Adenosquamous Carcinoma of the Prostate: A Unique Presentation of a Rare Entity and Review of the Literature

Adenosquamous carcinoma of the prostate is an exceedingly rare and aggressive histologic variant of prostate cancer, which is composed of glandular and squamous components. Up to two-thirds of these cases are identified in patients with a history of adenocarcinoma after treatment with androgen deprivation therapy or radiation therapy; however, multiple cases have been reported arising de novo. Patients frequently present with obstructive urinary complaints and bony osteolytic metastases. Serum prostate-specific antigen is usually normal or slightly elevated. We describe a rare case of de novo metastatic adenosquamous carcinoma in a patient presenting with a markedly elevated serum prostate-specific antigen and multiple osteoblastic lesions. The prognosis for patients with adenosquamous carcinoma of the prostate has historically been dismal, with death occurring within 12 to 24 months of diagnosis.