Bilateral renal oncocytoma: report of 2 cases and literature review

Multiple Tumor Case: Report and Analysis of an Autopsy Case

An interesting multiple tumor case is described in which 4 different kinds of tumors were diagnosed in the same patient at autopsy and histopathologic examination. The tumors were the following: 1) prolactinoma of the anterior pituitary lobe; 2) basal cell carcinoma of the nose; 3) adenocarcinoma of the colon sigmoideum; 4) multiple oncocytomas (oncocytomatosis) in the kidneys. Immunohistochemical investigation for p53 revealed a strong intranuclear positivity in the colonic carcinoma cells as a result of the overexpression of a possible mutant type of the protein. The other 3 tumors were negative with the p53-specific DO-7 antibody, therefore, no point mutation was thought to be present in the p53 gene of the tumor cells. The immunohistochemical and anamnestic data suggested that this is not a hereditary syndrome, and there is no common pathogenesis of these tumors. Its rarity is interesting in our case because of the coincidence of 4 different unrelated tumors and the absence of anamnestic data for familial accumulation or predisposition for multiple tumors.

Common and uncommon adult unilateral renal masses other than renal cell carcinoma

Many different masses can involve the kidney other than the commonly encountered renal cell carcinoma (RCC). The purpose of this article is to review the characteristic clinical and imaging findings of common and uncommon masses that predominantly present unilaterally in the adult patient, other than RCC. Awareness of such lesions and knowing the clinical scenario is important for appropriate diagnosis and management, especially in a multidisciplinary care setting.

Molecular pathology of renal oncocytoma: a review

Differentiating renal oncocytoma from its renal cell carcinoma (RCC) mimics, particularly chromophobe RCC, can be difficult, especially when limited tissue is available for evaluation and requires sophisticated microscopic, ultrastructural and immunohistochemical evaluation. In this review, the relevant literature has been reviewed, and supporting data obtained by applying modern microarray-based technologies are discussed with a focus on molecular pathology of renal oncocytoma. The high resolution whole-genome DNA-microarray based analyses excluded with all certainty the occurrence of small specific alterations. Renal oncocytomas are characterized by variable chromosomal patterns. The number of genes selected by global gene expression analyses and their usefulness in the diagnostic pathology based on immunohistochemical evaluation is far below the expectations. The conflicting staining patterns, together with the poor specificity of proposed antibodies, leads us to believe that these candidate immunomarkers might not help in the separation of these tumors. Applying DNA based tools might help in the diagnosis of renal oncocytoma with uncertain histology. However, only the combination of all available techniques could give reliable information.

Sonography in Benign and Malignant Renal Masses

Ultrasonography and CT have allowed improved detection of renal mass lesions. Though ultrasonography is less sensitive in the characterization of the renal mass lesions, it is often the first imaging modality for evacuation of the kidneys. This article gives an overview of the benign and malignant renal mass lesions and the role of ultrasonography in their characterization.

Adénome oncocytaire du rein : redéfinition des critères diagnostiques en tomodensitométrie

PURPOSE

To redefine and evaluate the computed tomographic criteria for the diagnosis of renal oncocytoma (RO) for which renal sparing surgery should be preferred.

MATERIAL AND METHOD

Retrospective study of 57 patients with 69 RO. Macroscopic and histological correlation was obtained in all cases. A double blinded comparative study was made of 60 renal tumors (containing adenocarcinomas and oncocytomas) larger than 3 cm in diameter in order to evaluate the redefined CT diagnostic criteria.

RESULTS

Among RO larger than 3 cm in diameter, 55% presented a sharply defined low attenuation scar on post-contrast scans at the tubular nephrographic phase, central or eccentric, with homogeneous attenuation throughout the remainder of the hypervascular tumor which was classified in 3 different groups. The use of our CT diagnostic criteria gave a statistically significant (p < 0.05) Kappa index of inter-observer concordance of 0.71 and a specificity of 96% for the diagnosis of RO.

CONCLUSION

Our redefined computed tomographic criteria for the diagnosis of renal oncocytoma, eventually associated with renal biopsy, should increase the indications for renal sparing surgery for RO larger than 3 cm in diameter.

Oncocytic renal neoplasms: diagnostic considerations

Advances in our understanding of renal neoplasia have resulted in recognition of numerous tumors that are composed predominantly of cells with abundant eosinophilic cytoplasm. This article discusses the features of renal oncocytoma (including oncocytosis), chromophobe renal cell carcinoma (RCC), and clear cell RCC; explores the relationship between renal oncocytoma and chromophobe RCC; briefly discusses other tumors with abundant eosinophilic cytoplasm; and emphasizes the differential diagnosis of such tumors.

Bilateral multifocal renal oncocytoma--a case report and literature review

A case of bilateral multifocal renal oncocytoma is reported. The incidence, diagnosis and management of such tumors is discussed.

Inherited carcinomas of the kidney

Studies of families with inherited carcinomas have provided powerful tools to identify the genes involved in the pathogenesis of human cancers. In this review, we summarize the clinical, pathological, and genetic characteristics of the inherited carcinomas of the kidney. We emphasize the observation that different genes predispose to histologically different types of renal carcinoma. Hereditary papillary renal carcinoma, a recently described inherited disorder, is discussed in detail along with the predisposing gene, the MET protooncogene. The data support a classification of renal carcinomas based on molecular genetics.

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.

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.

