Adult Renal Cell Carcinoma Research Articles

Pediatric renal cell carcinoma

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

Adult Xp11 Translocation Renal Cell Carcinoma Diagnosed by Cytogenetics and Immunohistochemistry

To determine the incidence of Xp11 translocation renal cell carcinoma (RCC) in adult patients using cytogenetics and immunohistochemstry. Cytogenetic studies were prospectively done using tumor samples from 443 consecutive adult Japanese patients (ages 15-89 years) who underwent nephrectomy for RCC. TFE3 immunohistochemistry was done for cases in which cytogenetic results were not obtained. Clinicopathologic characteristics of Xp11 translocation RCC were examined. Mitotic cells suitable for cytogenetic analysis were obtained in 244 tumor samples (55%); among these, we identified 4 cases (1.6%) of Xp11 translocation RCC. TFE3 immunohistochemistry identified 3 positive cases (1.5%) among the remaining 199 cases. The median age of the 7 patients was 41 years (range, 15-59 years), and 15% of RCC patients (4 of 26) who were younger than ages 45 years had this type of RCC. Of the four Xp11 translocation RCC patients whose karyotypes were determined, two had an ASPL-TFE3 gene fusion. Of these 2, 1 had pulmonary metastasis at presentation, and the other developed liver metastasis 12 months after nephrectomy and died of the disease. The remaining two patients had PRCC-TFE3 and PSF-TFE3 gene fusions, respectively. Both had nodal involvement but remained disease free for 3 and 5 years, respectively, after surgical resection of lymph node metastases. Of the 3 immunohistochemically diagnosed patients, 1 had nodal metastases at presentation and died 9 months after surgery. This is the first report to determine the incidence of Xp11 translocation RCC in adult patients. We found that this disease is relatively common in young adults.

Solitary multilocular cystic renal cell carcinoma in adults: Diagnostic problems, pathological features and treatment

Multilocular cystic renal cell carcinoma represents a rare clinical entity in adults. This report describes the authors' experience with seven tumours, including the first two tumours in the literature diagnosed during pregnancy.

Renal cell carcinoma in the pediatric population: Results from the California Cancer Registry

Renal cell carcinoma (RCC) is a rare disease in children and adolescents. This study aimed to review epidemiologic characteristics and survival for pediatric RCC patients using a large, population-based database. The California Cancer Registry (CCR) was reviewed from 1988 to 2004. All cases of RCC in patients younger than 21 years were identified and annual age-adjusted incidence rates were determined for the overall population and subdivided by ethnicity. Tumors were classified by stage and grade, and actuarial mortality rates were calculated. From 1988 to 2004, 43 cases of RCC were identified in patients younger than 21 years, accounting for 4.3% of all renal tumors in this age group. The overall annual age-adjusted incidence was 0.01/100,000 with the tumor more common in non-Hispanic blacks (0.03/100,000) compared to non-Hispanic whites (0.01/100,000), Hispanics (<0.01/100,000), and non-Hispanic Asians/Pacific Islanders (<0.01/100,000). The mean age at presentation was 15.4 years (SD 4.03, SE 0.615). RCC was identified more frequently in females (58.14%). At the time of presentation, 53.49% of tumors were localized, 20.93% were regionally advanced, and 25.58% were metastatic. The observed actuarial survival at 5 and 10 years was 61% (+/-15.7%). Pediatric RCC is an uncommon and aggressive tumor that occurs most frequently in children in the second decade of life, more often in females and blacks. The epidemiological characteristics of this tumor differ from adult RCC and Wilms tumor, suggesting its distinctive biology and potential need for alternative treatment strategies.

Treatment of adult rhabdoid renal cell carcinoma with sorafenib

Renal cell carcinoma (RCC) with rhabdoid features is an uncommon and highly aggressive malignancy. We report a case of adult clear-cell RCC with extensive rhabdoid features treated with the tyrosine kinase inhibitor sorafenib. A review of the literature summarizes important aspects of this malignancy. We discuss clinical and histological findings as well as the patient's response to sorafenib therapy.

