Objective: Prostatic tumors are the most frequent malignant neoplasms in men, most of them being constituted by carcinomas; only 0.2% of malignant prostatic neoplasms are of mesenchimal origin. They are not well known, especially those of prostatic stromal phenotype.
Methods and results: We report the case of a 20 year-old man with a prostatic stromal sarcoma. After total cystoprostatectomy a tumor measuring 8 cm could be seen, replacing almost the whole prostate. Microscopically a spindle cell neoplasia with moderate atypia and a high mitotic index entrapping few elongated prostatic ducts (adopting a phyllodes tumor morphology) was observed.
Conclusion: The clinical behavior of these infrequent sarcomas is not well-established. Recurrences are not uncommon whereas lung and bone metastases have been described. Twelve months after surgery our patient is alive without evidence of disease.