Vol. 118, November Printed in U.SA.
THE JOURNAL OF UROLOGY
Copyright © 1977 by The Williams & Wilkins Co.
RENAL ONCOCYTOMA: A RARE CASE OF RENAL ADENOMA M. MILSTOC From the New York University Medical Center, Goldwater Memorial Hospital, F. D. Roosevelt Island, New York
ABSTRACT
A case of renal oncocytoma is reported. The important pathologic aspects of this rare, asymptomatic, large benign neoplasm are described. Oncocytoma is the name given by Jaffe 1 as a synonym for adenolymphomas of the salivary glands but Hamperl2 insisted that the term should apply only to those adenomas that are entirely composed of oncocytes. Since the oncocytic cells were found not only in the salivary glands, oncocytomas were described in many other organs. 3 A review of the literature by Klein and Valensi during a clinicopathologic study on kidney oncocytomas revealed that only 20 such cases had been documented, 13 of which they identified. 4 From their discussion it appears that in some cases this benign neoplasm was unrecognized and labeled as carcinoma. Therefore, it is not only necessary to review the pathology files in order to identify cases of oncocytoma retroactively but new cases should be reported to alert the clinicians and pathologists of its increasing incidence so that it will be considered in their diagnosis.
oncocytes as described by Hamperl, that is altered oxyphilic epithelial cells with the cytoplasmic volume exceeding that of their cells of origin and containing small, uniformly hyperchromic nuclei. Owing to the lack of experience and statistical evaluation the presence of this tumor in the kidney was
CASE REPORT
A 93-year-old white man was hospitalized on January 8, 1968 for rehabilitation and chronic care because ofhemiparesis on the left side after a cerebral artery thrombosis. He remained stable until December 1976, when congestive heart failure and renal failure occurred. Temperature ranged from 101 to 103F. The white blood count was 31,200, blood urea nitrogen (BUN) 83 mg. and creatinine 4.2 mg. The urine was normal. The patient improved gradually with the white blood count reaching 12,600, BUN 40 and creatinine 1.8 mg. but he became progressively weaker. On May 1, 1977 he died. An autopsy revealed pulmonary emphysema, diffuse bronchopneumonia and edema; generalized arteriosclerosis with calcific coronary arteries, mitral and aortic valves, cholelithiasis and chronic passive congestion of the.liver. The kidneys showed arterionephrosclerosis and arteriolar nephrosclerosis. The lower pole of the left kidney demonstrated an unsuspected subcapsular soft bluish red mass, measuring 5 cm. in diameter. The cut section revealed a well circumscribed, partially encapsulated, hemorrhagic, variegated, soft, reddish tumor extending into the parenchyma (fig. 1). There was no infiltration of the tumor beyond the capsule, no lymph nodes, no renal vein involvement and no necrosis. The microscopic examination revealed a mass of polygonal epithelial cells that contained mostly homogeneous abundant eosinophilic cytoplasm with uniform small, pyknotic nuclei. These cells were arranged in a tubular pattern and were often disturbed by marked hemorrhage (fig. 2). DISCUSSION
Large kidney adenomas have been reported in the medical literature but most of them are described as having basophilic cells arranged in tubular or papillary structures. 5 The tumor cells found in this case have all the characteristic features of Accepted for publication July 15, 1977.
856
Fm. 1. Well circumscribed oncocytoma oflower pole of kidney
either missed or challenged but there is no reason why an oncocyte cannot develop in the kidney as it does in many other organs. Unlike the malignant neoplastic cells those found in this case show no clear cells or a mixture of clear cells and granular cells, no mixture of basophilic and eosinophilic cytoplasms, no polymorphic nuclei, no mitosis and no necrosis. The slides also were examined by a group of pathologists at the New York University Medical Center and at Bellevue Hospital and they concurred with the diagnosis of oncocytoma. Ultrastructurally, these cells were shown to have
857
RENAL ONCOCYTOMA
an abundance of mitochondria, thus explaining the fact some authors call the tumor mitochondrioma. 6 The size of the tumor has no relation to its behavior and the presence of hemorrhage, which was rarely mentioned in other cases, is probably owing to the congestive heart failure in this case. The tumor often is associated with nephrosclero·· sis, which this patient had, and is related to changes in the proximal tubules. For this reason it was suggested differentiate renal oncocytoma from the oncocytic neoplasms in other organs, those of the kidney be called proximal tubular adenoma with oncocytic features. 4 The tumor shows an increased incidence in elderly and cachectic patients. The age range in the series described by Klein and V alensi ,was between 51 and 80 years. This patient was cachectic and appears to be the oldest one reported. Generally, male :ow"J"'-''"" are predominant and most of those cases reported were this area. At this stage the significance of all of these miological factors cannot yet be evaluated. REFERENCES
1. Jaffe, R. H.: Adenolymphoma (onkocytoma) of parotid Amer. J. Cancer, 16: 1415, 1932. 2. Hamperl, H.: Benign and malignant oncocytoma. Cancer,
Fm. 2. Renal oncocytic cells arranged in tubular pattern
1019, 1962. 3. Hamper!, H.: Oncocytoma of different organs. Acta Union Int. Cancer, 20: 854, 1962. 4. Klein, M. J. and Valensi, Q. J.: Proximal tubular adenomas of kidney with so-called oncocytic features. Cancer, 38: 906, 1976. 5. Ellner, H. J., Bergman, H. and Alfonso, G.: Two cases solitary giant tubular adenoma of the kidney simulating carcinoma of the renal parenchyma. J. UroL, 84: 706, 1960. 6. Sun, C. N., White, H. J. and Thompson, B. W.: Oncocytoma (mitochondrioma) of the parotid gland- an electron microscopic study. Arch. Path., 99: 208, 1975.
