Surgical treatment of adrenal metastasis from renal cell carcinoma: a single-centre experience of 45 patients.

OBJECTIVE: To report, in a retrospective study, the diagnostic problems and oncological results of surgery in patients with either synchronous or metachronous adrenal metastasis, which are uncommon in renal cancer, at 2-10% of patients.

PATIENTS AND METHODS: Of 1179 patients treated for renal cancer between 1987 and 2003, 914 had renal surgery with concomitant ipsilateral adrenalectomy (routinely in 875 and for abnormal findings on computed tomography, CT, in 39) and 15 contralateral adrenalectomy (all after suspicious findings on CT). During the follow-up after renal surgery, another 14 patients had adrenalectomy for CT evidence of an abnormal adrenal gland, contralateral to the previous renal tumour in 12 and bilaterally in two.

RESULTS: Of 914 ipsilateral adrenal glands removed during renal surgery, 854 (93.5%) were normal on pathological examination, 28 (3%) had a benign pathology, six (0.8%) were directly infiltrated by the tumour and 26 (2.7%) were metastatic. For both benign and metastatic ipsilateral adrenal pathology, CT had sensitivity, specificity and positive/negative predictive values of 47%, 99%, 73% and 96%, respectively. Of 29 contralateral glands removed because of suspicious CT findings (15 at diagnosis of renal cancer, 14 during the follow-up) there was no abnormality in one (3.4%), a benign pathology in seven (24%) and a metastasis in 21 (72%). Thus there were 32 synchronous (incidence 2.7%; ipsilateral to the renal tumour in 24, contralateral in six and bilateral in two), and 13 metachronous adrenal metastases (incidence 1.0%; contralateral in 11 and bilateral in two). The metachronous metastases were diagnosed at a mean (range) interval of 30.6 (8-73) months after renal surgery. No ipsilateral adrenal metastases were discovered at diagnosis or during the follow-up in the 382 patients with an organ-confined renal tumour of <4 cm in diameter. Twenty-seven patients with an isolated adrenal metastasis (synchronous in 14, metachronous in 13) had statistically significantly (P < 0.001) better survival than the 18 (all synchronous) with multiple sites of metastatic disease. In particular, there was long-term survival (mean 83 months) in 10 patients with an isolated adrenal metastasis.

CONCLUSION: Sparing the ipsilateral adrenal is advisable only for organ-confined renal tumours of <4 cm in diameter; clinical local staging of renal cancer is the best predictor of the risk of adrenal metastasis. Conversely, CT had good diagnostic ability for the contralateral adrenal gland, especially during the follow-up. Some patients with isolated adrenal metastasis could be treated by metastasectomy, with long-term survival free of disease and confirming that, even if in a few and unselectable patients, removing all the neoplastic bulk can be curative. Nevertheless, the high rate of relapse underlines the need for an effective systemic therapy, and more so for widespread metastatic disease that currently cannot be cured.