Renal oncocytoma: clinical and biological correlates

Renal Oncocytoma: An Algorithm for Diagnosis and Management

Renal oncocytoma is an uncommon tumor that exhibits numerous features which are characteristic but not necessarily unique. Percutaneous biopsy is a safe method of diagnosis. However, differentiation from other tumor subtypes often requires sophisticated analysis and is not universally feasible. This is why, surgical management can be considered as a first-line treatment or after surveillance. Potential triggers for change in management are: tumor size >3 cm, stage progression, kinetics of size progression (>5 mm/y), and clinical change in patient or tumor factors. Long-term follow-up data are lacking and greater centralization should be considered to reach adequate management.

Thyroid and renal tumors in patients treated with long-term lithium: case series from a lithium clinic, review of the literature and international pharmacovigilance reports

BACKGROUND

Cancer had never been considered as a relevant problem in patients treated with lithium until 2015, when a document published by the European Medicine Agency concluded that long-term use of lithium might induce renal tumors. A few months later, we observed the case of a woman treated with lithium for 18 years who was diagnosed with both thyroid and renal tumors.

METHODS

This study aimed to investigate the correlation between lithium treatment and thyroid or renal tumors. We analyzed clinical records in our lithium clinic database, causes of death of patients who had been visited at least once at the lithium clinic, reports of lithium adverse reactions in the European and WHO pharmacovigilance databases, and published cases of thyroid and renal tumors in long-term lithium-treated patients.

RESULTS

Of the 1871 lithium patients who had been visited at least once between 1980 and 2013, eight had been diagnosed with thyroid papillary carcinoma and two with clear-cell renal-cell carcinoma. No cases of thyroid cancer and only one case of renal tumor were the cause of death according to the 375 available death certificates. VigiAccess database contained a total of 29 and 14 cases of renal and thyroid tumors, respectively. EudraVigilance database contained 21 cases of renal and 8 of thyroid neoplasms. Literature search yielded 6 published cases of thyroid papillary carcinoma and 25 cases of various renal tumors. However, two population-based studies did not find any increased risks of cancer in patients exposed to lithium, whereas two nationwide studies did not find any excess of renal tumors.

CONCLUSION

So far it has not been possible epidemiologically to confirm an increased risk of thyroid or renal cancers associated with lithium. Such a conclusion is supported by the findings of low rates and mortalities of thyroid or renal cancers from the present lithium clinic data.

Immunohistochemistry of Complement Response on Human Renal Cell Carcinoma Biopsies

The goal of the study was to characterize the complement humoral and cellular antitumor responses on primary renal cell carcinoma biopsies. As an original observation, complement activation was found on 11/22 cases. Classical complement pathway activation was characterized by tumor C1q complement protein and IgG deposition (5/22 cases). Alternative or nonimmune complement pathway activation was seen as tissue deposition of C3 (6/22 cases). The membrane attack complex was present in cases with alternative complement pathway activation at the sites of tumor necrosis. Renal cell carcinomas with complement activation overexpressed at least one of the complement regulatory factors (membrane cofactor protein, decay accelerating factor, membrane attack complex inhibitor) and major histocompatibility complex class II molecules. Tumor infiltrating lymphocytes were present in most of the renal cell carcinomas with complement activation (8/11). However, the number of tumor-infiltrating lymphocytes was correlated with the intensity of major histocompatibility complex-ll expression in 18/22 cases. Detection of complement activation and immune cell infiltrates on renal cell carcinoma primary biopsies may serve as a new predictive factor for immunotherapy.

A Rare Benign Tumor in a 14-Year-Old Girl

Background

Oncocytomas are the second most common benign renal neoplasm but, unfortunately, they are difficult to differentiate from renal cell carcinoma. Renal oncocytomas are rare and have mostly been reported in adults. To our knowledge, this is only the sixth pediatric reported case of renal oncocytoma worldwide.

Case Presentation

A 14-year-old Yemeni girl with a recurrent history of urinary tract infections came to our clinic complaining of left flank pain with a frontal headache. Ultrasound showed a 3 cm, well-defined echogenic lesion with mild vascularity. This lesion increased in size on her subsequent follow-ups. Computed tomography showed no intralesional fat, vessels invasion, or enlarged lymph nodes. The patient underwent laparoscopic radical nephrectomy, and a pathology report confirmed the diagnosis of renal oncocytoma.

Conclusion and Recommendations

We present the rare occurrence of renal oncocytoma in a pediatric patient and highlight the importance of considering oncocytomas in the diagnosis of a renal mass.

Coexisting papillary and clear renal cell carcinoma in the same kidney

Renal cell carcinoma (RCC) is the most common solid lesion of the kidney. Bilateral synchronous benign and malignant renal tumors have been defined in some reports. However, unilateral concordance of malignant renal tumors is very rare and there are only a few cases that had synchronous different subtypes of malignant renal tumors arising within the same kidney. Herein, we describe a 67-year-old male patient who had clear cell RCC and papillary RCC in his right kidney that were successfully treated with radical nephrectomy. We also reviewed the pertinent literature.

