A 62-year-old man presented with a rising serum concentration of
prostate-specific antigen (PSA) to 53.3 ng/mL (to convert to μg/L, multiply by 1) and a PSA doubling time of 2.6 months. Computed tomography, fluorodeoxyglucose-positron emission tomography, and C-11
choline positron emission tomography demonstrated a parotid mass with innumerable lytic bone lesions and diffuse metastatic disease to the neck and mediastinal lymph nodes. Mediastinal lymph node biopsy revealed salivary ductal
adenocarcinoma that produced PSA and demonstrated
androgen receptor sensitivity. The patient had a prolonged clinical benefit to first- and second-line
hormone therapy, and his PSA levels correlated with treatment response, development of
hormone resistance, and progression. In summary, urologists, pathologists, and primary care providers should be aware that a rising PSA level in the setting of a head and neck mass in a patient without a history of
prostate cancer does not constitute a diagnosis of metastatic prostate
adenocarcinoma and that other primary
tumors should be considered and a broader imaging and pathologic evaluation is indicated.