intestinal metaplasia of the bladder mucosa

Definition: Replacement of urothelium by colonic mucosa or isolated / clusters of goblet cells in Brunn nests.

Macroscopy

 Irregular rounded focal elevations of mucosa
 Rarely polypoidal with mucinous extravasations

Microscopy

 Replacement of urothelium by colonic mucosa (tall columnar cells)
 Also goblet cells (single or aggregates) within Brunn’s nests, variable presence of Paneth cells
 May coexist with cystitis cystica or cystitis glandularis
 Mucin may be occasionally extravasated into the stroma
 No atypia, no involvement of muscularis propria

See also

 cystitis cystica / cystitis glandularis