Young Age Is Independent Prognostic Factor for Cancer-Specific Survival of Low-Stage Clear Cell Renal Cell Carcinoma

To clarify the clinicopathologic features and prognosis of renal cell carcinoma (RCC) in young adults. The features of RCC in young adults have been reported, but the results have been conflicting. The data from 619 patients with RCC were analyzed. The patients were divided into 2 groups according to age at diagnosis, </=55 or >55 years of age. The clinicopathologic parameters were compared, and a survival analysis was performed. Younger patients were more likely to have a lower disease stage (P < .001), lower nuclear grade (P = .018), and smaller tumor size (P = .005) and a greater 5-year cancer-specific survival rate (P < .001) than older patients. Young age was a favorable prognostic factor for cancer-specific survival of clear cell RCC (P < .001). On multivariate analysis, young age was independently associated with a longer cancer-specific survival rate of clear cell RCC (P = .003). In addition, the prognostic implication of age differed between low (I or II) and high (III or IV) stage tumors. In low-stage clear cell RCC, young age was significantly associated with prolonged cancer-specific survival on univariate (P < .001) and multivariate (P = .007) analyses, but not in high-stage clear cell RCC (P = .906). RCC in patients <55 years presented with a lower stage, lower nuclear grade, and smaller size than did the older patients. Young age was an independent prognostic factor for cancer-specific survival of low-stage clear cell RCC.

Renal Cell Carcinoma in Young and Old Patients—Is There a Difference?

Renal cell carcinoma is rare in patients younger than 40 years and conflicting data regarding presentation and outcome are present in the literature. We reviewed our experience with young patients with renal cell carcinoma and compared them to their older counterparts. We identified 1,720 patients 18 to 79 years old who were treated with partial or radical nephrectomy for renal cell carcinoma between 1989 and 2005. Patients were grouped according to age and outcome analysis was performed. Of the 1,720 patients with renal cell carcinoma 89 (5%), 672 (39%) and 959 (56%) were younger than 40, 40 to 59 and 60 to 79 years old, respectively. There were no significant differences in sex, tumor size, TNM stage or multifocality by age group. However, patients younger than 40 years were significantly more likely to present with symptomatic tumors (p = 0.028). Additionally, there were significant differences in histology by age (p <0.001), that is chromophobe histology decreased while papillary histology increased with age. Despite similar tumor sizes in each age group the percent of patients treated with partial nephrectomy decreased with age. Of patients younger than 40 years 49% were treated with partial nephrectomy compared with 35% and 30% of those 40 to 59 and 60 to 79 years old, respectively (p <0.001). At a median followup of 2.6 years (range 0 to 14.5) we did not observe a significant difference in cancer specific survival according to age (p = 0.17). Younger patients with renal cell carcinoma are more likely to have symptomatic tumors with chromophobe histology, although the prognosis appears similar across age groups. Older patients are more likely to be treated with radical nephrectomy, which requires careful scrutiny for current clinical practice.

Local lymph node involvement in pediatric renal cell carcinoma: A report from the Italian TREP project

One of the most important adverse prognostic factors for adult renal cell carcinoma (RCC) is the retroperitoneal lymph node involvement. The aim of this article is to study the prognostic significance of local lymph node involvement in pediatric RCC and the role of retroperitoneal lymph node dissection (RLND) at diagnosis. The series included 16 patients with RCC and lymph nodes involvement registered in the Italian Rare Tumors Pediatric Age (TREP) project, accounting for 26.2% of 61 pediatric RCC observed at AIEOP centers. A radical nephrectomy was performed in all cases: at diagnosis in 12 cases, after preoperative chemotherapy (CT) in 4 cases. As a part of the same procedure 9 patients underwent RLND, and 7 received a more limited lymph nodes resection. Five (31.2%) developed disease recurrence 2-34 months after diagnosis (median, 6 months) plus 1 developed progression; 6 patients died, 1 of them from secondary leukemia. Among the nine patients receiving RLND, eight are alive and disease free. This compares with only one patient surviving among the seven receiving a more limited lymph nodes resection. The estimated 25-year PFS and OS rates for all patients were 61.4% (95% CI 33.2-80.5) and 50.8% (95% CI 16.5-77.5), respectively. Lymph node involvement is an unfavorable prognostic factor in children with RCC. RLND appears to be a critical factor to improve the outcome. However, when compared to similar adult patients, the outcome in children appears to be better, suggesting that pediatric RCC, or the host, may be critical differences.

