Hi Venhum and Welcome to the Forum! This tumor is indeed very rare. The literature seems to be almost entirely case reports, however, this one also has a review:
Prostatic stromal sarcoma. A case report and literature review (2018, Full Text)
The young patient in this case report underwent a prostatectomy. Depending on the general health of your husband, I would think surgery is not out of the question at age 80. Studies on RP in the elderly seem to emphasize that general health is more important than chronological age.
If you want more information, see the Reference section in the above paper. For more information, you can search "Prostatic stromal sarcoma" at
pubmed and
google scholarKeep us posted please.
Best wishes!
Djin