Synchronous colonic adenocarcinoma and renal oncocytoma: a case report and literature review

We present the case of a patient with an adenocarcinoma of the colon associated with an oncocytoma of the kidney. A left colonic cancer was diagnosed at colonoscopy and an incidental finding of a left renal mass was noted, with a staging computerized tomography scan. Following a left hemicolectomy and a left nephrectomy, the pathological report confirmed the presence of a colonic adenocarcinoma and revealed that the left renal mass was an oncocytoma. This case report reviews the management decisions associated with incidental renal masses as well as the treatment of synchronous neoplasia.

Case report of a symptomatic giant renal oncocytoma

Renal oncocytomas are benign tumours, often asymptomatic, and picked incidentally on radiological imaging. We present a case report of a symptomatic giant renal oncocytoma in a 61-year old man having lower back/right flank pain. A large right renal mass was identified on abdominal CT scan. Radiological features were not sufficient to differentiate this lesion from renal cancer. Right radical nephrectomy was performed. Typical features of oncocytoma, without evidence of malignancy, were seen on histological examination of the specimen. In this report, we discuss literature review of radiological, genetic, and pathological characteristics of renal oncocytoma.

Renal oncocytoma revisited: a clinicopathological study of 109 cases with emphasis on problematic diagnostic features

AIM

To evaluate problematic diagnostic features in renal oncocytoma.

METHODS AND RESULTS

One hundred and nine cases of oncocytoma were reviewed and the problematic gross and microscopic features recorded. Multifocal and bilateral neoplasms were found in 12 (11%) and five (4.6%) cases, respectively. Haemorrhage was seen grossly in 30 (27.5%) neoplasms and a central scar was identified in 35 (32.1%). On microscopy, perinephric fat extension was present in 17 (15.6%) neoplasms and vascular extension was identified in four (3.7%) oncocytomas. Rare mitoses and focal coagulative necrosis were identified in two (1.8%) cases each. Focal clear cell changes were found in 16 (14.7%) oncocytomas, typically within hyalinized areas. Limited foci with chromophobe-like histology (not exceeding 5% of the neoplasm) were found in 13 (11.9%) oncocytomas. In 12 (11%) oncocytomas, rare papillary formations were noted in the lumina of microcysts. Significant nuclear atypia, oncoblasts and entrapped tubules were identified in 27 (24.8%), 41 (37.6%) and 40 (36.7%) neoplasms, respectively. After a median follow-up of 52 months (range 1-113 months), there was no disease recurrence, progression or death attributed to oncocytoma.

CONCLUSIONS

The recognition of the spectrum of morphological changes observed in renal oncocytoma should help pathologists establish a diagnosis of oncocytoma in problematic cases.

Two different renal cell carcinomas and multiple angiomyolipomas in a patient with tuberous sclerosis

We report a case of tuberous sclerosis associated with two histologically different renal cell carcinomas (RCCs) and multiple angiomyolipomas (AMLs) in the same kidney. A 43-year-old female was admitted to our hospital with left flank pain and a huge palpable mass in the left flank area. Abdominal computed tomography revealed two concurrent RCCs and multiple AMLs in the left kidney. Because of the clinical suspicion of RCC, the patient underwent left radical nephrectomy. On gross examination, the total size of the resected left kidney was 30.5×17×8 cm. Microscopically, the upper pole tumor features were consistent with chromophobe RCC and the midpole tumor was a clear-cell RCC. The multifocal masses in the remaining remnant parenchyma were AMLs. Six months after surgery, the patient is healthy without signs of tumor recurrence.

Unilateral simultaneous renal oncocytoma and angiomyolipoma: case report

A rare case of synchronous angiomyolipoma and oncocytoma in the same kidney of a 70 year old man is presented. A left renal mass was found incidentally by ultrasound. Computerized tomography and magnetic resonance imaging revealed a 1,3 cm mass in the mid-portion of the left kidney, whereas on the lower pole of the same kidney, a 3,3 cm mass was also revealed, consistent with angiomyolipoma. A working diagnosis of renal cell carcinoma was made. A radical nephrectomy was performed. Microscopically, the tumor of the lower pole was found to be an angiomyolipoma, whereas the mid-portion tumor was an oncocytoma. Until now, only 16 cases of unilateral simultaneous presence of renal angiomyolipoma and oncocytoma have been reported. Of these cases, all except one were female and three were associated with the tuberous sclerosis complex. It is well worth remarking, that renal oncocytoma overlap with other renal neoplasms, therefore nephrectomy remains the treatment of choice.Renal angiomyolipoma and oncocytoma are uncommon neoplasms and their simultaneous presence in the same kidney is rare. Only 16 cases have been reported until now in the literature. The purpose of this paper is to present an additional case without evidence of tuberous sclerosis.

Renal Oncocytoma in Taiwan

BACKGROUND

Renal oncocytoma has been repeatedly reported in Western countries, but only a few cases have been reported in Eastern countries. This study aims to review the clinical course of renal oncocytoma in an Eastern country such as Taiwan.

