Squamous metaplasia is a benign non-cancerous change (metaplasia) of surfacing lining cells (epithelium) to a squamous morphology.
Squamous metaplasia is a benign non-cancerous change (metaplasia) of surfacing lining cells (epithelium) to a squamous morphology.
Common sites for squamous metaplasia include the bladder and cervix. Smokers often exhibit squamous metaplasia in the linings of their airways. These changes don't signify a specific disease, but rather usually represent the body's response to stress or irritation. Vitamin A deficiency or overdose can also lead to squamous metaplasia. [1]
In regard to the cervix, squamous metaplasia can sometimes be found in the endocervix, as it is composed of simple columnar epithelium, whereas the ectocervix is composed of stratified squamous non-keratinized epithelium. [2]
Squamous metaplasia may be seen in the context of benign lesions (e.g., atypical polypoid adenomyoma), chronic irritation, or cancer (e.g., endometrioid endometrial carcinoma), as well as pleomorphic adenoma.
The cervix or cervix uteri is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long and roughly cylindrical in shape, which changes during pregnancy. The narrow, central cervical canal runs along its entire length, connecting the uterine cavity and the lumen of the vagina. The opening into the uterus is called the internal os, and the opening into the vagina is called the external os. The lower part of the cervix, known as the vaginal portion of the cervix, bulges into the top of the vagina. The cervix has been documented anatomically since at least the time of Hippocrates, over 2,000 years ago.
Epithelium or epithelial tissue is a thin, continuous, protective layer of compactly packed cells with a little intercellular matrix. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin. Epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. These tissues also lack blood or lymph supply. The tissue is supplied by nerves.
Endometrial cancer is a cancer that arises from the endometrium. It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most often vaginal bleeding not associated with a menstrual period. Other symptoms include pain with urination, pain during sexual intercourse, or pelvic pain. Endometrial cancer occurs most commonly after menopause.
Oral leukoplakia is a potentially malignant disorder affecting the oral mucosa. It is defined as "essentially an oral mucosal white lesion that cannot be considered as any other definable lesion." Oral leukoplakia is a white patch or plaque that develops in the oral cavity and is strongly associated with smoking. Leukoplakia is a firmly attached white patch on a mucous membrane which is associated with increased risk of cancer. The edges of the lesion are typically abrupt and the lesion changes with time. Advanced forms may develop red patches. There are generally no other symptoms. It usually occurs within the mouth, although sometimes mucosa in other parts of the gastrointestinal tract, urinary tract, or genitals may be affected.
A serous tumour is a neoplasm that typically has papillary to solid formations of tumor cells with crowded nuclei, and which typically arises on the modified Müllerian-derived serous membranes that surround the ovaries in females. Such ovarian tumors are part of the surface epithelial-stromal tumour group of ovarian tumors. They are common neoplasms with a strong tendency to occur bilaterally, and they account for approximately a quarter of all ovarian tumors.
Metaplasia is the transformation of a cell type to another cell type. The change from one type of cell to another may be part of a normal maturation process, or caused by some sort of abnormal stimulus. In simplistic terms, it is as if the original cells are not robust enough to withstand their environment, so they transform into another cell type better suited to their environment. If the stimulus causing metaplasia is removed or ceases, tissues return to their normal pattern of differentiation. Metaplasia is not synonymous with dysplasia, and is not considered to be an actual cancer. It is also contrasted with heteroplasia, which is the spontaneous abnormal growth of cytologic and histologic elements. Today, metaplastic changes are usually considered to be an early phase of carcinogenesis, specifically for those with a history of cancers or who are known to be susceptible to carcinogenic changes. Metaplastic change is thus often viewed as a premalignant condition that requires immediate intervention, either surgical or medical, lest it lead to cancer via malignant transformation.
The International Classification of Diseases for Oncology (ICD-O) is a domain-specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. This classification is widely used by cancer registries.