Translocation renal cell carcinoma

Pediatric renal cell carcinoma (RCC) is clinically distinct from adult RCC. Characterization of the unique biological and clinical features of pediatric RCC are required. A retrospective review and biological analysis of all RCC cases presenting to Cincinnati Children's Hospital Medical Center (CCHMC) in the last 30 years was undertaken. Cases were classified according to the recent World Heath Organization morphologic classification and according to TFE3/TFEB status. A literature review of pediatric TFE+ cases was performed. Eleven cases of RCC with clinical data were identified in our institutional review as follows: 6 clear cell, 2 papillary, 2 translocation, and 1 sarcomatoid. Upon reanalysis, 1 papillary and 1 sarcomatoid were confirmed, 1 case was "unclassified", and 8 of 11 (72.7%) had features consistent with translocation morphology. Of these 8, all demonstrated immunoreactivity for TFE3 (7 patients) or TFEB (1 patient) protein. In 3 cases, cytogenetics was available, each demonstrating confirmatory MiTF/TFE translocations. Seven of 8 TFE+ RCC patients presented with TNM Stage III/IV disease. Literature analysis confirmed a significant increase in advanced stage presentation in pediatric TFE+ RCC compared with TFE- RCC. Fourteen of fifteen (93.3%) patients with TFE+ stage III/IV RCC due to lymph node spread (N+ M(0)) remain disease free with a median and mean follow-up of 4.4 and 6.3 years, respectively (range, 0.3-15.5). Translocation morphology RCC is the predominant form of pediatric RCC, associated with an advanced stage at presentation. Patients with TFE+ N+ M(0) RCC maintain a favorable short-term prognosis after surgery alone. Young RCC patients should be screened for translocation morphology, and the screening information should be considered when debating adjuvant therapy.

POS-02.87: Is the correct diagnosis being assigned to adult chromophobe renal cell carcinoma: An immunocytochemical verification?

POS-02.87: Is the correct diagnosis being assigned to adult chromophobe renal cell carcinoma: An immunocytochemical verification?

Xp11 Translocation Renal Cell Carcinoma in Adults: Expanded Clinical, Pathologic, and Genetic Spectrum

The recently recognized Xp11 translocation renal cell carcinomas (RCCs), all of which bear gene fusions involving the TFE3 transcription factor gene, comprise at least one-third of pediatric RCC. Only rare adult cases have been reported, without detailed pathologic analysis. We identified and analyzed 28 Xp11 translocation RCC in patients over the age of 20 years. All cases were confirmed by TFE3 immunohistochemistry, a sensitive and specific marker of neoplasms with TFE3 gene fusions, which can be applied to archival material. Three cases were also confirmed genetically. Patients ranged from ages 22 to 78 years, with a strong female predominance (F:M=22:6). These cancers tended to present at advanced stage; 14 of 28 presented at stage 4, whereas lymph nodes were involved by metastatic carcinoma in 11 of 13 cases in which they were resected. Previously not described and distinctive clinical presentations included dense tumor calcifications such that the tumor mimicked renal lithiasis, and obstruction of the renal pelvis promoting extensive obscuring xanthogranulomatous pyelonephritis. Previously unreported morphologic variants included tumor giant cells, fascicles of spindle cells, and a biphasic appearance that simulated the RCC characterized by a t(6;11)(p21;q12) chromosome translocation. One case harbored a novel variant translocation, t(X;3)(p11;q23). Five of 6 patients with 1 or more years of follow-up developed hematogenous metastases, with 2 dying within 1 year of diagnosis. Xp11 translocation RCC can occur in adults, and may be aggressive cancers that require morphologic distinction from clear cell and papillary RCC. Although they may be uncommon on a percentage basis, given the vast predominance of RCC in adults compared with children, adult Xp11 translocation RCC may well outnumber their pediatric counterparts.

Symptom burden among patients with Renal Cell Carcinoma (RCC): content for a symptom index

BackgroundRenal cell carcinoma (RCC) has multiple symptoms stemming from disease and treatments. There are few validated scales for evaluating RCC symptoms.MethodsA national cross-sectional study of adult RCC patients was conducted from October to December 2003 to define patient-reported RCC symptomology. Participants were asked open-ended questions regarding their signs and symptoms and completed an 86-item pilot questionnaire of physical and psychological symptoms. Patients were asked to rate the relevancy and clarity of each pilot question using a 5-point Likert scale. Subsequent open-ended caregiver interviews and a provider panel relevance ranking contributed additional information.ResultsThe average age of the participants (n = 31) was 55 years; 55% of patients were male, 74% had attended college, and 97% were Caucasian. The five most frequent symptoms among localized-stage patients (n = 14) were irritability (79%), pain (71%), fatigue (71%), worry (71%), and sleep disturbance (64%). Among metastatic patients (n = 17), the five most frequent symptoms were fatigue (82%), weakness (65%), worry (65%), shortness of breath (53%), and irritability (53%). More than 50% of localized and metastatic-stage patients reported pain, weakness, fatigue, sleep disturbance, urinary frequency, worry, and mood disorders as being moderately to highly relevant.ConclusionA brief, self-administered RCC Symptom Index was created that captures the relevant signs and symptoms of both localized and metastatic patients. Pending additional content validation, the Index can be used to assess the signs and symptoms of RCC and the clinical benefit resulting from RCC treatment.

