Abstract
Introduction: Renal cell cancer (RCC) represents the fifth most common cancer in men, with a rising
incidence. Computerized tomography (CT) remains the most appropriate imaging modality to diagnose renal
malignancies. Preoperative CT imaging provides to differentiate benign from malignant lesions, to assess
tumor size, tumor localization, tumor number, to identify lymph node and/or distant metastasis, adrenal gland
involvement, and to predict the presence of thrombus of the vena cava. Tumor number and the adrenal gland
involvement are the most important factors for surgical planning. In this regard, reliable radiographic
guidelines to assess the tumor number and the adrenal gland involvement preoperatively allow the surgeon to
select patients for partial nephrectomy or adrenal sparing procedures. In this study we examined preoperative
abdominal CT findings for tumor number and adrenal gland involvement. Subsequently these findings were
compared to histopathological results to determine the accuracy of CT in the diagnosis of tumor number and
adrenal involvement as well as establish parameters to ensure further accurate diagnosis.
Materials and Methods: We investigated 198 patients with RCC who were treated with radical
nephrectomy and ipsilateral adrenalectomy at five different medical centers from 2000 to 2004 retrospectively.
The mean age in the patients was 57.3 (15-86) years. Eighty-two of the patients were female, 116 were male.
Mean ages of the male and female patients were 58.1 and 57.7 years, respectively. Renal masses diagnosed with
contrast enhanced abdominal CT imaging. Also, tumor localization, tumor number, lymph node and adrenal
gland involvement were assessed preoperatively. All the patients underwent radical nephrectomy and
ipsilateral adrenalectomy. We assessed the accuracy of preoperative abdominal CT findings for identifying
tumor number and adrenal gland involvement compared with postoperative histopathological results.
Results: Mean tumor size was 8.0±3.6 (2-23) cm. At the end of the histopathological examination, Stage 1,
2, 3, and 4 tumors were detected in 72 (36.4%), 74 (37.4%), 49 (24.7%) and 3 (1.5%) patients, respectively.
Adrenal gland involvement was detected in 13 patients (6.5%) with histopathological examination. While
preoperative CT demonstrated adrenal gland involvement in 7 patients, histopathology reports confirmed only
in 4 patients. CT demonstrated a sensitivity of 30.8%, specificity of 98.4%, positive predictive value of 57.1%,
and negative predictive value of 95.2% for adrenal gland involvement. There was no significant difference
between upper pole tumors and other regions tumor with regard to adrenal gland involvement. While CT was
demonstrated unifocal tumor in 188 patients, histopathology reports were detected in 180 patients. CT
demonstrated a sensitivity of 20%, specificity 95.7%, positive predictive value of 20%, and negative predictive
value of 95.7% for detecting tumor multifocality.
Conclusion: In the light of our results, preoperative abnormal CT findings are less reliable for detecting
tumor multifocality and adrenal gland involvement. According to histopathological examination, preoperative
CT findings missed adrenal gland involvement and multifocal tumor in 4.7% and 4.3% of the patients.
Although, CT is more reliable diagnostic method for adrenal gland involvement and tumor multifocality,
either sophisticated radiological techniques or specific marker should be needed.