MATERIALS AND METHODS

Sixteen cases of renal oncocytoma seen between 1987 and 2002 at Chang Gung Memorial Hospital, Taipei, Taiwan, were studied.

RESULTS

Preoperatively, all patients were diagnosed to have renal cell carcinoma, following various radiologic studies. Perioperatively, frozen sections of three patients indicated renal oncocytoma in two and renal cell carcinoma in one. Renal oncocytoma has marked similarities to renal cell carcinoma, according to various radiologic, cytologic, and pathological investigations, so an accurate diagnosis is difficult to achieve, either preoperatively or perioperatively. Therefore, rather than being treated with partial nephrectomy, all patients were treated aggressively with unilateral radical nephrectomy. Postoperatively, all 16 patients were followed up, from 12 to 189 months, with a mean of 58.7 months. Notably, all patients survived with no evidence of tumor recurrence.

CONCLUSIONS

The experience in Taiwan is generally that renal oncocytoma behaves benignly, as reported in other areas. The excellent prognosis associated with this tumor appears to indicate that partial nephrectomy may suffice for removing the tumor, while sparing other unaffected renal parenchyma.

Hybrid renal cell carcinomas containing histopathologic features of chromophobe renal cell carcinomas and oncocytomas have excellent oncologic outcomes

BACKGROUND

Modern histopathology is able to differentiate chromophobe renal cell carcinomas (cRCCs), oncocytomas, and chromophobe-oncocytic hybrid RCCs; however, the true frequency and clinical courses of these tumors remain unclear.

OBJECTIVE

To determine the clinical course of hybrid RCC.

DESIGN, SETTING, AND PARTICIPANTS

Ninety-one surgically treated tumors, originally classified as oncocytoma or cRCC, were slide reviewed and reclassified by an experienced uropathologist. Immunohistochemical cytokeratin-7 (CK7) staining was used to distinguish oncocytoma (CK7 positive in <10% of the cells) and hybrid RCCs (CK7 positive in >10% of the cells).

INTERVENTIONS

Radical tumor nephrectomy or nephron-sparing surgery.

MEASUREMENTS

Recurrence-free and tumor-specific survival.

RESULTS AND LIMITATIONS

Overall, 16 tumors (17.6%) were hybrid RCCs, 32 tumors were cRCCs, and 43 tumors were pure oncocytomas. Perinephric tissue invasion (pT3a) was found in one pure oncocytoma and in two hybrid RCCs. The pathologic stage for cRCC was pT1 in 50% of tumors (n=17), pT2 in 23.5% of tumors (n=8), and pT3a in 26.5% of tumors (n=9). Low-grade RCC was found in 76.5% of tumors (n=26), and vascular invasion was found in 11.8% of tumors (n=4). After a mean follow-up of 50 mo, no oncocytomas or hybrid RCCs were found, but two cRCCs had recurred. The 3-yr tumor-specific survival rates for patients with oncocytoma, hybrid RCCs, and cRCC were 100%, 100%, and 97%, respectively.

CONCLUSIONS

Hybrid RCCs are more common than expected. The survival rate is 100% for both hybrid RCCs and oncocytomas. Hybrid RCCs may be candidates for active surveillance, and surgery may be unnecessary. CRCCs should be treated because a small proportion of these tumors exhibit aggressive clinical courses.

Renal oncocytoma: clinical experience of Taipei Veterans General Hospital

BACKGROUND

Renal oncocytoma has been reported mostly in the Western literature, and only a few cases have been reported in Eastern populations. In the present study, we review the clinical course of renal oncocytoma in our institution.

METHODS

We obtained the files of 13 cases of renal oncocytoma between 1988 and 2006 from the pathological archives of Taipei Veterans General Hospital. We retrospectively analyzed the patients' characteristics, clinical manifestations, surgical technique and clinical outcome.

RESULTS

The study population comprised 10 men and 3 women, and the mean age at diagnosis was 59.6 years (range, 37-75 years). Twelve patients (92%) were asymptomatic at presentation and were incidentally diagnosed to have renal tumor by sonography (9 patients), computed tomography (1 patient) or magnetic resonance imaging (2 patients), and 1 presented with hematuria. The clinical impression of oncocytoma was made preoperatively in only 3 patients by imaging studies, and most of the patients (76.9%) were diagnosed with renal cell carcinoma before surgery. Ten were treated with radical nephrectomy, 2 with partial nephrectomy, and 1 received excisional biopsy. All patients had unilateral solitary renal tumor; the right kidney was involved in 7 cases (54%) and the left in 6 (46%). Mean tumor size was 5.3 cm (range, 2.7-8.5 cm). Three patients were lost to follow-up in our series, and there was no recurrence or death (100% disease-specific survival) in the remaining 10 patients (77%) who were followed-up for a mean duration of 53.2 months (range, 10-117 months).

CONCLUSION

Renal oncocytoma has a benign clinical course with excellent long-term outcomes. Currently, nephron-sparing surgery is the mainstay of treatment, especially in patients with small tumors. However, accurate preoperative diagnosis based only on imaging studies is difficult, and radical nephrectomy was performed for most of the patients in our series.

