NEPHROGENIC ADENOMA AFTER URETHRAL RECONSTRUCTION USING BLADDER MUCOSA - REPORT OF 6 CASES AND REVIEW OF THE LITERATURE

Purpose: To our knowledge nephrogenic adenoma, an unusual benign metap lastic lesion of the urothelium, has not been reported previously foll owing urethral reconstruction using bladder mucosa. Histopathological features, etiological factors and clinical features are discussed. Mat erials and Methods: We reviewed the records of 117 patients who underw ent hypospadias repair with free grafts of bladder mucosa from 1982 to 1995. Results: Five children 6 to 11 years old and a 39-year-old man had nephrogenic adenoma of the urethra. Hematuria or dysuria was the u sual reason for presentation. The lesions were located at the site of anastomosis between the graft and proximal urethra in 3 cases and the distal graft in 2, and they involved the whole graft in 1. Successful treatment consisted of endoscopic resection of the polyps in 4 patient s, while open surgical correction was performed in 2, requiring comple te excision of the previous graft in 1 and segmental resection in 1. C onclusions: The gross appearance of the lesion may be confused with th at of transitional cell carcinoma or clear cell adenocarcinoma of the urethra, necessitating biopsy to rule out malignancy. Endoscopic manag ement is possible for small tumors, although severe nephrogenic adenom a involving most of the reconstructed urethra may require complete res ection of the graft and creation of a new urethra.