The natural history of nephrogenic adenoma of the urinary bladder

Abstract

The nephrogenic adenoma is a peculiar lesion of the urinary bladder characterized partly by villous and partly by gland-like structures. The two layered surface epithelium consists of an eosinophilic cell layer, which covers a clear cell layer, the latter resting upon a delicate basal layer. The clear cells disappear when approaching the tip of the villi. There exists a 200 micron wide zone of transition between the urinary bladder epithelium and that of the neprogenic adenoma. At the base of the villi there are scattered nodules of gland-like structures lined either by eosinophilic cells or by clear cells. These epithelial cells are derived from the corresponding surface epithelial cells from which they had separated by active downwards growth.

Nephrogenic Adenoma of the Bladder

“…These may act as stimuli which cause proliferative and metaplastic changes of the multipotent urothelium [3]. Thus, a metaplasia seems to be more likely and adjectives like nephrogenic or tubular simply refer to the histological appearance [4], Associated pathologic findings, that is, edema and inflammatory infiltrates, squamous metaplasia, cystitis cystica and cys titis glandularis also support the interpretation that neph rogenic adenoma is of inflammatory rather than neoplasmic origin [5][6][7][8][9][10], At cystoscopy, nephrogenic adenoma may simulate a papillary, sessile, or in situ carcinoma. The single or more often multiple lesions vary from incidentally discovered microscopic lesions to masses up to 7 cm in greatest dimension [10].…”

Nephrogenic Adenoma of the Bladder in Children

“…We believe that the tumor should be followed up in the same way as an ordinary bladder tumor, especially in children [7], because of the tendency to recur [21] shown also in 2 of our cases. Experiments on animals have demonstrated beyond question the ease with which transitional cell epithelium can change into squamous cell epithelium, for instance in vitamin A deficiency, irradiation or long-lasting irrita tion, such as chronic infection.…”