Contralateral adrenal metastasis in renal cell cancer

A 60-year-old female patient presenting with anemia was found to have a left-sided renal tumor and a contralateral adrenal mass of 2 cm in diameter. Imaging studies for metastases were negative. Nephrectomy along with contralateral adrenalectomy was performed and histology disclosed renal cell carcinoma stage pT3a pNO G2 with solitary contralateral adrenal metastasis. In a survey of the literature, 24 previous cases of renal cancer with solitary contralateral adrenal metastasis were identified. The most probable biological pathway to explain this peculiar metastatic pattern is transpulmonal passage of circulating cancer cells and seeding in the adrenal gland on the basis of a particular susceptibility of adrenal tissue to circulating renal cancer cells. The case illustrates that surgery of solitary metastases from renal cell carcinoma may be beneficial to the patient. The case further highlights the caution that is required diagnostically in the interpretation of incidentally found adrenal masses when other malignancies are present.