Renal oncocytoma—bilateral,multifocal

One hundred thirteen cases of “grade I renal oncocytoma” are reported from several centers. All centers report absence of associated metastatic disease. In the present review of 219 radical nephrectomy specimens, 11 renal oncocytomas were identified, an incidence of 5 per cent. No diagnostic angiographic features could be identified. Multifocal potential is exemplified by study of a bilateral case and 2 cases of 2 independent oncocytomas in the same kidney. The fine histologic criteria distinguishing oncocytoma from malignant renal tumors suggest that the oncocytomas may have the potential of malignant degeneration. The possible “premalignant classification” of oncocytomas and the lack of dependable diagnostic features radiographically force the management to be the same as for Stage I renal carcinoma. The prognostic information available after histologic definition of renal oncocytoma is valuable.     

A case of renal oncocytoma with synchronous contralateral renal cell carcinoma

A case of bilateral, synchronous renal cell carcinoma and oncocytoma is reported. The patient was a 70-year-old woman. Computed tomographic scan revealed bilateral low density masses, which had a diameter of approximately 4 cm (right kidney), and 2.5 cm (left kidney). We suspected bilateral renal cell carcinomas, and performed, right nephrectomy and left enucleation of the tumor. Pathological diagnosis was right renal cell carcinoma and left oncocytoma. To our knowledge only 5 previous cases of renal cell carcinoma associated with oncocytoma have been reported in Japan. Two cases were metachronous and three cases were unilateral and synchronous. This is the first reported case of bilateral, synchronous renal cell carcinoma and oncocytoma.     

肾嗜酸细胞腺瘤的临床诊治分析

目的提高肾嗜酸细胞腺瘤(renal oncocytoma,RO)的诊疗水平。方法回顾分析13例RO患者临床资料。13例患者中,男4例,女9例;肿瘤单发12例,单侧多发1例;肿瘤最大直径为1.0～6.9cm,平均3.3cm;肿瘤位于左肾上极2例,左肾中极2例,左肾下极3例,右肾上极4例,右肾中极1例,右肾下极1例。所有患者术前均行B超、IVU检查,12例行CT检查,3例行MRI检查。结果 12例术前诊断为肾癌,1例考虑为RO。13例中8例行根治性肾切除术,5例行肾部分切除术。术后病理均证实为RO。随访1～183个月无肿瘤复发或转移。结论 RO是一种临床少见的良性肿瘤,术前确诊较困难,与肾癌较难鉴别,诊断有赖于病理组织学和免疫组化检查,保留肾单位手术为首选治疗方法。     

Renal oncocytoma with bilateral synchronous renal cell carcinoma in a patient undergoing long-term hemodialysis

Abstract:   We report a case of bilateral synchronous renal cell carcinoma and renal oncocytoma in a 56-year-old male who had been treated with hemodialysis for 32 years. Because anemia gradually worsened, computed tomography and magnetic resonance imaging were carried out and revealed bilateral renal tumors within acquired cystic disease of the kidney. Bilateral nephrectomy was carried out, and the patient was diagnosed with multiple renal cell carcinomas and a single renal oncocytoma. To our knowledge, this is the first reported case of renal oncocytoma with synchronous renal cell carcinoma in a patient undergoing long-term hemodialysis.     

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.     

Preoperative diagnosis of renal oncocytoma and treatment possibilities

We report 2 cases of renal oncocytoma and review the literature. A number of radiological, cytological and ultrastructural differential features of oncocytoma that are known today make preoperative diagnosis of this tumour possible. Analysis of the reported cases allows to conclude that oncocytomas are of universally benign character with a very good prognosis. Metastases have not been documented. Thus we suggest that many patients with oncocytoma could be spared the operation of nephrectomy. Partial kidney resection or heminephrectomy are to be preferred with solitary oncocytomas of a moderate size.     

