Bilateral adrenal tumor: causes and clinical features in eighteen cases.

Bilateral adrenal neoplasms are very rare. Studies have shown that most are metastatic tumors, and clinical presentation varies with tumor type. We retrospectively reviewed medical records of 18 cases of bilateral adrenal tumor in our hospital between 2002 and 2007. The etiology was pheochromocytoma in six, primary lymphoma in four, nonfunctioning cortical adenoma in four, metastatic tumors in two, primary aldosteronism in one, and Cushing syndrome in one. Patients with lymphoma had largest average tumor size. Our findings suggest that pheochromocytoma, primary lymphoma, and nonfunctioning cortical adenoma are common causes of bilateral adrenal tumor.