Necrotizing sialometaplasia | |
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Specialty | ENT surgery |
Necrotizing sialometaplasia (NS) is a benign, ulcerative lesion, usually located towards the back of the hard palate. It is thought to be caused by ischemic necrosis (death of tissue due to lack of blood supply) of minor salivary glands in response to trauma. Often painless, the condition is self-limiting and should heal in 6–10 weeks.
Although entirely benign and requiring no treatment, due to its similar appearance to oral cancer, it is sometimes misdiagnosed as malignant. Therefore, it is considered an important condition, despite its rarity.
The condition most commonly is located at the junction of the hard and soft palate. [1] However, the condition may arise anywhere minor salivary glands are located. [nb 1] It has also been occasionally reported to involve the major salivary glands. [2] [3] It may be present only on one side, or both sides. [1] The lesion typically is 1–4 cm in diameter. [4]
Initially, the lesion is a tender, erythematous (red) swelling. Later, in the ulcerated stage, the overlying mucosa breaks down to leave a deep, well-circumscribed ulcer which is yellow-gray in color and has a lobular base. [1]
There is usually only minor pain, [1] and the condition is often entirely painless. There may be prodromal symptoms similar to flu before the appearance of the lesion. [4]
The exact cause of the condition is unknown. [4] [5] There is most evidence to support vascular infarction and ischemic necrosis of salivary gland lobules as a mechanism for the condition. [6] Experimentally, local anaesthetic injections and tying of the arteries is reported to trigger the development of tissue changes similar to NS in lab rats. [6] Factors which are thought to cause this ischemia are listed below, however sometimes there is no evident predisposing factor or initiating event. [6]
Differentiation between this and SCC would be based on a history of recent trauma or dental treatment in the area.
Immunohistochemistry may aid the diagnosis. If the lesion is NS, there will be focal to absent immunoreactivity for p53, low immunoreactivity for MIB1 (Ki-67), and the presence of 4A4/p63- and calponin-positive myoepithelial cells. [2]
No surgery is required. [4]
Healing is prolonged, and usually takes 6–10 weeks. [1] The ulcer heals by secondary intention. [7]
The condition is rare. [8] [9] The typical age range of those affected by the condition is about 23–66 years of age. [4] It usually occurs in smokers. [9] The male to female ratio has been reported as 1.95:1, [5] and 2.31:1. [10]
A mouth ulcer (aphtha), or sometimes called a canker sore or salt blister, is an ulcer that occurs on the mucous membrane of the oral cavity. Mouth ulcers are very common, occurring in association with many diseases and by many different mechanisms, but usually there is no serious underlying cause. Rarely, a mouth ulcer that does not heal may be a sign of oral cancer. These ulcers may form individually or multiple ulcers may appear at once. Once formed, an ulcer may be maintained by inflammation and/or secondary infection.
Aphthous stomatitis, or recurrent aphthous stomatitis (RAS), commonly referred to as a canker sore or salt blister, is a common condition characterized by the repeated formation of benign and non-contagious mouth ulcers (aphthae) in otherwise healthy individuals.
Stomatitis is inflammation of the mouth and lips. It refers to any inflammatory process affecting the mucous membranes of the mouth and lips, with or without oral ulceration.
The frenulumof the tongue, tongue web, lingual frenulum, frenulum linguae, or fraenulum is a small fold of mucous membrane extending from the floor of the mouth to the midline of the underside of the human tongue.
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.
A ranula is a mucus extravasation cyst involving a sublingual gland and is a type of mucocele found on the floor of the mouth. Ranulae present as a swelling of connective tissue consisting of collected mucin from a ruptured salivary gland caused by local trauma. If small and asymptomatic further treatment may not be needed, otherwise minor oral surgery may be indicated.
Epulis fissuratum is a benign hyperplasia of fibrous connective tissue which develops as a reactive lesion to chronic mechanical irritation produced by the flange of a poorly fitting denture. More simply, epulis fissuratum is where excess folds of firm tissue form inside the mouth, as a result of rubbing on the edge of dentures that do not fit well. It is a harmless condition and does not represent oral cancer. Treatment is by simple surgical removal of the lesion, and also by adjustment of the denture or provision of a new denture.
Inflammatory papillary hyperplasia (IPH) is a benign lesion of the oral mucosa which is characterized by the growth of one or more nodular lesions, measuring about 2mm or less. The lesion almost exclusively involves the hard palate, and in rare instances, it also has been seen on the mandible. The lesion is mostly asymptomatic and color of the mucosa may vary from pink to red.
An oral medicine or stomatology doctor/dentist has received additional specialized training and experience in the diagnosis and management of oral mucosal abnormalities including oral cancer, salivary gland disorders, temporomandibular disorders and facial pain, taste and smell disorders; and recognition of the oral manifestations of systemic and infectious diseases. It lies at the interface between medicine and dentistry. An oral medicine doctor is trained to diagnose and manage patients with disorders of the orofacial region.