Bilateral renal oncocytomatosis in a patient with renal failure

Bilateral multifocal renal oncocytomas are very rare disorders with only 6 previously reported cases in the world literature, of which only 3 have had pathologic confirmation. We present the first reported case of diffuse, bilateral, multifocal renal oncocytomatosis in a patient with end-stage renal disease requiring hemodialysis. Our patient was found to have hundreds of nodular tumors in both kidneys on exploration, representing the second such reported finding.

Bilateral multifocal renal oncocytoma: case report and review of the literature

We report an unusual case of bilateral multifocal renal oncocytoma. The patient underwent bilateral enucleation of 4 tumors of the right and 4 tumors of the left kidney. Frozen section and permanent pathological diagnosis was renal oncocytoma for all tumors. Only 5 other cases of bilateral multifocal oncocytoma have been reported in the literature, of which only 2 had pathological confirmation of the diagnosis. It is important to recognize the potential for multicentric bilateral oncocytomas and to attempt a renal sparing approach in these cases. However, we performed enucleation of all large lesions due to the documented coexistence of renal oncocytoma and renal cell carcinoma as separate simultaneous lesions.

Ultrasound characteristics of renal cryosurgery

The ability to visualize renal cryosurgery using ultrasound was tested in an animal model. Five dogs underwent open laparotomy and ultrasound-monitored cryosurgery of both kidneys. On each kidney two cryolesions were made. The borders of the frozen region were identified on ultrasound as a hyperechoic rim created by the interface between frozen and unfrozen tissue. The thawed cryolesion appeared hyperechoic compared with the unfrozen kidney. Excellent correlation between the ultrasound and autopsy measurements of the cryolesions was obtained. Knowing this, renal cryosurgery under ultrasound monitoring may be possible.

Bilateral renal oncocytomas: management and nuclear analysis

Only 16 cases of bilateral renal oncocytomas have been previously reported in the English language literature, 9 of which were treated with bilateral surgical resections. We report a case treated with bilateral partial nephrectomy. Although pathological examination revealed grade I oncocytomas on both sides, flow cytometry demonstrated tumor DNA content to be aneuploid on one side and diploid on the other, the first cellular differences reported in a case of bilateral renal oncocytomas. The management of suspected renal oncocytomas is discussed, with emphasis on the need for complete excision in most patients. The results of nuclear studies of these tumors, including DNA flow cytometry, cytogenetics, and molecular analysis of both nuclear and mitochondrial DNA, are reviewed.

Renal oncocytoma: report of a case with bilateral multifocal oncocytomas

Renal oncocytomas are uncommon, benign tumors that classically are treated by local excision or heminephrectomy. Preoperative differentiation from renal cell carcinoma is invaluable in the planning of treatment. Cases of renal oncocytoma treated conservatively have been reported. This is a case report of bilateral multifocal renal oncocytomas of which only three previous cases have been reported. Diagnosis was made from multiple fine needle biopsies and present treatment consists only of conservative observation.

Molecular analysis of the short arm of chromosome 3 in five renal oncocytomas

Renal oncocytomas were tested for loss of alleles at loci on the short arm of chromosome 3, a genetic change characteristic of human renal cell carcinoma. Five renal oncocytomas did not show loss of alleles at loci on 3p supporting the view that renal oncocytoma is a distinct form of renal neoplasia.

Renal oncocytoma: origin from the collecting duct

The histo- and cytogenesis of two cases of renal oncocytoma have been studied by cytomorphological and cytochemical methods. Transitions from collecting ducts into oncocytic tubules were observed at the light and electron microscopic levels. The fine structure of the oncocytes in tubules and tumors is described in detail. Cytochemically, the oncocytic tubules and oncocytomas share many characteristics with the distal nephron, especially the collecting ducts. A striking difference is the enhanced activity of succinic dehydrogenase which corresponds to the increase in the number of mitochondria in oncocytes. All the results suggest that renal oncocytoma originates from the collecting duct.

Unilateral renal oncocytoma: a case report

A case of unilateral renal oncocytoma is reported. Diagnosis, clinical features and management of the tumour are discussed in the light of international literature. The value of angionephrography in the diagnosis of the tumour and in the preoperative planning of surgical therapy is emphasized.

Chromosome anomalies suggestive of malignant transformation in bilateral renal oncocytoma

A patient with bilateral renal oncocytoma is presented, and the clinical, radiological and pathological characteristics of this uncommon, clinically benign renal tumor are discussed briefly. Chromosomal analysis studies revealed the following clonal abnormalities: trisomy of chromosome 7, and monosomy of chromosomes 3 and 14, and the X chromosome. A possible clonal abnormality of chromosome 10 and 3 nonclonal anomalies also were identified. The same anomalies were present in both tumors. These karyotypic anomalies are compatible with malignant transformation of the cells of these tumors and, since benign tumors rarely are associated with demonstrable cytogenetic changes, they suggest that oncocytoma, although clinically benign, may have malignant potential.

Oncocytoma in a horseshoe kidney

Renal oncocytoma is an unusual tumor that has been identified with increasing frequency during the last decade, and more than 150 cases have been reported in the literature, including multifocal and bilateral tumors. We report a case of oncocytoma in a horseshoe kidney. Oncocytoma and tumors in horseshoe kidneys are discussed.

Bilateral kidney tumors: oncocytoma and adenocarcinoma. A case report

An unusual case of bilateral kidney tumors with two histologically different tumors, one right-sided oncocytoma and one left-sided renal cell carcinoma is described. The morphological features of the two tumors are briefly delineated. The diagnostic dilemma between an oncocytoma and a renal cell carcinoma is discussed.