Metastasis to the testis from prostatic carcinoma is rare despite the high frequency of carcinoma of prostate and its ability of wide dissemination via 3 mechanisms: local extension, lymphatic metastasis and hematogenous metastasis. According to the autopsy findings most common sites of metastasis of prostate cancer are lung, bladder, liver and adrenal gland metastasis following lymph nodes and bone [5
]. The literature reveals only 80 cases of prostatic cancer spreading to testis and also bilateral cases were seen [6
The frequency of metastasis to the testis is very low, only 2% of the testis tumors are metastatic. Hanash et al  reviewing 5,000 autopsies have reported one case of metastasis to the testis, Pienkos and Joblokow  found an incidence of 0.06% after reviewing 24.000 autopsies and they were unable to show any prostatic metastasis in their series. Similarly, Saitoh et al  were not able to show prostatic metastasis to testis after reviewing 1885 autopsies. The clinical picture of metastasis to the testis was inconstant and usually there was no palpable mass in testis similar to our case . However, the source of inguinal pain may well be due to this metastasis in our patient.
In conclusion, if local or distant sites for relapse could not be demonstrated in a hormone refractory prostate cancer patient with PSA progression, testicles must be examined for possible metastasis.