后腹腔镜保留肾单位的肾部分切除术治疗T1期肾肿瘤（附22例报道）

目的探讨后腹腔镜保留肾单位的肾部分切除术治疗T1期肾肿瘤的手术方法及临床疗效。方法回顾性分析22例行后腹腔镜保留肾单位的肾部分切除术的T1期肾肿瘤患者的临床资料,其中男8例,女14例,平均年龄48岁。双侧肾肿瘤1例,单侧双瘤灶1例;左侧13例,右侧10例。肿瘤平均直径3cm。所有患者均行后腹腔镜保留肾单位的肾部分切除术。结果 22例手术均顺利完成。平均手术时间135min,平均肾动脉阻断时间29min,平均出血量55ml,平均住院时间10d。术中未见外科并发症,术后仅1例发生漏尿。术中切缘组织病理均阴性。24个瘤灶术后病理证实为肾透明细胞癌19例、多房囊性肾细胞癌2例、肾嗜酸细胞瘤2例、肾嫌色细胞腺癌1例。随访时间1～28个月,平均10个月,肿瘤无局部复发及远处转移。结论后腹腔镜保留肾单位的肾部分切除术治疗T1期肾肿瘤安全、可行,其远期疗效尚待长期随访。     

Renal cell carcinoma in solitary kidneys

We report 10 cases of renal tumors in a solitary kidney that were treated surgically with efforts to spare renal function. Three patients were rendered anephric to excise completely the renal cancer and 2 remain without disease. The remaining 7 patients had complete tumor excision with the aid of partial nephrectomy. One patient had bilateral oncocytomas. Of the 6 partial nephrectomy patients with cancer 1 (18 per cent) remains free of metastatic disease. Concern is expressed for the role of partial nephrectomy as curative surgery for renal cancer.     

Renal oncocytoma with synchronous contralateral renal cell carcinoma

A 60-year-old male was admitted with bilateral renal masses with a diameter of 50 mm (right kidney), and 15 mm (left kidney) found incidentally by computed tomography. Renal angiography demonstrated neovascularization in the lower pole of the right kidney, but no remarkable findings in the left kidney. We could not deny the possibility of bilateral renal cell carcinoma. Right radical nephrectomy and left partial nephrectomy were performed. The histopathological finding revealed diagnosis of right papillary renal cell carcinoma and left oncocytoma. To our knowledge, this is the third case of renal oncocytoma with synchronous contralateral renal cell carcinoma reported in Japan.     

Does the finding of a indeterminate mass lesion in screening CT result in kidney loss and is postoperative follow-up necessary in renal encocytomas? A retrospective study

OBJECTIVE: Sixteen patients who were operated on with a preoperative diagnosis of renal tumor were diagnosed with renal oncocytoma between 1991 and 2004. The reliability of preoperative diagnosis, the role of screening CT in organ preservation and the need for follow-up for renal oncocytomas are discussed in the light of literature findings. MATERIAL AND METHODS: Among 345 patients diagnosed with renal tumors in the previous 13 years, the clinical and radiological features of the 16 patients with renal oncocytomas and the results during the postoperative follow-up period were evaluated in this retrospective study. The female:male ratio was 4.3. Two of the patients complained of hematuria whereas the other 14 experienced lumbocostal pain. The mean dimensions of the tumors on CT scans were 5.7+/-2.88 cm. Central fibrous scarring existed in three patients. Two patients underwent tumor enucleation, three underwent partial nephrectomy and 11 underwent radical nephrectomy. RESULTS: Screening CT could not achieve a precise preoperative differential diagnosis from malignant renal mass. The organ preservation ratio was approximately 1:3 based on the radiological diagnosis. Screening CT scans showed oncocytomas with diameters greater than those reported in the literature, indicating a need for urgent nephrectomy. No recurrences, metastases or deaths due to renal oncocytoma were observed in the postoperative follow-up period (mean 6.7+/-4 years; range 1-13 years). CONCLUSIONS: Preoperative diagnosis of renal oncocytoma is very difficult. The postoperative follow-up period in our series was 13 years, which is significantly longer than the duration proposed in the literature.     

