Seeding and perineal implantation of prostatic cancer in the track of the biopsy needle: three case reports and a review of the literature.

Several months (an average of 12.86 months) after perineal needling of the cancerous prostate for the purpose of obtaining tissue for biopsy, a tumor nodule becomes clinically evident in the subcutaneous tissue of the perineum, at the site of the needling in 0.34% of the cases. This nodule presents the same histological picture as the biopsy of the prostatic tumor. This is a review of 15 such cases (12 collected from the literature and an additional three unpublished cases, two of which are personal observations). At the time of needling, no metastases could be clinically detected in any of the patients; the serum acid phosphatase was normal in 73% of them. The average age of the patients was 65.66 years. The perineal nodule was tender in 40% of the cases; its average size was 2.5 cm. Excision of the nodule was the most frequently employed form of management. At the time of reporting, 60% of the patients were living and well, for an average of 18.56 months after excision. In order to prevent perineal implantation, especially in patients who are at risk, it is suggested that a fine needle be employed to obtain prostatic tissue for biopsy, and that every possible therapeutic effort be made.