Renal cell carcinoma arising in a long pre-existing angiomyolipoma

Angiomyolipoma (AML) is a mixed mesenchymal tumor belonging to the family of perivascular epithelioid cell tumors. Concurrent development of AML and adult renal cell carcinoma (RCC) is very rare. Herein is presented a unique case in which RCC arose within a previously detected AML tumor mass. A 40-year-old woman had been diagnosed with AML of the right kidney. Fifteen years later, during a regular radiographic examination, a new lesion was detected at the lower pole of the right kidney adjacent to the previously described AML. Because RCC was clinically suspected, the patient underwent right nephrectomy. Macroscopically, the tumor had a yellowish, transparent, fatty area and an opaque yellowish area with cystic features. Microscopically, the former tumor, consisting of an admixture of mature adipose tissue with smooth muscle and vascular tissue, was diagnosed as AML. The latter tumor was diagnosed as RCC (clear cell type). RCC was not completely enclosed within the AML, but overlapped it. No fibrous capsule was found between these tumors. Although this situation is very rare, from a clinical and pathological point of view it is important to consider the possibility that RCC might arise within AML. The relationship between the two lesions is discussed with a review of the literature.

Renal Cell Carcinoma With Rhabdoid Features: An Aggressive Neoplasm With Overexpression of p53

Adult renal cell carcinoma (RCC) with rhabdoid features is a recently recognized morphologic variant of kidney carcinoma. To date, only very few studies have been published on this subject and p53 was not previously studied. To evaluate clinical attributes, morphology, and immunohistochemistry in RCC with rhabdoid component. Reviewing a consecutive series of 310 RCCs, we identified 14 cases of RCC with rhabdoid features. All cases were reviewed and subjected to detailed clinical and pathologic studies with immunohistochemical evaluation of p53. All tumors were clear RCCs with rhabdoid component representing from 5% to 50% of the tumor volume. Rhabdoid cells were large with a central eosinophilic intracytoplasmic inclusion and an eccentric atypical nucleus. Tumor necrosis was common (13/14) and sometimes extensive. Nine of 14 tumors were staged pT3, 4 of 14 were pT2, and only 1 tumor was pT1. On immunohistochemistry, rhabdoid cells were positive for vimentin (14/ 14), epithelial membrane antigen (11/14), and cytokeratin (9/14). Desmin and smooth muscle actin were always negative. p53 was positive in 10 of 14 tumors in the rhabdoid areas (5%-50% of tumor cells stained) but only in 5 of 14 cases in usual clear renal cell areas. In the follow-up, 10 of 14 patients developed metastases and 6 of 14 died of the disease. The median of survival was 8 months. We showed that RCC with rhabdoid features is a very aggressive neoplasm with a poor prognosis. We observed an overexpression of p53 in the rhabdoid component that may be implicated in the tumor dedifferentiation.

Renal Cell Carcinoma in Adults 40 Years Old or Less: Young Age is an Independent Prognostic Factor for Cancer-Specific Survival

ObjectivesRenal cell carcinoma (RCC) is uncommon in young adults. Based on the few studies published to date, it is difficult to determine whether this tumour has a particular progression pattern. This retrospective, multicentre study analysed RCC in young patients, defined as ≤40 yr old, compared to RCC in older patients. MethodsBetween 1988 and 2000, 1233 patients, 93 under 40 yr old and 1140 older (mean ages, 34.2 and 61.9 years, respectively) underwent surgery for RCC in four teaching hospitals. Clinical and biologic parameters at diagnosis were compared and subjected to univariate and multivariate analyses to study survival. Mean follow-up was 4.5 yr for young and 4.1 yr for older patients. ResultsWhen comparing younger to older patients, respectively, they had a lower male-to-female ratio (1.2 vs. 2.5), lower stage (84.9% vs. 67.4% pT1–pT2N0M0; p=0.001), and fewer clear-cell carcinomas (73.1% vs. 82%), but more papillary carcinomas (20.4% vs. 11.4%; p=0.01) and better 5-yr cancer-specific survival rates (90.8% vs. 78.3%; p=0.005). Independent prognostic factors for survival, in the order of decreasing impact, were tumor stage (p<0.0001), Fuhrman nuclear grade (p<0.0001), and age ≤40 yr at diagnosis (risk ratio 0.4, p<0.047). Young patients tended to have a better 5-yr progression-free survival (80.5% vs. 70.7%; p=0.05). ConclusionsRCC in young adults was more often localised at diagnosis and had a better prognosis than the disease in older subjects. Age under 40 yr old was an independent prognostic factor for survival.

