in non-ccRCC and to highlight possible implications as diagnostic, prognostic and predictive biomarkers.

A comparison of the prognosis of papillary and clear cell renal cell carcinoma: Evidence from a meta-analysis

OBJECTIVE

To compare the prognosis of papillary and clear cell renal cell carcinoma (RCC) in order to determine the optimal follow-up and therapy for patients with RCC.

METHODS

A systematic search of Web of Science, EMBASE, Cochrane Library, and PubMed databases was conducted for articles published through July 30, 2018, reporting on a comparison of the prognosis of papillary RCC and clear cell RCC using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

RESULTS

Of 1896 studies, 11 were considered for the evidence synthesis. A total of 35,832 patients were included. Of these patients, 6907 patients were diagnosed with papillary renal cell carcinoma, and 28,925 patients were diagnosed with clear cell renal cell carcinoma. The prognosis of papillary RCC was better than that of clear cell RCC (hazard ratio (HR) = 0.50; 95% confidence interval (CI) 0.45 to 0.56; P < .001; I = 91.9%). A subgroup analysis indicated that papillary RCC was associated with better outcomes (HR = 0.76, 95% CI 0.50-1.16), and a trend toward a higher risk of mortality was observed in patients with metastatic RCC presenting with papillary histology, but the difference was not statistically significant (HR = 1.12, 95% CI 0.71-1.76, P = .085). Pooled data suggested a lack of a significant difference between papillary RCC (p-RCC) type 1 and clear cell RCC (cc-RCC) (HR = 0.30, 95% CI 0.12-0.73, P = .085). The pooled HR for the prognosis of p-RCC type 2 compared to cc-RCC was 1.69 (95% CI 0.93-3.08; P = .032).

CONCLUSION

Papillary RCC is associated with better outcomes than clear cell RCC in patients without metastases, but not in patients with metastases. Optimal follow-up or therapy for patients with RCC should be assigned according to the tumor stage and subtype.

Current Challenges in Diagnosis and Assessment of the Response of Locally Advanced and Metastatic Renal Cell Carcinoma

Locally advanced and metastatic renal cell carcinoma (RCC) present a specific set of challenges to the radiologist. The detection of metastatic disease is confounded by the ability of RCC to metastasize to virtually any part of the human body long after surgical resection of the primary tumor. This includes sites not commonly included in routine surveillance, which come to light after the patient becomes symptomatic. In the assessment of treatment response, the phenomenon of tumor heterogeneity, where clone selection through systemic therapy drives the growth of potentially more aggressive phenotypes, can result in oligoprogression despite overall disease control. Finally, advances in therapy have resulted in the development of immuno-oncologic agents that may result in changes that are not adequately evaluated with conventional size-based response criteria and may even be misinterpreted as progression. This article reviews the common challenges a radiologist may encounter in the evaluation of patients with locally advanced and metastatic RCC. ^©RSNA, 2019.

Clear Cell Papillary Renal Cell Carcinoma

Clear cell papillary renal cell carcinoma (ccpRCC) is a recently recognized entity and represents the fourth most common variant of renal cell carcinoma (RCC). It has unique morphologic and immunohistochemical features and demonstrates an indolent clinical behavior. Microscopically, it may mimic other RCCs with clear cell features, such as clear cell RCC, translocation RCC, and papillary RCC with clear cell changes. A high index of suspicion is required to keep ccpRCC in the differential diagnosis of RCCs with features of clear cell and/or papillary architecture. In equivocal cases, immunohistochemistry is generally sufficient to substantiate the diagnosis of ccpRCC. In this review, we discuss the clinical, gross, and histopathologic features, immunohistochemical and genetic profiling, and prognosis of ccpRCC.