The Ron proto-oncogene product is a phenotypic marker of renal oncocytoma

The proto-oncogene product Ron is the receptor for macrophage stimulating protein, a scatter factor that stimulates cell proliferation, prevents apoptosis, and induces an invasive cell phenotype. We investigated the expression of Ron, Ki-67 (proliferation index), p53, and bcl-2 (proapoptotic and antiapoptotic proteins, respectively) in 50 renal tumors (19 clear cell carcinomas, 18 oncocytomas, 7 papillary cell carcinomas, 5 chromophobe cell carcinomas, and 1 carcinoma with sarcomatoid areas). In addition, we studied Ron in normal kidney and in the renal carcinoma cell line Caki-1. Immunostaining and Western blot showed Ron in normal kidney and in all oncocytomas but never in renal cell carcinomas or in Caki-1. In addition, Western blot showed that Ron was expressed in phosphorylated, i.e., active, form. Bcl-2 was strongly expressed in oncocytomas, whereas Ki-67 and p53 were much less expressed in oncocytomas than in carcinomas. These results indicate in Ron a marker that differentiates oncocytoma from the other renal epithelial tumors. We therefore think that Ron may prove to be a new tool for a sound and precise diagnosis of oncocytoma, a benign tumor that cannot always be distinguished from carcinomas at histologic examination. The overexpression of bcl-2, but not p53 in oncocytoma, suggests that the MSP/Ron system sustains the growth of oncocytoma by opposing apoptosis.     

Renal oncocytoma: a diagnostic and therapeutic dilemma

From 1968 to 1983, 254 patients underwent an operation for presumed renal cell carcinoma. In this retrospective review the pathological diagnosis was renal oncocytoma in 11 patients (4 per cent). Renal oncocytomas were present bilaterally in 2 patients, including 1 with a coexisting renal cell carcinoma. In 2 other patients the oncocytomas were multicentric. The angiographic, computerized tomographic and sonographic findings in these patients typified renal cell carcinoma. Surgical treatment comprised radical or partial nephrectomy for unilateral and bilateral lesions, respectively. Because of the benign nature, multicentricity, possible bilaterality and absence of pathognomonic radiographic features, renal oncocytomas should be considered in the differential diagnosis of solid renal masses.     

Renal cell carcinoma vs. renal oncocytoma. Report of a case with overlap features and review of the literature

Although the salient features of renal oncocytomas and renal cell carcinomas have been discussed in the recent literature, renal masses with features of both entities will present diagnostic difficulty, especially when the cells are diffusely eosinophilic on microscopic examination. A case of a firm, tan, rounded mass replacing the lower pole of the kidney is discussed. The final diagnosis of renal cell carcinoma, granular cell type, was made after multiple sections of the tumor were examined, and after electron microscopy was performed. A thorough search by light microscopy should be made for clear cell foci, necrosis, mitotic activity, and vascular or capsular invasion, features generally accepted as pathognomonic for renal cell carcinoma. Cellular and especially nuclear pleomorphism is typically focal or mild in renal oncocytomas. True oncocytic tumors will be packed with mitochondria on electron microscopy; however, granular renal cell carcinomas will contain mitochondria as well as other cellular organelles, lipid, and glycogen. Electron microscopy should be performed on tumors suspected of being oncocytomas because eosinophilia on hematoxylin and eosin stain, as demonstrated by this case, is not a predictable measure of mitochondria content. Immunoperoxidase staining for vimentin in oncocytomas has recently been shown to be negative, and may offer a method of ruling out oncocytoma in vimentin-positive tumors, pending further studies.     