Oncocitoma renal. Revisión de nuestra serie de 22 pacientes

Renal oncocytoma (OR) is a benign tumor. It may represent up to 3-7% of solid kidney masses, and shows specifics cellular and evolutive characteristics. Metacronicity, multifocality and bilateralism has been reported.

MATERIALS AND METHODS

Between 1986 and 2005, 478 kidney tumors have been surgically treated at our institution. We report the frequency and characteristics of OR in our patients, compared with renal cell carcinomas (RCC). We try to find out the rate of multifocality, bilateralism and other tumor association, and the number of neoplasms originally diagnosed as OR before surgery. Mean and median follow up: 36.86 and 13 months (1-193). Specific survival rate 100%.

RESULTS

We found 24 OR in 10 men and 12 women with a mean age of 59 years (34-84). 12 in the left kidney and 12 in the right one, one patient presenting oncocytomatosis. Tumor mean size was 4.64 cm (1-12.5 cm). Tumors were discovered incidentally in 17 cases. Presentation symptoms in the rest of patients were gross hematuria.

CONCLUSIONS

The rate of OR found in our sample population of renal tumors undergoing surgery matches other series already published. Two synchronic OR, but not metacronous, bilateral or metastatic tumors were found. All cases presented a benign evolution.

Renal oncocytoma: a clinicopathological analysis of 45 consecutive cases

OBJECTIVE

To evaluate the clinical behaviour and pathology of renal oncocytoma in a well-defined population over a 30-year period.

PATIENTS AND METHODS

In a retrospective population-based study we assessed relevant clinical and pathological factors in 45 patients (31 men and 14 women) diagnosed with renal oncocytoma in Iceland between 1971 and 2000. Clinical presentation, pathology, survival and causes of death were evaluated.

RESULTS

The age-standardized incidence was 0.3 per 100,000 per year for both men and women, the incidence of oncocytomas being 5.5% of renal cell carcinomas (RCCs) diagnosed during the same period in Iceland. Fourteen patients were diagnosed at autopsy for an unrelated disease. Of 31 living patients (mean age 70.5 years), seven were diagnosed incidentally (23%), and the others had presented with haematuria (32%), abdominal pain (29%), and weight loss (10%). All the patients had a radical nephrectomy, except for one with bilateral oncocytoma who had a partial nephrectomy. The mean (range) tumour size was 5.7 (0.9-12) cm. Eighteen patients (58%) were diagnosed at Tumour-Node-Metastasis stage I, 10 at stage II (32%) and three at stage III (10%), all of those at stage III having renal capsular penetration or tumour invasion into perirenal fat tissue (T3aN0M0). No patients were diagnosed with lymph node or distant metastasis. Two cases of coexisting RCC were detected. After a median follow-up of 8.3 years there were no recurrences or deaths from oncocytoma (100% disease-specific survival). The overall 5-year survival was 63%, with most patients dying from cardiovascular diseases or nonrenal cancers.

CONCLUSIONS

In most cases renal oncocytoma behaves like a benign tumour; the long-term prognosis is excellent. Thus, in the present patients, radical nephrectomy could be regarded as an over-treatment and nephron-sparing surgery as more appropriate, especially in patients with small tumours. However, both coexisting RCC and perirenal fat invasion, a hallmark of malignant behaviour, might indicate that more radical surgery is warranted in some of these patients.

Oncocytoma and synchronous urothelial carcinoma in same kidney: Previously unreported association

Many cases of histologically distinct renal tumors occurring coincidentally in the same patient have been reported. We report the first case of a benign oncocytoma and a urothelial carcinoma occurring synchronously in the same kidney in a man who underwent radical nephrectomy for a suspicious renal mass. The patient subsequently underwent distal ureterectomy.

[Renal oncocytoma. Three case reports]

Renal oncocytoma represents a rare benign tumor accounted for 3-5% of renal neoplasms. It has been mistaken for and mistabled as granular or dark cell carcinoma. Between 1993 and 1998, 3 women with renal oncocytoma were recognized at formation and underwent radical nephrectomy. Sonography and the CT scan was performed but the Accurate diagnosis was not possible before performing surgery and histologic investigations. The mean Follow-up of 3 patients was 48 month and showed a benign clinical behaviour in all cases.

Update on oncocytoma

Oncocytoma is the most common benign solid renal tumor, comprising roughly 5% of resected renal masses. Typically discovered incidentally, oncocytoma is generally asymptomatic and very rarely metastasizes; however, multifocal disease and coexistence with renal cell carcinoma can occur. No currently used imaging techniques can reliably distinguish between oncocytoma and malignant lesions; therefore, patients must undergo resection, or in certain circumstances, biopsy, to definitively establish diagnosis. Careful attention to pathologic features and the adjunctive use of immunostains can aid in discriminating oncocytoma from other renal tumors characterized by granular, eosinophilic cytoplasm, especially chromophobe renal cell carcinoma. Nephron-sparing and laparoscopic surgical approaches can be used to treat appropriately selected patients.

