Nephrogenic adenoma of the urinary tract: clinical, histological, and immunohistochemical characteristics

Abstract

Nephrogenic adenoma is a benign condition of the urinary tract resulting from the displacement and seeding of renal tubular cells from the renal pelvis to the urethra. A retrospective series of 134 cases collected from four hospitals in three different countries was analyzed in this study. Recorded clinical data included age and sex, topography, urological antecedents, coexistent lesions, and follow-up. Cytonuclear and architectural features were reviewed, and PAX-8, p63, PSMA, S100A1, CEA, EMA, CD117, cannabinoid receptor CB1, AMACR, E-cadherin, and CD10 antibodies were included in an immunohistochemical panel. Males predominated (105 M/29 F) with an average age of 66 years (range, 14-96). Urothelial carcinoma was the most frequent clinical antecedent (43.2 %) and also the most common coexisting lesion (14 %). Tubular architecture was the most frequent pattern detected (40 %) although most cases showed a mixed pattern (45.5 %). Deep infiltrative growth into the muscularis propria occurred in two cases. EMA and PAX-8 were expressed in 100 % of nephrogenic adenomas, while E-cadherin reactivity was observed in 66.6 % of cases, cannabinoid receptor CB1 in 25 %, CD10 in 13.6 %, CD117 in 4.1 %, and AMACR in 2.7 %. For the rest of the antigens, no reactivity was found. The average time lapse between the pathological antecedent and the discovery of a nephrogenic adenoma was 32 months. We conclude that nephrogenic adenoma displays a broad spectrum of histological features that may mimic malignancy. In our experience, CB1 immunostaining adds a further argument in favor of a renal origin of this lesion. The combination of PAX-8+, p63-, and EMA + distinguishes nephrogenic adenoma from urothelial and prostate carcinoma, its most frequent malignant look-alikes.

Nephrogenic adenoma in elderly patients: Three case reports

“…López et al analyzed 134 cases of NA with a mean patient age of 66 years, suggesting that elderly individuals appear to be more prone to development of NA (5). However, the studies of Husain et al and Kao et al involved pediatric cases of NA (8,9).…”

“…In 1950, Fiedman and Kuhlenbeck named this lesion 'nephrogenic adenoma' based on its histological similarity to renal tubules (4). It has been reported that NA mainly arises in the urinary bladder (68.6%) and urethra (13.3%), but also in the ureter (8.2%), renal pelvis (8.2%) and, rarely, in the prostate (2%) (5). NAs exhibit a male predominance, with a male:female ratio of ~3.6:1.…”

Lesions of the Female Urethra: A Review

“…51 The cause of nephrogenic adenoma has been considered to be secondary to irritation; however, the existence in children makes this theory less plausible. 50 The lesions have a recurrence potential. 37 …”

“…50,51 The lesions stain for antibodies to epithelial membrane and paired box 8. 50 Although not felt to be premalignant or malignant, there is some association with urothelial carcinoma, and the adenoma may coexist with carcinoma or be seen subsequent to urothelial carcinoma. The lesion should not be confused with urothelial carcinoma (or prostatic carcinoma in men).…”

Nephrogenic adenoma of the bladder: a case report

“…1950 yılında, Fiedman ve Kuhlenbeck tarafından histolojik yapısının renal tubullere benzerliğinden dolayı 'nefrojenik adenom' olarak adlandırılmıştır (3). Nefrojenik adenom % 68.6 ile en çok mesanede görülürken üretra(% 13.3), üreter(% 8.2), renal pelvis(% 8.2) ve nadiren de prostatta(%2) görülebilmektedir (4). Nefrojenik adenom için predispozan faktörler genitoüriner travma, geçirilmiş cerrahi, kronik inflamasyon, renal kalkül, tekrarlayan enstrumantasyon, anatomik anomali, pelvik radyasyon maruziyeti ve ibuprofen, fenasetin gibi bazı ilaçların kullanımıdır (5).…”