vesical glandular metaplasia

PO

Definition : Intestinal metaplasia of the bladder is a replacement of urothelium by colonic mucosa or isolated / clusters of goblet cells in Brunn nests. See also cystitis cystica / cystitis glandularis

Intestinal metaplasia (IM) of the bladder, characterized by the presence of intestinal type epithelium in the bladder, are glandular proliferation that most frequently occur on the bladder trigone.

This condition affects men much more commonly than women with an overall estimated incidence of 0.1 to 0.9 %.

Most cases of IM are diagnosed in the fifth to sixth decades of life and they are thought to be acquired secondary to persistent irritation and inflammation.

Patients have been classically considered to present with hematuria, lower urinary tract symptoms and mucosuria, although many patients instead present with nonspecific urinary complaints.

Despite an improved clinical understanding of these uncommon lesions the pathogenesis remains unclear.

Proposed etiologies of IM are congenital and acquired causes, including bladder extrophy, long-term catheterization, bladder calculi and neurogenic bladder.

The presence of IM as a precursor of adenocarcinoma, a type of bladder cancer with poor prognosis, has long been debated. In 1958, Shaw et al. published the first report implicating IM in the development of adenocarcinoma of the bladder.

After this research, sporadic case reports have associated IM with bladder adenocarcinoma, prompting consideration of IM as a preneoplastic condition.

However, the premalignant nature of IM has been questioned by the following investigators. After reviewing 53 cases, Corica et al. concluded that IM did not seem to be a risk factor for bladder cancer, and frequent and long-term follow up was not advocated if a concurrent diagnosis of malignancy was excluded.

Open references

 Intestinal metaplasia of the bladder in 89 patients: a study with emphasis on long-term outcome. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4895895/