Ectopic prostate tissue presenting as a giant pelvic mass with seeding nodules

We report a case of ectopic prostate tissue presenting as multiple lesions resembling a giant pelvic mass with seeding nodules. A 60-year-old man was admitted to the general surgery department of our hospital with an incidentally discovered pelvic mass on computed tomography performed at an outside hospital. The computed tomography scan showed a well-demarcated heterogeneous enhancing mass of 14 cm on the right side of the urinary bladder, and other similarly small nodules were observed in the pelvic cavity and perianal area. Physical examination showed a palpable mass in the suprapubic area; however, the patient did not complain of urinary system symptoms. Laboratory examination showed an elevated level of prostate-specific antigen (12.18 ng/mL). Suprapubic incision and mass resection were performed. The surgeon removed two of the masses and dissected the pelvic lymph nodes. Pathological examination confirmed that both masses were ectopic prostate tissues, and focal adenocarcinoma (<5%) was noted in the largest mass (Gleason score, 3 + 3 = 6). The Prostate-specific antigen level returned to normal postoperatively.