THE JOURNAL OF UROLOGY
Copyright © 1977 by The Williams & Wilkins Co.
RENAL ONCOCYTOMA: A RARE CASE OF RENAL ADENOMA M. MILSTOC From the New York University Medical Center, Goldwater Memorial Hospital, F. D. Roosevelt Island, New York
ABSTRACT
A case of renal oncocytoma is reported. The important pathologic aspects of this rare, asymptomatic, large benign neoplasm are described. Oncocytoma is the name given by Jaffe 1 as a synonym for adenolymphomas of the salivary glands but Hamperl2 insisted that the term should apply only to those adenomas that are entirely composed of oncocytes. Since the oncocytic cells were found not only in the salivary glands, oncocytomas were described in many other organs. 3 A review of the literature by Klein and Valensi during a clinicopathologic study on kidney oncocytomas revealed that only 20 such cases had been documented, 13 of which they identified. 4 From their discussion it appears that in some cases this benign neoplasm was unrecognized and labeled as carcinoma. Therefore, it is not only necessary to review the pathology files in order to identify cases of oncocytoma retroactively but new cases should be reported to alert the clinicians and pathologists of its increasing incidence so that it will be considered in their diagnosis.
oncocytes as described by Hamperl, that is altered oxyphilic epithelial cells with the cytoplasmic volume exceeding that of their cells of origin and containing small, uniformly hyperchromic nuclei. Owing to the lack of experience and statistical evaluation the presence of this tumor in the kidney was
CASE REPORT
A 93-year-old white man was hospitalized on January 8, 1968 for rehabilitation and chronic care because ofhemiparesis on the left side after a cerebral artery thrombosis. He remained stable until December 1976, when congestive heart failure and renal failure occurred. Temperature ranged from 101 to 103F. The white blood count was 31,200, blood urea nitrogen (BUN) 83 mg. and creatinine 4.2 mg. The urine was normal. The patient improved gradually with the white blood count reaching 12,600, BUN 40 and creatinine 1.8 mg. but he became progressively weaker. On May 1, 1977 he died. An autopsy revealed pulmonary emphysema, diffuse bronchopneumonia and edema; generalized arteriosclerosis with calcific coronary arteries, mitral and aortic valves, cholelithiasis and chronic passive congestion of the.liver. The kidneys showed arterionephrosclerosis and arteriolar nephrosclerosis. The lower pole of the left kidney demonstrated an unsuspected subcapsular soft bluish red mass, measuring 5 cm. in diameter. The cut section revealed a well circumscribed, partially encapsulated, hemorrhagic, variegated, soft, reddish tumor extending into the parenchyma (fig. 1). There was no infiltration of the tumor beyond the capsule, no lymph nodes, no renal vein involvement and no necrosis. The microscopic examination revealed a mass of polygonal epithelial cells that contained mostly homogeneous abundant eosinophilic cytoplasm with uniform small, pyknotic nuclei. These cells were arranged in a tubular pattern and were often disturbed by marked hemorrhage (fig. 2). DISCUSSION
Large kidney adenomas have been reported in the medical literature but most of them are described as having basophilic cells arranged in tubular or papillary structures. 5 The tumor cells found in this case have all the characteristic features of Accepted for publication July 15, 1977.
856
Fm. 1. Well circumscribed oncocytoma oflower pole of kidney
either missed or challenged but there is no reason why an oncocyte cannot develop in the kidney as it does in many other organs. Unlike the malignant neoplastic cells those found in this case show no clear cells or a mixture of clear cells and granular cells, no mixture of basophilic and eosinophilic cytoplasms, no polymorphic nuclei, no mitosis and no necrosis. The slides also were examined by a group of pathologists at the New York University Medical Center and at Bellevue Hospital and they concurred with the diagnosis of oncocytoma. Ultrastructurally, these cells were shown to have
857
RENAL ONCOCYTOMA
an abundance of mitochondria, thus explaining the fact some authors call the tumor mitochondrioma. 6 The size of the tumor has no relation to its behavior and the presence of hemorrhage, which was rarely mentioned in other cases, is probably owing to the congestive heart failure in this case. The tumor often is associated with nephrosclero·· sis, which this patient had, and is related to changes in the proximal tubules. For this reason it was suggested differentiate renal oncocytoma from the oncocytic neoplasms in other organs, those of the kidney be called proximal tubular adenoma with oncocytic features. 4 The tumor shows an increased incidence in elderly and cachectic patients. The age range in the series described by Klein and V alensi ,was between 51 and 80 years. This patient was cachectic and appears to be the oldest one reported. Generally, male :ow"J"'-''"" are predominant and most of those cases reported were this area. At this stage the significance of all of these miological factors cannot yet be evaluated. REFERENCES
1. Jaffe, R. H.: Adenolymphoma (onkocytoma) of parotid Amer. J. Cancer, 16: 1415, 1932. 2. Hamperl, H.: Benign and malignant oncocytoma. Cancer,
Fm. 2. Renal oncocytic cells arranged in tubular pattern
1019, 1962. 3. Hamper!, H.: Oncocytoma of different organs. Acta Union Int. Cancer, 20: 854, 1962. 4. Klein, M. J. and Valensi, Q. J.: Proximal tubular adenomas of kidney with so-called oncocytic features. Cancer, 38: 906, 1976. 5. Ellner, H. J., Bergman, H. and Alfonso, G.: Two cases solitary giant tubular adenoma of the kidney simulating carcinoma of the renal parenchyma. J. UroL, 84: 706, 1960. 6. Sun, C. N., White, H. J. and Thompson, B. W.: Oncocytoma (mitochondrioma) of the parotid gland- an electron microscopic study. Arch. Path., 99: 208, 1975.
