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Necrotizing Sialometaplasia

Necrotizing Sialometaplasias

Necrotizing sialometaplasia is a rare, benign inflammatory disease of the minor mucous salivary glands usually caused by glandular ischemia or trauma, that can mimic malignancy, but has a self-limiting character. Physicians should be aware of its clinical and histological traits in order to avoid unnecessary disfiguring surgery.


Necrotizing sialometaplasia usually presents suddenly and can be precipitated by trauma, vomiting [1], surgery [2] or radiation therapy. Cases may also occur in patients with neoplasia or chronic inflammatory diseases and have also been reported after mucocele excision [3].

Physical examination reveals the pathological process as an inflammation and swelling of a minor salivary gland located in the hard palate area [4] that can also take the form of an ulcer, usually with a diameter of 0.7 to 5 cm [5]. Lesions may also be bilateral [6] or located in other regions of the oral cavity like incisive canal, maxillary sinus, parotid glands [7], tongue [8], nasal cavity [9], larynx [10] or other sites in the upper respiratory tract [11], including the trachea [12], but usually involve the palatal midline [13]. Necrotizing sialometaplasia of the breast [14], skin (in this case being termed syringometaplasia [15]) and lungs [16] have also been published. Palatal bone erosion may occur with both ulcerated and non-ulcerated lesions, making it difficult to distinguish from malignant tumors. Wegener granulomatosis, abscesses, and extranodal lymphoma must also be excluded, and this is only possible after performing a biopsy. With prolonged evolution, spontaneous healing is usually observed [11].

The lesions are accompanied by general symptoms, such as malaise, fever, and chills and may be painful or can be associated with a loss of sensations over the mucosa of the palate [17]. They occur more often in men in the fourth decade of life [18].

Relapsing Polychondritis
  • Subsequently, the patient was diagnosed as having relapsing polychondritis, the probable cause of the subglottic stenosis. The male patient presented with increasing hoarseness and was found to have a mass of the right false vocal cord.[ncbi.nlm.nih.gov]
Parotid Mass
  • We report a case of necrotizing sialometaplasia diagnosed after superficial parotidectomy due to bilateral parotid masses in a 69-year old heavy smoking female.[ncbi.nlm.nih.gov]
Parotid Mass
  • We report a case of necrotizing sialometaplasia diagnosed after superficial parotidectomy due to bilateral parotid masses in a 69-year old heavy smoking female.[ncbi.nlm.nih.gov]
  • These findings suggest that vascular occlusion by the neoplastic cells produces ischemia, which leads to local infarction contributing to the salivary gland lesion.[ncbi.nlm.nih.gov]
  • Suomalainen et al 12 suggested that the degree of the inflammatory reaction can be reflected in the above stages of NS.[doi.org]
  • This latter clinically suggests a benign process.[ncbi.nlm.nih.gov]
  • We suggest an aggressive diagnostic approach, when necrotizing sialometaplasia involves the larynx and no recent exposure to radiation, surgery or trauma has been recorded.[ncbi.nlm.nih.gov]
  • Although its etiopathogenesis remains still unknown some authors suggest that a physico-chemical or biological injury on the blood vessels may produce ischemic changes, leading to infarction of the gland and its further necrosis.[ncbi.nlm.nih.gov]
Neck Mass
  • In this case, the patient first presented with a neck mass which could easily have been mistaken for a regional metastasis. The current literature is reviewed.[ncbi.nlm.nih.gov]
  • Necrotizing sialometaplasia, a benign self-limiting disease of minor salivary glands, may be confused both clinically and histologically with squamous cell carcinoma or a minor salivary gland neoplasm.[ncbi.nlm.nih.gov]
  • Necrotizing sialometaplasia is a benign self-limited intraoral lesion that is easily confused both clinically and histologically with squamous cell carcinoma.[ncbi.nlm.nih.gov]
  • This, as well as the histopathologic findings of necrotizing sialometaplasia, can be confused with those of a malignant neoplasm.[ncbi.nlm.nih.gov]
  • This lesion is easily confused with squamous cell carcinoma or mucoepidermoid carcinoma because clinical and histological appearances are similar. A twenty-threeyear-old female was referred to us complaining of swollen palate.[jstage.jst.go.jp]
  • It is often confused clinically and histopathologically with malignancies, such as squamous cell carcinoma or mucoepidermoid carcinoma.[infona.pl]


A radiography of the affected area is needed in the presence of palatal bone erosion [19] [11], but the definite diagnosis depends on histological examination of a biopsy specimen which must be taken from the base and margin of the ulcer and should be large and deep enough to ensure proper analysis, in order not to erroneously diagnose pseudoepitheliomatous mucous hyperplasia, mucoepidermoid carcinoma or squamous cell carcinoma. Microscopic examination reveals squamous ductal metaplasia and necrosis of the minor salivary glands. An inflammatory infiltrate composed of neutrophils, macrophages, eosinophils, plasma cells and lymphocytes (mixed inflammatory reaction), as well as mucin extravasation [4] and necrotizing sialadenitis are also present. Lobular architecture is not disrupted.