CT and MR imaging for solid renal mass characterization

As our understanding has expanded that relatively large fraction of incidentally discovered renal masses, especially in small size, are benign or indolent even if malignant, there is growing acceptance of more conservative management including active surveillance for small renal masses. As for advanced renal cell carcinomas (RCCs), nonsurgical and subtype specific treatment options such as immunotherapy and targeted therapy is developing. On these backgrounds, renal mass characterization including differentiation of benign from malignant tumors, RCC subtyping and prediction of RCC aggressiveness is receiving much attention and a variety of imaging techniques and analytic methods are being investigated. In addition to conventional imaging techniques, integration of texture analysis, functional imaging (i.e. diffusion weighted and perfusion imaging) and multivariate diagnostic methods including machine learning have provided promising results for these purposes in research fields, although standardization and external, multi-institutional validations are needed.

Pathologic and clinical characteristics of early onset renal cell carcinoma

The majority of renal cell carcinomas (RCCs) occur within the 7th decade of life, uncommonly arising in adults ≤46 years. We reviewed the clinicopathologic features of early onset RCC and evaluated the role of immunohistochemistry (IHC) in potentially identifying diagnoses of newly recognized RCC subtypes that may have been previously misclassified. A retrospective review was performed from 2011-2016 for cases of RCC. Early onset RCC was defined as ≤46 years of age. Clinicopathologic findings and hematoxylin and eosin (H&E) slides were reviewed on early onset RCC patients. IHC was performed on all cases previously diagnosed as unclassified or papillary. Clinicopathologic findings were compared to a control group of RCC patients >46 years over the same time period. We identified 98/598 (16.4%) early onset RCCs. The median age in the early onset RCC and control group was 38.4 and 62.8 years, respectively. The early onset RCC group contained 33/96 (34.3%) females and 63/96 (65.6%) males, including 52/96 (54.2%) whites, 39/96 (40.6%) African Americans, 4/96 (4.2%) Hispanics, and 1/96 (1%) Asian. Nonwhites were significantly more likely to develop early onset RCC (P=.004). Early onset RCCs included 52% clear cell, 28.6% papillary, 8.2% unclassified, 5.1% chromophobe, 3.1% clear cell papillary(CCP), and 3 other rare tumors. Six unclassified and 26 papillary RCCs had tissue available for IHC. Two of 6 (33.3%) unclassified RCCs were reclassified (1 CCP, 1 Xp11 translocation). One of 26 (3.8%) papillary RCCs was reclassified as CCP. Early onset RCCs were more likely to occur in nonwhites (P=.004), be lower stage (P=.03), and undergo partial nephrectomy (P=.002). Few unclassified and papillary tumors were reclassified with IHC.

The Concentration of Vanadium in Pathologically Altered Human Kidneys

Vanadium has a unique and beneficial effect on both humans and animal organisms; however, excessive amount of the above-mentioned metal can cause many alterations in tissues and organs, including the kidneys. The aim of the study was to determine the concentration of vanadium (V) in the kidneys removed from patients due to lesions of various etiologies, including the rejection of the transplanted kidneys. Additionally, we determined the influence of selected biological and environmental factors on the V concentration. The study material consisted of the kidneys with tumor lesions (n = 27) and extracted kidney grafts (n = 10) obtained from patients from the north-western Poland. The V concentrations were assessed by atomic absorption spectrophotometry emission in inductively coupled argon plasma and expressed in concentrations in dry weight (dw). Statistically significant differences were observed for V concentrations in the renal medulla between the kidneys with tumors and renal grafts, where the lowest concentration of V was observed. The kidneys in more advanced stages of the tumor (T3 + T4) contained more vanadium than the kidneys of T1 + T2 stages and medians were 2.07 and 1.51, respectively. We also compared the V concentration in the kidneys between the renal grafts (K2) and the kidneys with tumor (K1) in two stages of advancement: T1 with T2 (K1_1 + 2) and T3 with T4 (K1_3 + 4). Statistically significant differences were noted between the renal medullae of the above-mentioned groups of kidneys.According to the previous studies on the concentrations of other heavy metals, renal grafts accumulate less vanadium than cancerous kidneys, what can be associated with the immunosuppressive drugs taken by patients after the transplantation.