Unusual presentation of bilateral adrenocortical carcinoma mimicking adrenal metastasis.

A 75-year-old female visited our hospital with bilateral adrenal masses that were detected incidentally during lumbar spine magnetic resonance imaging (MRI) for the evaluation of radiating flank pain. Consecutive computed tomography and MRI revealed bilateral adrenal masses with no evidence of lymph node enlargement or local invasion; 2[(18)F]fluoro-2-deoxyglucose (FDG)-positron emission tomography showed an intense FDG accumulation in both adrenal glands without abnormal FDG uptake in extra-adrenal regions. The laboratory test results were within normal ranges. We performed a bilateral adrenalectomy. The pathologic diagnosis of both adrenal masses was consistent with adrenocortical carcinoma. The patient recovered well with no complications.