Prognostic impact of histologic subtyping of adult renal epithelial neoplasms: an experience of 405 cases

Just two and a half decades ago adult renal cell neoplasms, i.e., those arising from the renal tubules or collecting duct epithelium, were subdivided into two major subtypes: "clear cell carcinoma" and "granular cell carcinoma." Subsequent detailed morphologic and/or cytogenetic studies have resulted in the recognition of several distinctive subtypes of adult renal epithelial neoplasms, which has led to the promulgation of a refined contemporary histologic classification of these tumors. This study examines the prognostic significance of histologic subtyping in accordance with the new classification in a consecutive series of 405 cases treated at a single institution. Cases were histologically classified into 28 (7%) benign tumors [27 (6.7%) renal oncocytomas, 1 (0.2%) metanephric adenoma] and 377 (93%) malignant tumors [255 (63%) conventional (clear cell) renal cell carcinoma, 75 (18.5%) papillary renal cell carcinoma, 24 (5.9%) chromophobe renal cell carcinoma, and 23 (5.7%) renal cell carcinoma, unclassified]. A total of 25 (6.6%) malignant tumors showed evidence of sarcomatoid change. Kaplan-Meier survival analysis with log-rank test showed histologic type (p = 0.002), Fuhrman's nuclear grade (p = 0.001), TNM stage (p = 0.001), vascular invasion (p = 0.001), and necrosis (p = 0.001) to be significantly associated with disease-specific survival and progression-free survival, based on follow-up of 368 patients (mean 64.5 months, median 56 months). The 5-year disease-specific survival for chromophobe renal cell carcinoma, papillary renal cell carcinoma, conventional (clear cell) renal cell carcinoma, and renal cell carcinoma, unclassified was 100%, 86%, 76%, and 24%, respectively; no patient with a benign tumor diagnosis progressed or died of disease. The 5-year progression-free survival for chromophobe renal cell carcinoma, papillary renal cell carcinoma, conventional (clear cell) renal cell carcinoma, and renal cell carcinoma, unclassified was 94%, 88%, 70%, and 18%, respectively. Malignant tumors with sarcomatoid change had a 35% and 27%, 5-year disease-specific and progression-free survival, respectively. Cox proportional hazards regression analysis showed TNM stage (p = 0.001), nuclear grade (p = 0.01), and necrosis (p = 0.05) to be significant predictors of disease-specific survival. In conclusion, our study shows that the histologic categorization of adult renal epithelial neoplasms performed by routine light microscopic hematoxylin and eosin-based examination in accordance with the contemporary classification scheme has prognostic utility.

[Kidney oncocytoma. Report of 7 cases]

Renal oncocytoma has some particularities in diagnosis and prognosis. We report a retrospective study performed between 1987 and 1999 at the department of Urology of Charles Nicolle's Hospital. Seven oncocytoma are found out of 120 renal carcinoma. Features at sonography or CT scan or arteriography can not suggest oncocytoma. The diagnosis is made at the pathology examination. Renal oncocytoma is a benign tumor. Conservative surgery will be performed as possible.

Giant renal oncocytoma

We report the largest renal oncocytoma excised at the initial presentation and the second largest renal oncocytoma in published reports. Despite a tendency for renal oncocytomas to be relatively small and asymptomatic compared with renal cell carcinomas, these lesions cannot be reliably differentiated preoperatively. The variable nature of presentation and overlap of radiographic characteristics between these lesions complicates their clinical differentiation. The present case illustrates the difficulty in the preoperative diagnosis of even very large, enhancing renal masses and reinforces the inclusion of renal oncocytoma in the differential diagnosis of these lesions.

Specific von Hippel-Lindau protein expression of clear cell renal cell carcinoma with "immunogenic" features

Human clear cell renal cell carcinoma (CCRCC) is characterized by specific von Hippel-Lindau (VHL) gene alterations and immunogenic features. In the present study, the immunohistochemical expression of the von Hippel-Lindau gene protein (pVHL) was compared with the presence of major histocompatibility complex (MHC I-II), tumor infiltrating lymphocytes (TIL) and tumoral immune complexes (TIC) in CCRCC. Native tumor tissues of 132 RCC patients (95 with the common clear cell subtype), diagnosed according to the Heidelberg classification, were obtained for immunohistochemistry. Tumor stainings with pVHL, MHC I-II and tumor infiltrating lymphocytes (T and B lymphocytes, monocytes) were detected by immunoperoxidase methods using monoclonal antibodies. Tumoral immune complexes (IgG, IgA, IgM and C1q, C3 complement proteins) were visualized by fluorescent polyclonal antibodies. Immune stainings were semiquantitatively evaluated. Specificity and sensitivity of these markers in relation to the common histological subtype of RCC (CCRCC) were calculated. CCRCC was characterized by specific pVHL expression. At the same time, CCRCC was associated with constitutional MHC I-II expression and highly specific degree of TIL and TIC. It is concluded that specific pVHL expression of CCRCC is frequently associated with immunogenic features. Immunohistochemical analysis aims the initial tumor staging of RCC patients to achieve better patient selection for immunotherapy. However, the association of pVHL expression with the immunogenic CCRCC is statistically relevant, the mechanism and its clinical relevance in immunotherapy still remains to be tested.

