Atypical ductal adenocarcinoma of the prostate with endometrioid immunohistological features

We present the case of a 52-year-old Caucasian male, admitted to our institution for a verumontanum adenocarcinoma, partially resected endoscopically, a month earlier at another urological clinic. The prior pathological examination wasn't able to give diagnosis. The extensive assessment by clinical workup, ultrasound, flexible cystoscopy, CT scan, and MRI revealed a prostatic tumor extending from the verumontanum to the left lobe and seminal vesicle. The patient underwent radical prostatectomy. The pathological examination revealed a ductal like adenocarcinoma, positive on immunohistochemistry for pan cytokeratin (AE1/AE3), CD10, endomysial antibody EMA and progesterone receptors (PR) and negative for prostate specific antibody (PSA), prostatic specific acid phosphatase (PSAP) and androgen receptors (AR). Ductal like adenocarcinoma of the prostate with endometrioid immunohistological features in the absence of prostate markers is an unusual condition.