If the diagnosis remains uncertain, immunohistochemistry study is indicated. This evaluation will show no p53 immunoreactivity, low MIB1 (Ki-67) immunoreactivity and the presence of 4A4/p63 and calponin-positive myoepithelial cells. Other markers that may prove useful are smooth muscle antibody and p63. Basement membrane markers like E-cadherin, type IV laminin, and various cytokeratins (CK5, CAM 5.2, CK6, CK7,) can also be used [20] [21]. Hematoxylin-eosin staining should also be performed [22]. Depending on the time when a biopsy is obtained, the patient could be in one of the following stages: infarction, sequestration, ulceration, repair or healing [23]. Epithelial atypia may also be present. These may coexist in different areas of the lesion and their extent depends on the healing ability of the patient.


  • The clinical and histological similarity between this entity and a malignant lesion may result in unnecessary or mis-treatment.[ncbi.nlm.nih.gov]
  • The ulcers spontaneously healed within 8 weeks without treatment. The clinical and histological similarity between this entity and a malignant lesion implies a risk of unnecessary or inadequate treatment.[ncbi.nlm.nih.gov]
  • This case has been presented to alert the practitioner to the possibility that NS may obscure an underlying malignant disease process, possibly resulting in delays in referral or treatment.[ncbi.nlm.nih.gov]
  • It is important to recognize this condition to prevent unnecessary investigations and treatment being carried out.[ncbi.nlm.nih.gov]
  • We also investigated the use of pre-operative imaging based on previous reports and discuss the importance of these images in helping to guard against overzealous treatment.[ncbi.nlm.nih.gov]


  • Prognosis The prognosis for necrotizing sialometaplasia (NS) is excellent.[emedicine.com]
  • Topics covered include: incidence etiology clinical presentation pathology differential diagnosis prognosis for each disorder With an improved format and design as well as an easy-to-use, quick reference index, the updated and expanded Third Edition contains[books.google.com]
  • Prognosis is good once it is diagnosed accurately. [1] In our case, the lesion showed signs of remission after 2 weeks of follow-up. Complete remission of the lesion was observed approximately after 8 weeks.[ijds.in]
  • The prognosis is excellent, once the correct diagnosis is made. There are no known preventative strategies. If the lesions are large, incisional biopsy should be done to establish a definitive diagnosis.[exodontia.info]


  • The etiology of this rare inflammatory disorder is related to an ischemic event. Identified risk factors include alcohol abuse, smoking, drugs, denture wearing, injury and systemic diseases.[ncbi.nlm.nih.gov]
  • The etiology of NS remains unknown, but it may be associated with local trauma, use of a denture, arteriosclerosis or allergy. Most investigators seem to favor an ischemic cause of NS.[ncbi.nlm.nih.gov]
  • It emphasizes the importance of confirming the diagnosis by incisional biopsy and discusses local mucosal trauma as a possible etiologic factor.[ncbi.nlm.nih.gov]
  • Its etiology is thought to be an insufficient blood supply. Bilateral involvement of this disease in parotid glands has been rarely reported in the English literature.[ncbi.nlm.nih.gov]
  • The etiology of the lesion was considered to be ischemia secondary to compression by the necrotic myocutaneous flap.[ncbi.nlm.nih.gov]


  • Epidemiology Frequency United States Mesa and colleagues reported an incidence of 0.03% based on findings in 10,000 oral biopsy specimens. [16] However, they state that this percentage does not account for cases of necrotizing sialometaplasia that heal[emedicine.com]
Sex distribution
Age distribution


  • Pathophysiology Necrotizing sialometaplasia was first reported to involve the minor salivary glands of the oral cavity, particularly those of the palate.[emedicine.com]
  • Submitted abstracts will be reviewed by a committee composed of both patients and research experts and The National Psoriasis.Psoriasis – Pathophysiology, Conventional, and Alternative Approaches to Treatment Michael Traub, ND, Psoriasis is considered[ysokone.webcindario.com]


