Primary endodermal sinus tumor of the prostate: report of a case.

A 29-year-old man was admitted to the Department of Urology of the University of Padova with a diagnosis of prostatic adenocarcinoma. Cystourethrography showed a prostatic urethral obstruction, and CT scan demonstrated a low pelvic solid mass involving the prostate and the seminal vescicle. A radical prostatectomy was performed, and the prostate was found to be widely infiltrated by a neoplasia formed by tubules, papillary structures, and solid cords of cuboidal or flat elements, each having indistinct borders and scant cytoplasm, in a myxoid or fibrous stroma. "Schiller-Duval-like," PAS-diastase-resistant and alfa-fetoprotein hyaline bodies were present. An endodermal sinus (yolk-sac) tumor was diagnosed. There was infiltration of the periurethral prostatic ducts, prostatic urethra, and seminal vesicles and single lymph node metastasis. Testicular echotomography was negative. In spite of aggressive surgery and chemotherapy, the patient died 10 months after diagnosis. This is the third case in the literature after those presented by Benson and Michel.