Clinicopathological conference: incidentally found renal mass

Doctor Petersen confirmed our preoperative suspicion that this lesion might represent a benign proximal tubular adenoma. Tessler and associates found 5 such cases from July 1974 to January 1975 and reviewed all cases of renal carcinoma in their institution from 1952 through 1975. An additional 9 cases were discovered with none before 1964. One must ask if there is an increased incidence now occurring or are we just beginning to recognize this entity with increasing sophistication? The question also must arise whether with a high degree of suspicion a less radical operation is indicated. Certainly, the angiogram is the only possible preoperative tool that can arouse suspicion but this still is far from diagnostic. The spoke-wheel configuration of vessels, a homogeneous nephrogram similar to the normal parenchyma and sharp margination in the absence of marked increased vascular puddling may all be suggestive. In this older patient with a normal contralateral kidney total nephrectomy still is indicated because angiographic patterns are not pathognomonic. Conversely, in the rare younger individual with concomitant unrelated bilateral renal disease or in the solitary kidney with a polar lesion partial nephrectomy should be considered. Although some differential recognition may be possible by gross examination, such as the tan color, sharp demarcation, absence of hemorrhage or necrosis and so forth, it always has been our policy not to violate Gerota's fascia or to biopsy in the treatment of suspected renal carcinoma. Thus, until a specific preoperative diagnosis is possible nephrectomy continues to be the treatment of choice in the proximal tubular adenoma with so-called oncocytic features. Debate will continue in urologic, pathologic and radiologic circles on whether such an entity is universally benign and with increasing recognition only time will tell.