Errors in Angiographic Diagnosis of Renal Masses

Abstract

THE PLACE of renal arteriography in theT diagnosis and management of patients with suspected renal masses has been the subject of controversy since dos Santos introduced translumbar aortography in 1929 (1). Errors were made, however, in differentiating renal cysts from neoplasms (2–4). The kidney might be overlapped by extrarenal arteries, and the contrast medium diluted to such an extent as to limit vascular details. Many physicians believed that all patients with urographic evidence suggesting neoplasm should undergo surgical exploration and that renal angiography was unnecessary. The advent of the selective technic of renal angiography prompted a reappraisal of the role of arteriography in the diagnosis of renal lesions. As experience with this new method increased, however, it became evident that the angiographic appearances of renal adenomas, hamartomas, and inflammatory processes might be confused with those of cysts and malignant tumors, and that renal-cell carcinoma might be mistakenly diagnosed as a benign lesion. Despite its limitations, selective renal angiography has been performed since 1964 in the Cleveland Clinic Hospital in all cases of suspected renal mass. In addition to the obvious advantage of providing additional diagnostic information when urographic studies were positive, its potential was considered useful in the management of the patient with equivocal evidence of a renal mass or with hematuria without urographic abnormality. In addition, if the surgeon undertook transperitoneal nephrectomy rather than flank surgery in renal-cell carcinoma, he required accurate preoperative diagnosis. The initial experience was rewarding, but with a steadily increasing number of patients studied, diagnostic errors were encountered. In case of benign disease diagnosed as malignant, the consequences in the treatment of the patients were not important. Ifsurgery were not performed in malignant disease, however, serious mistakes in management might have been made. This communication presents our experience with erroneous angiographic diagnoses in an unselected group of 497 patients studied because of renal masses. Emphasis is placed upon 10 cases of malignant tumors that were incorrectly diagnosed. Material And Methods Abdominal aortography in the anteroposterior projection and selective renal arteriography in anteroposterior and postero-oblique projections were performed in all cases. The films were exposed at a minimum rate of 3 per second for the first second, 2 per second for the next four seconds, and 1 per second for the final five seconds. All radiographs were considered to be of good technical quality. Surgical exploration and either nephrectomy or biopsy were performed in all but 4 of the patients in whom the angiographic findings were positive.