Prognostic histological and immune markers of renal cell carcinoma

Recent development on the fields of molecular genetics and immunology of human renal cell carcinoma (RCC) have resulted in more successful treatment of advanced and metastatic RCCs. Re-evaluation of the prognostic/predictive data aim the initial tumor staging of RCC patients to achieve better patient selection for immune and gene therapy. 125 RCC patients diagnosed according to the Heidelberg histological classification, graded, Robson staged, immune treated (Interferon-a a+ Vinblastine or Broncho-Waxom/Decaris) were followed-up clinically for 36 months. Tumor immunity markers by immunohistochemistry of tumor infiltrating lymphocytes (TIL) were detected by immunoperoxidase methods using monoclonal antibodies. Tumoral immune complexes (TIC) were visualized by fluorescent polyclonal antibodies. Histologically oncocytomas defined a better (p<0.02) and sarcomatous RCCs a worse (p<0.01) follow-up prognosis. Basically, the metastatic status (related with the stage and grade) determined the clinical outcome (p<0.00002) of the RCC patients. Tumoral immune complexes (TIC) were weak positive, while tumor infiltrating lymphocytes (TIL) weak negative predictors of the succes of Broncho-Waxom/Decaris immune therapy. Molecular genetic based histological classification, grade, stage and metastatic status parameters together with some tumor immunity parameters (TIL, TIC) can predict the success of immunotherapy of RCC patients.

Renal oncocytoma: diagnostic and therapeutic aspects

Renal oncocytoma is one of the most unusual benign lesions, which presents as a complicated mass resulting in a diagnostic and therapeutic dilemma. A new case of renal oncocytoma in a 13-year-old boy is presented. The clinocopathologic features of this rare entity are discussed, with special emphasis on diagnosis and treatment. There are no specific presumptive clinical and laboratory findings, including tumor markers, ploidy analysis, and imaging techniques that distinguish oncocytoma from other renal masses. The most important diagnostic aid is to bear this entity in mind when a child presents with an unexplained renal mass. Frozen section biopsies followed by partial nephrectomy are mandatory for the appropriate treatment after excluding bilateral or multifocal occurrence.

Use of antibodies to RCC and CD10 in the differential diagnosis of renal neoplasms

The majority of renal neoplasms can be distinguished on the basis of histologic examination alone; however, there are morphologic similarities between clear cell renal carcinoma and chromophobe cell carcinoma, as well as between the granular/eosinophilic variants of these tumors and renal oncocytoma. Only a limited number of histochemical markers are available to aid in the differential diagnosis of these neoplasms. Hale's colloidal iron usually yields strong, diffuse cytoplasmic staining of chromophobe cell carcinomas whereas clear cell carcinomas are generally negative; however, interpretation of this stain is not always straightforward. By immunohistochemistry, vimentin is detectable in most clear cell carcinomas and is absent from most chromophobe cell tumors and oncocytomas, but reliance on a single antibody can be misleading. In this report we examine the use of commercially available monoclonal antibodies to RCC and CD10 in the differential diagnosis of common renal tumors. Eighty-five percent of clear cell carcinomas (53 of 62) had detectable surface membrane staining for RCC, and 94% (58 of 62) were positive for CD10. Papillary carcinomas were likewise strongly positive for RCC and CD10 in nearly all cases (13 of 14 each). In contrast, all 19 chromophobe cell carcinomas examined were completely negative for surface membrane staining with both of these markers. Oncocytomas were also negative for RCC (0 of 9), but CD10 was detectable in some cases (3 of 9). These results suggest that the presence of surface membrane staining for RCC and CD10 may be used to confirm a diagnosis of suspected clear cell or papillary renal carcinoma. Chromophobe cell carcinomas should be negative for both markers. The absence of RCC staining may also be helpful in the diagnosis of renal oncocytoma.

Renal oncocytoma: multifocality, bilateralism, metachronous tumor development and coexistent renal cell carcinoma

PURPOSE

We analyzed a large series of cases of renal oncocytoma to define the incidence of coexistent renal cell carcinoma, multifocality, bilateralism and metachronous tumor development.

MATERIALS AND METHODS

Between 1980 and 1997, 100 men and 38 women with a mean age of 68 years with oncocytoma, were treated surgically at our institution. We analyzed tumor characteristics and reviewed specimens for coexistent renal cell carcinoma.

