Recurrence of mucinous prostate cancer in rectal wall due to needle-track seeding from previous transrectal prostate biopsy

Introduction: Needle-track seeding of prostate cancer into the rectal wall following transrectal prostate biopsy is exceedingly rare. We report a case of mucinous prostate cancer recurrence in the rectal wall due to biopsy needle seeding, discovered after robot-assisted radical prostatectomy.

Case presentation: A 67-year-old man underwent robot-assisted radical prostatectomy for mucinous prostate cancer (clinical stage T2cN0M0, Gleason score of 4 + 4, and initial prostate-specific antigen level of 8.8 ng/mL). Five years postoperatively, endoscopy revealed a rectal tumor, which was diagnosed as needle-track seeding from the previous transrectal prostate biopsy. Following resection of this rectal tumor, the patient's prostate-specific antigen level fell to <0.008 ng/mL. No signs of recurrence or metastasis were observed 3 months postoperatively.

Conclusion: While rare, transrectal prostate biopsies can pose a small risk of needle-track seeding into the rectal wall. Endorectal examination should be considered if biochemical recurrence of prostate cancer occurs following radical prostatectomy.