Squamous cell carcinoma at the prostatectomy site: squamous differentiation of recurrent prostate carcinoma.

Adenosquamous carcinoma of the prostate is rare. Even rarer is the subsequent squamous metastasis or recurrence in which only the malignant squamous component is observed in some sites, with the adenocarcinoma present in other sites. We describe a case of squamous cell carcinoma presenting at the prostatic bed 6 years after radical retropubic prostatectomy was performed for adenocarcinoma. Even though the primary tumor showed adenocarcinoma with foci of squamous differentiation, there was no morphologic evidence of adenocarcinoma in the current tissue examined. The suspected origin of the squamous tumor from a recurrence of the prostate tumor is discussed.