The oral mucosa is the mucous membrane lining the inside of the mouth. It comprises stratified squamous epithelium, termed "oral epithelium", and an underlying connective tissue termed lamina propria. The oral cavity has sometimes been described as a mirror that reflects the health of the individual. Changes indicative of disease are seen as alterations in the oral mucosa lining the mouth, which can reveal systemic conditions, such as diabetes or vitamin deficiency, or the local effects of chronic tobacco or alcohol use. The oral mucosa tends to heal faster and with less scar formation compared to the skin. The underlying mechanism remains unknown, but research suggests that extracellular vesicles might be involved.
Lactiferous ducts are ducts that converge and form a branched system connecting the nipple to the lobules of the mammary gland. When lactogenesis occurs, under the influence of hormones, the milk is moved to the nipple by the action of smooth muscle contractions along the ductal system to the tip of the nipple. They are also referred to as galactophores, galactophorous ducts, mammary ducts, mamillary ducts or milk ducts.
The cervical canal is the spindle-shaped, flattened canal of the cervix, the neck of the uterus.
A dentigerous cyst, also known as a follicular cyst, is an epithelial-lined developmental cyst formed by accumulation of fluid between the reduced enamel epithelium and the crown of an unerupted tooth. It is formed when there is an alteration in the reduced enamel epithelium and encloses the crown of an unerupted tooth at the cemento-enamel junction. Fluid is accumulated between reduced enamel epithelium and the crown of an unerupted tooth.
A stratified squamous epithelium consists of squamous (flattened) epithelial cells arranged in layers upon a basal membrane. Only one layer is in contact with the basement membrane; the other layers adhere to one another to maintain structural integrity. Although this epithelium is referred to as squamous, many cells within the layers may not be flattened; this is due to the convention of naming epithelia according to the cell type at the surface. In the deeper layers, the cells may be columnar or cuboidal. There are no intercellular spaces. This type of epithelium is well suited to areas in the body subject to constant abrasion, as the thickest layers can be sequentially sloughed off and replaced before the basement membrane is exposed. It forms the outermost layer of the skin and the inner lining of the mouth, esophagus and vagina.
Cervical ectropion is a condition in which the cells from the 'inside' of the cervical canal, known as glandular cells, are present on the 'outside' of the vaginal portion of the cervix. The cells on the 'outside' of the cervix are typically squamous epithelial cells. Where the two cells meet is called the transformation zone, also known as the stratified squamous epithelium. Cervical ectropion can be grossly indistinguishable from early cervical cancer and must be evaluated by a physician to determine risks and prognosis. It may be found incidentally when a vaginal examination is done. The area may look red because the glandular cells are red. While many women are born with cervical ectropion, it can be caused by a number of reasons, such as:
In cell biology and pathophysiology, cellular adaptation refers to changes made by a cell in response to adverse or varying environmental changes. The adaptation may be physiologic (normal) or pathologic (abnormal).
Also called Zuska's disease, subareolar abscess is a subcutaneous abscess of the breast tissue beneath the areola of the nipple. It is a frequently aseptic inflammation and has been associated with squamous metaplasia of lactiferous ducts.
Cervical cancer staging is the assessment of cervical cancer to determine the extent of the disease. This is important for determining disease prognosis and treatment. Cancer staging generally runs from stage 0, which is pre-cancerous or non-invasive, to stage IV, in which the cancer has spread throughout a significant part of the body.
Villoglandular adenocarcinoma of the cervix is a rare type of cervical cancer that, in relation to other cervical cancers, is typically found in younger women and has a better prognosis.
Microglandular hyperplasia (MGH) of the cervix is an epithelial benign abnormality (lesion) associated with gland proliferation. It can terminate in mature squamous metaplasia, and it is suspected reserve cells are involved in this process, perhaps in the form of reserve cell hyperplasia with glandular differentiation.
Squamous-cell carcinoma (SCC), also known as epidermoid carcinoma, comprises a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on the lining of the respiratory and digestive tracts.
Ovarian squamous cell carcinoma (oSCC) or squamous ovarian carcinoma (SOC) is a rare tumor that accounts for 1% of ovarian cancers. Included in the World Health Organization's classification of ovarian cancer, it mainly affects women above 45 years of age. Survival depends on how advanced the disease is and how different or similar the individual cancer cells are.