Renal cell carcinoma associated with tuberous sclerosis: a case report

Renal angiomyolipoma associated with tuberous sclerosis is well known. On the other hand, few cases of renal cell carcinoma in connection with tuberous sclerosis have been reported. We report a patient with tuberous sclerosis whose kidney was involved with renal cell carcinoma. A 18-year-old woman was first admitted in August 1987 for evaluation of left renal tumor. Diagnosis of tuberous sclerosis was made when she was 11 years old on the basis of mental retardation, papules on her face, seizures, white leaf-shaped macules and periventricular calcifications. Computerized tomographic scan demonstrated a large mass arising from the left kidney and small masses in the right kidney. Angiography confirmed bilateral hypervascular renal tumors. On these bases, a clinical diagnosis of bilateral renal angiomyolipomas was made and surgical treatment of the left kidney was recommended because of its large size. However, her parents did not permit treatment until March, 1988. Finally, left nephrectomy of 4,750 g was performed and histological examination revealed renal cell carcinoma with clusters of spindle cells. In the literature available to us, we found twelve reports of malignant renal tumors associated with tuberous sclerosis including five renal cell carcinomas in Japan.     

Renal oncocytoma

Summary A decade has now passed since renal oncocytoma became a diagnosis of acute interest to urologists, radiologists and pathologists. The number of patients with renal oncocytoma continues to increase; now a total of over 340 reported cases are available for analysis. Approximately 3% of tumors previously diagnosed as renal cell carcinomas are now considered to be renal oncocytomas. The overwhelmingly benign clinical behavior of typical renal oncocytomas seems well established. At present, there is no definitive way to make the diagnosis of renal oncocytoma preoperatively. Because renal oncocytomas are not so rare, clinicians dealing with solid renal tumors must keep in mind this diagnosis and its possible bilateral and multifocal occurrence. Conservative renal parenchyma sparing operations for oncocytomas should be encouraged.     

肾脏嗜酸细胞腺瘤6例报告

目的：探讨肾脏嗜酸细胞腺瘤的临床特征。方法：报告6例本病患者的临床资料，5例无临床表现，经B超体检偶然发现“肾脏占位”；1例腰痛、腰部不适、触及腹部包块。CT、IVU等影像学检查均有阳性发现。行肾脏部分切除术2例，根治性肾脏切除术4例。术中快速冷冻病理检查确诊。结果：6例术后均痊愈。随访13～96个月，平均78．6个月，2例随访时间未满5年，4例已超过5年（60个月），均未见肿瘤复发和转移。结论：肾脏嗜酸细胞腺瘤是一种少见的良性肿瘤，多无临床表现；影像学检查均有阳性发现；确诊有赖于病理检查，术中快速冷冻病理检查对确定术式有帮助。     

Nephron sparing surgery for central renal tumors: experience with 33 cases

PURPOSE: Nephron sparing surgery is standard treatment for small, peripherally located renal cell carcinoma. In patients with a solitary kidney, bilateral tumors or impaired renal function nephron sparing surgery provides the only option to nephrectomy and subsequent hemodialysis or transplantation. We retrospectively investigated the value of nephron sparing surgery for centrally located renal cell carcinoma. MATERIALS AND METHODS: Between 1969 and 1997, 311 renal tumor enucleations were performed at our institution. The tumor was centrally located in 33 cases. The indication for enucleation was elective in 7 cases and imperative in 26, including bilateral tumor in 16 (metachronous in 9 and synchronous in 7), chronic renal failure in 4 and solitary kidney in 6. Four patients had metastasis at enucleation. RESULTS: Convalescence was unremarkable in 28 cases. Hemorrhage occurred in 1 patient, a urinary fistula in 2 and a local abscess secondary to a urinary fistula in 1. One patient died postoperatively of heart failure. Average serum creatinine was 1.25, 1.63 and 1.33 mg./dl. preoperatively, at hospital discharge and at a mean followup of 33 months, respectively. Hemodialysis was necessary transiently during convalescence in 1 patient and permanently starting 6 years after enucleation in another. Definitive histology revealed oncocytoma in 4 cases and renal cell carcinoma in 29. Disease was stages pT1 to pT3 in 9, 18 and 2 cases, and grades 1 to 3 in 6, 18 and 5, respectively. Local recurrence developed in 2 patients. Mean followup was 5.2 years (range 0.3 to 16.7). At a mean followup of 6.2 years (range 0.7 to 16.7) 20 patients were free of disease. In addition to the patient who died postoperatively, 9 died of renal cell carcinoma at a mean of 1.6 years (range 0.3 to 5.3) and 3 died of other causes at 5, 11 and 12 years postoperatively, respectively. No patient who underwent elective enucleation died. CONCLUSIONS: Nephron sparing surgery for centrally located kidney tumors is technically feasible and associated with an acceptable complication rate. Local tumor control is excellent, and the overall prognosis depends on contralateral disease and metastasis. Benign tumors may be diagnosed and removed without loss of the kidney. By avoiding hemodialysis quality of life is improved.     

