Fine needle aspiration of metastatic prostate carcinoma simulating a primary adrenal cortical neoplasm: a case report and review of the literature.

Adrenal metastases usually occur in prostate cancer patients with widespread bone and visceral disease. Autopsy studies have shown that adrenal metastases may be found in up to 23% of these patients. However, the finding of an isolated adrenal metastasis without the involvement of other organs in a patient with prostate cancer is exceedingly rare. Thus, it may cause a diagnostic dilemma on FNA cytology. We report a patient with a history of prostate cancer, status post radiation, and hormonal therapy 4 years before, who presented with a new, single adrenal mass on abdominal imaging studies. The ultrasound-guided FNA cytology of the adrenal mass revealed cytomorphological features that were suggestive of a primary adrenal cortical neoplasm, but overlapped with those of a prostate metastasis. To our knowledge, FNA findings of metastatic prostate cancer simulating an adrenal cortical neoplasm have not been previously reported in the English literature. The purpose of our study is to discuss the differential diagnosis of these entities. The accurate diagnosis is important because of different prognosis and treatment implications for the various diseases.