Transrectal ultrasound of the prostate bed after collagen injection

Objective: Transurethral injection of collagen (TCI) may be used to treat urinary incontinence following radical prostatectomy for prostate cancer. The transrectal ultrasound (TRUS) findings after TCI are described in this report. Materials and Methods: TRUS exams of four postprostatectomy patients who had undergone TCI were reviewed. Findings were correlated with pathologic specimens obtained at TRUS-guided core biopsy. These histologic specimens were compared with others from postprostatectomy patients who had not undergone TCI. Results: Well defined bladder apex masses of uniform echogenicity, hypoechoic to adjacent fat and muscle, were identified sonographically in all TCI patients. Masses from which positive biopsies were obtained were similar in appearance to those with no malignancy. Hypocellular fibrous tissue and foci of acellular loose connective tissue were identified in the biopsies of those patients who had undergone TCI. No acellular areas were identified in specimens from patients who had not had TCI. Conclusion: Sequelae of TCI should be included in the differential diagnosis of perianastomotic masses in postprostatectomy patients. However, the need for biopsy is not obviated as residual or recurrent prostate carcinoma may coexist.