Solitary pancreatic metastasis from renal cell carcinoma

A case of asynchronous bilateral renal cell carcinoma with pancreatic metastasis is described. Left nephrectomy and tumorectomy in the right kidney were performed. Solitary metastasis to the pancreas without symptoms was treated by distal pancreatectomy with tumor and splenectomy. Although bilateral renal cell carcinomas were histologically renal cell carcinoma (clear cell subtype, grade 2), the resected pancreatic tumor was renal cell carcinoma with sarcomatoid change. Therefore, the metastatic tumor had a more malignant potential than the primary tumor. The pancreatic metastasis was seen at 6 years 10 months and 2 years 6 months after left nephrectomy and enucleation of the right renal tumors, respectively. The patient is alive without disease and is being treated by alpha-interferon for 12 months after distal pancreatectomy. A careful long-term follow-up of the patient with renal cell carcinoma seems to be necessary.     

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.     

Parenchymal sparing surgery in patients with hereditary renal cell carcinoma: 10-year experience

PURPOSE: von Hippel-Lindau disease, hereditary papillary renal cell carcinoma, the Birt-Hogg-Dubé syndrome and familial renal oncocytoma are familial renal tumor syndromes. These hereditary disorders are noteworthy for the development of multiple bilateral renal tumors and the risk of new tumors throughout life. One management strategy is observation of solid renal tumors until reaching 3 cm, then performing parenchymal sparing surgery. We present a 5-year update on our experience. MATERIALS AND METHODS: From May 1988 to October 1998, 49 patients with hereditary renal cell carcinoma, including von Hippel-Lindau disease in 44, hereditary papillary renal cell carcinoma in 4 and the Birt-Hogg-Dubé syndrome in 1, and 1 with familial renal oncocytoma underwent exploration to attempt renal parenchymal sparing surgery. Patients were followed prospectively with periodic screening for recurrence, metastasis and loss of renal function. Median followup was 79.5 months (range 0.7 to 205). RESULTS: A total of 50 patients underwent 71 operations resulting in unilateral nephrectomy in 6, bilateral nephrectomy in 1 and partial nephrectomy in 65, with 1 to 51 tumors removed from each kidney (mean 14.7). Mean patient age was 39.5 years (range 18 to 70). Of the 65 (40%) partial nephrectomies 26 were performed with cold renal ischemia. Mean blood loss was 2.9 +/- 0.5 l (range 0.15 to 23). Postoperative complications included renal atrophy in 3 patients. Mean preoperative serum creatinine was 1.05 +/- 0.03 mg/dl (range 0.6 to 1.8), and postoperative creatinine was 1.06 +/- 0.04 mg/dl (range 0.6 to 2.0). No patient who underwent renal parenchymal sparing surgery required renal replacement therapy. Metastatic disease developed in 1 patient with a 4.5 cm renal tumor. CONCLUSIONS: Parenchymal sparing surgery with a 3 cm threshold in patients with hereditary renal cancer appears to be an effective therapeutic option to maximize renal function while minimizing the risk of metastatic disease.