Adrenal Tumors Identified on Abdominal Imaging in Breast Cancer Patients: Benign Incidentalomas or Metastatic Disease?

INTRODUCTION: Adrenal incidentalomas are usually benign nonfunctional adrenal adenomas when found in noncancer patients. However, adrenal incidentalomas may represent metastatic disease in patients with a history of breast cancer. For managing clinicians, the distinction between benign incidentalomas and metastatic disease is important as metastases may require a percutaneous biopsy and a change in management, while most adenomas do not require intervention. This study investigates whether radiographic and clinical features can distinguish benign adrenal tumors from adrenal metastases in breast cancer patients. METHODS: We performed a single institution review of 2745 breast cancer patients with abdominal imaging. Adrenal tumors were classified as benign, metastatic, or indeterminate based on predetermined radiologic criteria. Statistical analysis was performed to identify factors associated with metastases. RESULTS: A total of 103 (3.8%) breast cancer patients had adrenal tumors: 79 (77%) benign, 11 (11%) metastatic, and 13 (13%) indeterminate. Adrenal metastases had a larger initial mean tumor size (2.4 versus 1.7 cm, P = 0.03) and were more likely to have additional sites of metastases identified on the same scan (64% versus 24%, P = 0.01) than benign tumors. Multivariate analysis showed that the presence of other metastases (odds ratio [OR] 7.73, P = 0.01), larger initial tumor size (OR 1.90, P = 0.048), and finding an adrenal tumor on a surveillance scan (OR 8.60, P < 0.01) increased the likelihood of the lesion being metastatic disease. CONCLUSIONS: Most adrenal tumors found on abdominal imaging for breast cancer patients are benign, but larger adrenal tumors and patients with other sites of metastasis are at increased risk for adrenal metastases.