[Florid glandular cystitis of the intestinal type with mucin extravasation: a lesion simulating a tumor].

A wide spectrum of glandular epitheliales metaplastic changes may be seen in the bladder. Extensive replacement of the urotelium with an epithelium resembling intestinal mucosa is recognised as a premalignant condition. However, the natural history of intestinal metaplasia of the urinary bladder and long-term outcome are unknown. We report a case of glandular cystitis with intestinal metaplasia in a young patient. Cystoscopy revealed a tumour well circumscribed measuring 4 cm on the trigone. Microscopic examination showed numerous glands lined by intestinal type epithelium without atipia, conforming to the appearance of the intestinal variant of cystitis glandularis. This case had prominent foci of basophilic mucin in the stroma. Rounded aggregates of mucin were occasionally surrounded by compressed connective tissue cells, simulating mucinous cyst. This case illustrates the extent to which cystitis glandularis may mimic a neoplasm on gross evaluation and the propensity of mucin extravasation to cause diagnostic difficulty, a finding documented only rarely previously, and we discuss its biologic significance.