Renal cell carcinoma: Children’s hospital Boston experience

ObjectivesTo review our experience to better define pediatric renal cell carcinoma (RCC). Pediatric RCC is rare, and recent data suggest it may be a unique disease. MethodsA retrospective review was conducted of hospital and pathology records from 1965 to 2003. Patients with RCC were identified, and the clinical and pathologic data were extracted. ResultsSince 1965, 11 patients with RCC were treated, accounting for 3% of all renal tumors. In the first 20 years, 191 patients with renal tumor were treated, of whom 3 had RCC. In the most recent 15 years, 172 patients with renal tumor were treated, of whom 8 had RCC. The mean age at presentation was 14.7 years (range 9 to 17 years), with a female predominance (2.7:1). The clinical signs and symptoms included hematuria in 36%, flank pain in 27%, and an abdominal mass in 9%; 36% were discovered incidentally. Of the 11 RCC tumors, 45% were papillary and 55% were clear cell carcinoma. Papillary tumors presented at a worse stage and displayed more aggressive clinical behavior. Of 10 patients with available follow-up data, 6 had no evidence of RCC, 1 had died of other causes, 2 had died of metastatic RCC, and 1 was alive with recurrent RCC at a mean follow-up of 4.9 years. ConclusionsThe clinical presentation, pathologic characteristics, and clinical behavior of pediatric RCC are different than those for adult RCC. A possible increasing incidence of RCC in children would parallel an increased incidence in adults. Our findings warrant additional and coordinated efforts to better characterize RCC in children.

Characterization of quantitative chromosomal abnormalities in renal cell carcinomas by interphase four-color fluorescence in situ hybridization

Renal cell carcinomas (RCC) in adults are histologically heterogeneous solid tumors with specific chromosomal abnormality patterns included in the World Health Organization (WHO) classification. To overcome some of the drawbacks of cytogenetic and comparative genomic hybridization (CGH) analyses, we designed a first-generation cytogenetic diagnostic test using four-color fluorescence in situ hybridization (FISH) on interphase nuclei. We selected 51 bacterial artificial chromosome and P1-derived artificial chromosome clones covering 17 chromosomal regions involved in the abnormalities of the adult RCC histologic subtypes. An initial set of probes allowed the identification of clear-cell RCC, papillary RCC, and other RCC on a single slide. A second test allowed the detection of additional chromosomal abnormalities or aberrations specific to chromophobic RCC and oncocytomas. We tested 25 cases of RCC, and the results were in agreement with those of cytogenetic techniques and/or CGH methods. The techniques appeared to be very sensitive, because small tumoral cell clones that were undetected by other cytogenetic methods were identified with this method. It was concluded that the multicolor FISH test was specific and sensitive, easy to perform, and could be part of the investigation process in RCC.

Local lymph node involvement does not predict poor outcome in pediatric renal cell carcinoma.

Local lymph node involvement in adults with renal cell carcinoma (RCC) is associated with poor outcome. The prognostic significance of local lymph node involvement in children with RCC has not been studied systematically. A retrospective review of patients treated at St Jude Children's Research Hospital (Memphis, TN) and an extensive review of the medical literature were undertaken to evaluate the prognostic significance of local lymph node involvement in pediatric RCC. Thirteen patients with the diagnosis of RCC were treated at St. Jude since the hospital's inception in 1962. Four patients presented with lymph node-positive, distant metastasis-negative (N + M0) disease, and all 4 remain disease free after resection without adjuvant therapy (follow-up duration, 2-9 years). A systematic review of the literature including 243 pediatric patients with RCC revealed stage-specific survival rates of 92.5%, 84.6%, 72.7%, and 12.7% for Stage I-IV disease, respectively. Of 58 children with N + M0 RCC for whom outcome data were available, 42 (72.4%) were alive without disease at last follow-up. Among patients whose therapy could be discerned, those who received no adjuvant therapy fared as well (15 of 16 alive) as those who received various adjuvant treatments (22 of 31 alive). Children with lymph node-positive RCC in the absence of distant metastatic disease had a relatively favorable long-term prognosis, with survival rate nearly triple those of adult historical controls. Until highly effective therapies for RCC are identified, these children should not be exposed to adjuvant treatment. Further investigation of the biologic differences between adult and pediatric RCC is warranted.