Stomatitis nicotina is a diffuse white patch on the hard palate, usually caused by tobacco smoking, usually pipe or cigar smoking. It is painless, and it is caused by a response of the palatal oral mucosa to chronic heat. A more pronounced appearance can occur with reverse smoking, sometimes distinguished from stomatitis nicotina by the term reverse smoker's stomatitis. While stomatitis nicotina that is caused by heat is not a premalignant condition, the condition that is caused by reverse smoking is premalignant.
The Stafne defect is a depression of the mandible, most commonly located on the lingual surface. The Stafne defect is thought to be a normal anatomical variant, as the depression is created by ectopic salivary gland tissue associated with the submandibular gland and does not represent a pathologic lesion as such. This cavity is commonly observed on panoramic radiograph.
A glandular odontogenic cyst (GOC) is a rare and usually benign odontogenic cyst developed at the odontogenic epithelium of the mandible or maxilla. Originally, the cyst was labeled as "sialo-odontogenic cyst" in 1987. However, the World Health Organization (WHO) decided to adopt the medical expression "glandular odontogenic cyst". Following the initial classification, only 60 medically documented cases were present in the population by 2003. GOC was established as its own biological growth after differentiation from other jaw cysts such as the "central mucoepidermoid carcinoma (MEC)", a popular type of neoplasm at the salivary glands. GOC is usually misdiagnosed with other lesions developed at the glandular and salivary gland due to the shared clinical signs. The presence of osteodentin supports the concept of an odontogenic pathway. This odontogenic cyst is commonly described to be a slow and aggressive development. The inclination of GOC to be large and multilocular is associated with a greater chance of remission. GOC is an infrequent manifestation with a 0.2% diagnosis in jaw lesion cases. Reported cases show that GOC mainly impacts the mandible and male individuals. The presentation of GOC at the maxilla has a very low rate of incidence. The GOC development is more common in adults in their fifth and sixth decades.
Median palatal cysts are uncommon hard palate fissural cysts that are not odontogenic. These lesions are located behind the incisive canal in the midline of the hard palate. The majority of the time, median palatine cysts are asymptomatic and are discovered by coincidence while a patient is being evaluated for a different ailment.
Oral and maxillofacial pathology refers to the diseases of the mouth, jaws and related structures such as salivary glands, temporomandibular joints, facial muscles and perioral skin. The mouth is an important organ with many different functions. It is also prone to a variety of medical and dental disorders.
Oral pigmentation is asymptomatic and does not usually cause any alteration to the texture or thickness of the affected area. The colour can be uniform or speckled and can appear solitary or as multiple lesions. Depending on the site, depth, and quantity of pigment, the appearance can vary considerably.
Epulis is any tumor-like enlargement situated on the gingival or alveolar mucosa. The word literally means "(growth) on the gingiva", and describes only the location of the mass and has no further implications on the nature of the lesion. There are three types: fibromatous, ossifying and acanthomatous. The related term parulis refers to a mass of inflamed granulation tissue at the opening of a draining sinus on the alveolus over the root of an infected tooth. Another closely related term is gingival enlargement, which tends to be used where the enlargement is more generalized over the whole gingiva rather than a localized mass.
Salivary gland diseases (SGDs) are multiple and varied in cause. There are three paired major salivary glands in humans: the parotid glands, the submandibular glands, and the sublingual glands. There are also about 800–1,000 minor salivary glands in the mucosa of the mouth. The parotid glands are in front of the ears, one on side, and secrete mostly serous saliva, via the parotid ducts, into the mouth, usually opening roughly opposite the second upper molars. The submandibular gland is medial to the angle of the mandible, and it drains its mixture of serous and mucous saliva via the submandibular duct into the mouth, usually opening in a punctum in the floor of mouth. The sublingual gland is below the tongue, on the floor of the mouth; it drains its mostly mucous saliva into the mouth via about 8–20 ducts, which open along the plica sublingualis, a fold of tissue under the tongue.
A sialocele is a localized, subcutaneous cavity containing saliva. It is caused by trauma or infection. They most commonly develop about 8–14 days after injury.
Chronic sclerosing sialadenitis is a chronic (long-lasting) inflammatory condition affecting the salivary gland. Relatively rare in occurrence, this condition is benign, but presents as hard, indurated and enlarged masses that are clinically indistinguishable from salivary gland neoplasms or tumors. It is now regarded as a manifestation of IgG4-related disease.
Smokeless tobacco keratosis (STK) is a condition which develops on the oral mucosa in response to smokeless tobacco use. Generally it appears as a white patch, located at the point where the tobacco is held in the mouth. The condition usually disappears once the tobacco habit is stopped. It is associated with slightly increased risk of mouth cancer.