RESULTS

Tumors were discovered incidentally in 58% of the cases. Specimens were obtained from 84 radical and 70 partial nephrectomies. Tumor size ranged from 0.3 to 14.5 cm. (median 3.2). Oncocytoma was unilateral in 131 cases (95%) and bilateral in 7 (5%), while there were multiple oncocytomas in 8 (6%). Mean followup was 41 months (range 0 to 200). The disease specific survival rate was 100% and no patient had metastasis. In 6 patients (4%) metachronous oncocytoma developed during followup. No patient had locally recurrent oncocytoma after partial nephrectomy for a solitary renal oncocytoma. Renal cell carcinoma and oncocytoma were found in 14 patients (10%), including unilateral synchronous disease in 9 and bilateral synchronous disease in 5.

CONCLUSIONS

Our data support the benign nature of renal oncocytoma. Multifocality, bilateralism and metachronous tumor develop in approximately 4 to 6% of all cases. Renal cell carcinoma coexisted in 10% of oncocytoma cases.

Renal oncocytoma: a clinicopathologic study of 70 cases

We reviewed 954 primary nonurothelial epithelial renal neoplasms with primary resection at Memorial Sloan-Kettering Cancer Center between the years 1980 and 1995 and classified 70 cases (7%) as renal oncocytomas. The study population was composed of 39 men and 31 women, and the mean age was 65 years (range 25 to 86 years). Fifty-six patients (80%) were asymptomatic at presentation, six (4%) had flank pain, six (4%) presented with a mass, and two (3%) had hematuria. Sixty-one were treated with total or radical nephrectomy, nine with partial nephrectomy. The right kidney was involved in 35 cases (50%), the left kidney in 32 (46%). Three cases (4%) were bilateral. Sixty-one cases (87%) were unifocal, nine (13%) multifocal. All the tumors were well circumscribed but unencapsulated. Forty-five (64%) were described as brown or red, whereas the remainder were variously described as tan to yellow. Central fibrosis or scar was described in 23 cases (33%), and gross areas of hemorrhage or cystic changes in 14 (20%). The mean size was 5.2 cm and median 5.0 cm (range 1.5 cm to 14 cm). Histologically, the tumors were characterized by a mixture of architectural patterns: compact cellular nests and acini embedded in a hyalinized, hypocellular stroma were present in 62 cases (89%), a solid nested architecture in 47 cases (67%), and a variable tubular component in 50 cases (71%). Small papillae, pseudopapillae, and intratubular epithelial tufts were seen in 19 cases (27%). Cytologically, the neoplasms also showed a mixture of cell types, the most common being the classic oncocyte, which consisted of round or polygonal cells with moderate to abundant granular, eosinophilic cytoplasm, and small round nuclei with evenly dispersed granular chromatin. Small basophilic nucleoli were visible in many of these cells in all cases. Thirty-one cases (44%) had a variable number of oncocytic cells with pyknotic nuclei and 20 (30%) contained clusters of small cells with a high nuclear/cytoplasmic ratio and dense hyperchromatic nuclei (so-called oncoblasts). Foci of tubules with clear cells embedded in a hyalinized stroma were present in six cases (9%). Cellular atypia was evident in 42 cases (60%) and was marked in 21 (30%). Eleven cases (16%) exhibited mitotic activity, albeit low. No case had atypical mitoses or necrosis. Twenty-two cases (31%) had areas of calcification within the hyalinized stroma, 12 (17%) had calcospherites, and three (4%) had osseous and myeloid metaplasia. Vascular invasion was present in three cases (4%), and invasion of perinephric fat in 14 (20%). One patient presented with liver metastasis. Fourteen cases (20%) were pT1, 42 (60%) pT2, and 14 (20%) pT3. After a mean follow-up of 58 months (range 1 to 181), 62 patients (89%) were alive with no evidence of tumor, six (9%) had died of other causes, one was alive with stable metastatic disease in the liver 58 months after diagnosis, and one died with metastatic disease to bone and liver. We conclude that renal oncocytomas have a varied morphologic appearance and their pathologic diagnosis should be based on a constellation of architectural and cytologic features. The overwhelming majority of cases behave in a benign fashion, although in rare instances they can metastasize. The presence of atypical morphologic features do not alter the excellent prognosis associated with oncocytomas and do not predict an aggressive clinical course.

Rare association of unilateral renal oncocytoma and angiomyolipoma

A 65-year-old woman presented to the hospital with left loin pain and haematuria, radiological diagnostic studies demonstrated left renal mass suggestive of renal cell carcinoma and radical nephrectomy was performed. Pathological examination demonstrated the very rare association of renal angiomyolipoma and oncocytoma.

