Squamous cell carcinoma arising from a seminal vesicular cyst: possible relationship between chronic inflammation and tumor development.

A case of squamous cell carcinoma arising within an acquired seminal vesicular cyst is described. A 61-year-old man was hospitalized because of hemospermia and dysuria. Under the diagnosis of a left seminal vesicular cyst, surgical resection was performed. Pathological examination revealed squamous cell carcinoma within a seminal vesicular cyst, along with squamous metaplastic foci and severe chronic inflammation. Cell proliferation, determined with reference to MIB-1 labeling indices, showed a stepwise increase from normal columnar epithelium, through squamous metaplasia, to squamous cell carcinoma. Sporadic p53 protein accumulation without evident gene mutations was also apparent in both the carcinoma and squamous metaplastic lesions. We therefore concluded that the squamous cell carcinoma might have developed from squamous metaplastic foci associated with chronic inflammatory stimulation, within a seminal vesicular cyst.