How would you approach low grade non-invasive urothelial carcinoma arising from seminal vesicle and ejaculatory ducts with invasion into prostate?

Primary urothelial carcinoma of seminal vesicle is extremely rare. There is some skepticism whether this is a true entity. More common is the secondary spread from bladder primary. This can happen as a result of direct invasion through bladder wall or via mucosal spread. Formal is staged as T4 disease and should be managed as such because of poor prognosis of this subset (Daneshmand et al., PMID 15201742, You et al., PMID 20608931).

Mucosal spread is rare, less recognized, and less understood. There were reports of CIS of bladder or prostatic urethra that spread in this fashion (Montie et al., PMID 9334625, Ro et al., PMID 3688301). This was a plausible explanation in this case given the continuum of spread to seminal vesicle, ejaculatory du...