Renal oncocytoma: a reappraisal of morphologic features with clinicopathologic findings in 80 cases

Renal oncocytoma has several features that overlap with other renal neoplasms with a preponderance of granular cytoplasm, such as chromophobe, granular, and papillary renal cell carcinomas. Lack of knowledge of this entire spectrum of eosinophilic renal cell neoplasms has led to several misconceptions in the literature regarding renal oncocytoma. These include the "grading of oncocytomas," "metastatic oncocytomas," and the impression that renal oncocytoma is usually low grade and lacks prominent nucleoli. In order to further characterize the histologic features and embelLish diagnostic criteria, we evaluated 93 tumors from 80 patients. Four tumors were bilateral and two were multifocal. The mean age was 67.2 years (32-89 years), men were more commonly affected (3.1:1), and 82.7% tumors were incidental findings. Grossly, the tumors were mahogany brown, lacked necrosis, and averaged 4.4 cm in size (range 0.6-15 cm). Histologically, renal oncocytoma was composed of an exclusive or predominant component of acidophilic cells with three architectural patterns of disposition: (a) The "classic" pattern (57.5%), composed of a characteristic nested or organoid arrangement of cells, each surrounded by a distinct reticulin framework; (b) a "tubulocystic pattern" (6.3%) with numerous closely packed cystically dilated tubular structures; and (c) "mixed pattern" (36.2%), which had both the organoid and tubulocystic patterns. A gross or microscopic scar was noted in 53.8% cases, and histologically a distinctive myxoid and/or hyalinized stroma separated nests of cells. Generally, the nuclei of renal oncocytoma were round with uniform nuclear contours. Nearly half of the tumors had prominent nucleoli (42.5% had prominent nucleoli equivalent to Fuhrman's grade III or IV). Pleomorphism was absent in 50% of cases but was conspicuous in 12.5% of cases including foci of bizarre cells. Other atypical features included perinephric fat involvement (11.3%), renal parenchymal invasion not associated with desmoplasia (10%), and hemorrhage (31.3%). Renal oncocytoma by definition lacks areas of clear cell carcinoma, significant lesional necrosis, or conspicuous papillary formations. Ancillary features noted included normal-appearing renal tubules within the lesion (15%), intranuclear holes (20%), psammoma bodies (7.5%), and foam cells (7.5%). 15% of tumors were locally excised, and 85% resulted in radical nephrectomy. Mean follow-up of 7.6 years (range 15-200 months) showed no evidence of recurrence, metastasis, or death due to tumor. In conclusion, renal oncocytoma, herein described, is a benign neoplasm and therefore does not merit a nuclear grading scheme. It has unique histologic features including an organoid and tubulocystic architecture, myxoid or hyalinized stroma, and occasionally some atypical findings including nuclear pleomorphism, prominent nucleoli, and adjacent renal parenchymal and perinephric fat involvement.

Renal oncocytoma: preoperative diagnosis using technetium 99m sestamibi imaging

OBJECTIVES

To determine if 99mTc-sestamibi (technetium 99m-methoxyisobutylisonitrile) can be used preoperatively to differentiate renal oncocytomas from other renal masses.

METHODS

We performed 99mTc-sestamibi scans on 6 patients with various renal masses, using a standard technique. The diagnosis in each patient was determined either by radiologic methods.

RESULTS

There was significantly increased uptake in the patient with the renal oncocytoma, whereas the other lesions had decreased uptake in comparison to normal kidney. This was determined visually and by mean pixel analysis.

CONCLUSIONS

Technetium 99m sestamibi scanning appears to have a potential role in the nonoperative diagnosis of renal oncocytomas, in combination with pathologic fine-needle biopsy confirmation. More definitive pathologic experience is required before recommending standard use.

Renal oncocytomatosis

Renal oncocytoma is an uncommon benign renal neoplasm of unknown etiology. Bilateral, multicentric renal oncocytomas are rare and diffuse renal oncocytomas are even rarer. We report a patient with incidentally detected marked bilateral nephromegaly due to innumerable oncocytomas. The term "oncocytomatosis" should be strictly applied to cases in which oncocytomas diffusely infiltrate the kidneys.

Management of small unilateral renal cell carcinomas: radical versus nephron-sparing surgery

OBJECTIVES

There is controversy concerning the management of small unilateral renal cell carcinomas. The present study was undertaken to evaluate the relative efficacy of radical nephrectomy versus nephron-sparing surgery in such patients.

METHODS

Patients with a single, small (less than 4 cm), localized, unilateral, sporadic renal cell carcinoma (RCC) were identified from an institutional registry. From 1975 to 1992, 88 patients fulfilling these criteria were treated with either radical nephrectomy (n = 42) or nephron-sparing surgery (n = 46). The mean postoperative follow-up interval is 48 +/- 29 months.

RESULTS

The radical and nephron-sparing surgical groups were well matched for patient age, sex, renal function, diabetes, hypertension, tumor size, tumor location, and tumor stage. All patients in both groups had low pathologic stage RCC. There was no difference between the two groups in terms of the mean hospital stay, the requirement for blood transfusions, or the occurrence of surgical complications. There was no difference in the mean preoperative and postoperative serum creatinine levels for patients in the nephron-sparing surgery group. However, the mean postoperative serum creatinine levels were significantly higher than the mean preoperative levels for patients in the radical nephrectomy group (P < 0.001). A single patient in each group developed recurrent RCC postoperatively. The cancer-specific 5-year survival rate for patients in the radical and nephron-sparing surgical groups is 97% and 100%, respectively.

CONCLUSIONS

Radical nephrectomy and nephron-sparing surgery each provide safe and effective curative treatment for patients with a single, small, unilateral localized RCC. The long-term renal functional advantage of nephron-sparing surgery in this setting is not established.