What causes squamous metaplasia in the bladder?
Urinary Tract Irritants. Chronic irritants associated with squamous metaplasia include: indwelling catheters, urinary calculi, urinary outflow obstruction, fistula, tu- mours, bladder extrophy, neurogenic bladder, previous bladder surgery and vitamin A deficiency [3].
What is squamous metaplasia of the bladder?
Squamous metaplasia is an abnormal replacement of urothelial epithelium of urinary bladder with non-keratinizing stratified squamous epithelium. It is mostly recognized in adult women in the post-menopausal period.
Is squamous metaplasia cervix normal?
There are two types of squamous metaplasia of the urothelium, nonkeratinizing and keratinizing. The former is considered as a normal finding in females, present in the trigone and bladder neck in up to 85% of women of reproductive age and 75% of postmenopausal women.
What is cervical squamous metaplasia?
Squamous metaplasia in the cervix refers to the physiological replacement of the everted columnar epithelium on the ectocervix by a newly formed squamous epithelium from the subcolumnar reserve cells. The region of the cervix where squamous metaplasia occurs is referred to as the transformation zone.
What does squamous metaplasia on a Pap smear mean?
Squamous metaplasia, the process by which mature, non-squamous epithelium is replaced by stratified squamous epithelium, is a well-described phenomenon in the endocervical canal of both women and laboratory animals. In the human cervix, this process has been shown to develop in stages.
How is squamous metaplasia treated?
Conclusion: The therapeutic management of keratinizing squamous metaplasia is controversial, and currently no effective medical therapy is available for its treatment. Actually, patients undergo transurethral resections and a multidisciplinary approach is required to avoid cystectomy.
What causes cervical metaplasia?
During puberty and at the first pregnancy the cervix increases in volume in response to hormonal changes. The endocervical epithelium everts onto the ectocervix (portio vaginalis) exposing it to the acid pH of the vagina. This provides a stimulus for metaplastic change of the columnar epithelium.
Is squamous metaplasia in bladder?
Keratinizing squamous metaplasia of the bladder is rare and is usually associated with urinary tract infections and chronic irritation. It is considered a precancerous condition of squamous cell carcinoma, especially when more than 50% of the bladder surface is affected.
Is cervical metaplasia bad?
Although cervical metaplasia is prevalent among sexually active adolescents, placing them at increased risk for HPV infection, immune system clearance within 1-2 years is common. In addition, invasive cervical cancer is rare among adolescents, and most cervical dysplasias resolve spontaneously.
What causes squamous metaplasia of cervix?
Factors in the initiation and promotion of squamous metaplasia are chronic irritation of a physical nature, such as that caused by an intrauterine contraceptive device (IUD), chemical irritants, inflammation with cell destruction, and endocrine changes at the beginning of, during, and after reproductive age.