Multigene methylation analysis of Wilms' tumour and adult renal cell carcinoma.

To investigate the role of epigenetic gene silencing in the pathogenesis of Wilms' tumour and renal cell carcinoma (RCC), we determined their methylation profile using a candidate gene approach. Thus, 40 Wilms' tumours and up to 49 adult RCC were analysed by methylation-specific PCR for promoter methylation at CASP8, CDH1, CDH13, DAPK, MGMT, NORE1A, p14ARF and RARB2 in primary Wilms' tumours and CASP8, CDH1, CDH13, CRBP1, DAPK, MGMT, MT1G, NORE1A, p16INK4a, SDHB and RARB2 in primary RCC. Both tumour sample sets had previously been analysed for RASSF1A promoter methylation, and p16INK4a methylation results were also available for the Wilms' tumour samples. Wilms' tumours demonstrated a high incidence of methylation at CASP8 (43%) and MGMT (30%), intermediate frequencies at NORE1A (15%), p14ARF (15%), p16INK4a (10%), DAPK (11%) and CRBP1 (9%), but promoter methylation was rare or absent at RARB2 (0%), CDH13 (0%) and CDH1 (3%). No association was detected between methylation of RASSF1A, CASP8 or MGMT in individual tumours. The frequency of MGMT methylation was higher in stage 1 and 2 tumours (50%) than in stage 3 and 4 tumours (17%) but this did not reach statistical significance (P=0.06). RCC were most frequently methylated at DAPK (24%), MT1G (20%), NORE1A (19%), CDH1 (16%) and MGMT (9%) and not or rarely at SDHB (4%), RARB2 (0%), p16INK4a (0%) and CDH13 (3%). There were no associations between methylation of RASSF1A, DAPK and CDH1 in individual tumours. Papillary RCC demonstrated a higher frequency of DAPK methylation (43%) than clear cell tumours (19%) (P=0.14). We have demonstrated that de novo promoter methylation is frequent in Wilms' tumour and RCC, and these data enable methylation profiles to be constructed for each tumour type. Thus, combining our results with data published previously, it appears that promoter methylation occurs frequently (> or =20% of primary tumours) at CASP8, SLIT2 and RASSF1A in Wilms' tumour and at RASSF1A, TIMP3, DAPK, SLIT2, MT1G and GSTP1 in RCC.

Adult Rhabdoid Renal Cell Carcinoma Divergent Differentiation of Conventional (Clear Cell) Carcinoma

c Background.—Pediatric rhabdoid tumor of the kidney is regarded as a distinct neoplasm, whereas rhabdoid differentiation in adult renal cell carcinoma is usually found in association with conventional (clear cell) tumor, from which it is thought to evolve. Objective.—To further characterize the rhabdoid phenotype in adult renal cell carcinoma and to determine its origin by genetic analysis. Design.—We performed histologic, immunophenotypic, and genetic analyses on 5 cases of adult renal cell carcinoma with rhabdoid differentiation, 3 samples of adjacent conventional (clear cell) tumor, and 6 conventional (clear cell) control tumors. Results.—Rhabdoid tumors differed from conventional (clear cell) carcinoma as follows: (1) macroscopically, rhabdoid tumors were solid white uniform masses; (2) microscopically, they had large rhabdoid cells with abundant eosinophilic cytoplasm, reduced lipid content, and the absence of a branching vascular pattern; and (3) biologically, they had a high metastatic potential. Despite these differences, loss of chromosome 3p in both the rhabdoid and clear cell carcinoma samples from 1 patient suggested a clonal origin. An identical mutation of the VHL gene in both rhabdoid and clear cell tumor samples from 2 patients confirmed a clonal origin for the histologically distinct tumor types in those cases. Conclusion.—Adult rhabdoid renal cell carcinoma can in some cases arise from conventional (clear cell) renal carcinoma and should be considered a clinically important form of renal cell carcinoma separate from, but analogous to, sarcomatoid change. (Arch Pathol Lab Med. 2002;126:1506‐1510)