  • Because necrotizing sialometaplasia may be misdiagnosed as squamous cell carcinoma or mucoepidermoid carcinoma, it is important that the clinician and pathologist take the necessary precautions to prevent any further mutilative surgery for this benign[ncbi.nlm.nih.gov]
  • A high index of suspicion and good communication between clinician and pathologist are essential in recognizing this entity and preventing unnecessary surgical therapy.[ncbi.nlm.nih.gov]
  • Pathologists and clinicians should be aware of these entities to prevent misdiagnosis. This is the first clinical report of 2 rare and consecutive different entities of the same location on the hard palate to our knowledge.[ncbi.nlm.nih.gov]
  • To prevent over-diagnosis and over-treatment of presumed malignancies, an awareness of necrotizing sialometaplasia is essential for all surgeons operating on mucosal surfaces in the head and neck.[ncbi.nlm.nih.gov]
  • It is important to recognize this condition to prevent unnecessary investigations and treatment being carried out.[ncbi.nlm.nih.gov]



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  2. Aframian D, Milhem I, Kirsch G, et al. Necrotizing Sialometaplasia after Silastic Ring Vertical Gastroplasty: Case Report and Review of Literature. Obes Surg. 1995;5(2):179-182.
  3. Pulse C, Lebovics R, Zagarelli D. Necrotizing sialometaplasia: Report of a case after lower lip mucocele excision. J Oral Maxillofac Surg. 2000;58:1419–1421.
  4. Abrams A, Melrose R, Howell F. Necrotizing sialometaplasia. A disease simulating malignancy. Cancer. 1973;32:130–135.
  5. Nah K, Cho B, Jung Y. Necrotizing sialometaplasia: report of 2 cases. Korean J Oral Maxillofac Radiol. 2006;36:207–209.
  6. Niedzielska I, Janic T, Markowski J. Bilateral localization of necrotizing sialometaplasia: a case report. Cases J. 2009;8(2):9068.
  7. Prabhakaran V, Flora R, Kendall C. Pressure-induced necrotizing sialometaplasia of the parotid gland. Histopathology. 2006;48:464–465.
  8. Randhawa T, Varghese I, Shameena P, et al. Necrotizing sialometaplasia of tongue. J Oral Maxillofac Pathol. 2009;13:35–37.
  9. Chen KT. Necrotizing sialometaplasia of the nasal cavity. Am J Otolaryngol. 1982;3:444–446.
  10. Walker G, Fechner R, Johns M, et al. Necrotizing sialometaplasia of the larynx secondary to atheromatous embolization. Am J Clin Pathol. 1982;77:221–223.
  11. Brannon R, Fowler C, Hartman K. Necrotizing sialometaplasia: a clinicopathologic study of sixty-nine cases and review of the literature. Oral Surg Oral Med Oral Pathol. 1991;72:317–325.
  12. Romagossa V, Bella M, Truchero C, et al. Necrotizing sialometaplasia (adenometaplasia) of the trachea. Histopathology. 1992;21:280–282.
  13. Keogh P, O'Regan E, Toner M, et al. Necrotizing sialometaplasia: an unusual bilateral presentation associated with antecedent anaesthesia and lack of response to intralesional steroids. Case report and review of the literature. Br Dent J. 2004;196:79–81.
  14. Hurt MA, Díaz-Arias A, Rosenholtz M, et al. Posttraumatic lobular squamous metaplasia of breast. An unusual pseudocarcinomatous metaplasia resembling squamous (necrotizing) sialometaplasia of the salivary gland. Mod Pathol. 1988;1:385–390.
  15. King D, Barr R. Syringometaplasia: mucinous and squamous variants. J Cutan Pathol. 1979;6:284–291.
  16. Zschoch H. Mucus gland infarct with squamous epithelial metaplasia in the lung. A rare site of so-called necrotizing sialometaplasia. Pathology. 1992;13:45–48.
  17. Lamey P, Lewis M, Crawford D, et al. Necrotising sialometaplasia presenting as greater palatine nerve anaesthesia. Int J Oral Maxillofac Surg. 1989;18:70–72.
  18. Penner C, Thompson L. Necrotizing sialometaplasia. Ear Nose Throat J. 2003;82(7):493–494.
  19. Aframian D. Necrotizing sialometaplasia-a practical approach to the diagnosis. Arch Pathol Lab Med. 2010;134(1):17.
  20. Zarovnaya E, Black C. Distinguishing pseudoepitheliomatous hyperplasia from squamous cell carcinoma in mucosal biopsy specimens from the head and neck. Arch Pathol Lab Med. 2005;129:1032–1036.
  21. Rizkalla H, Toner M. Necrotizing sialometaplasia versus invasive carcinoma of the head and neck: the use of myoepithelial markers and keratin subtypes as an adjunct to diagnosis. Histopathology. 2007;51:184–189.
  22. Carlson D. Necrotizing sialometaplasia: a practical approach to the diagnosis. Arch Pathol Lab Med. 2009;133:692–698.
  23. Anneroth G, Hansen L. Necrotizing sialometaplasia. The relationship of its pathogenesis to its clinical characteristics. Int J Oral Surg. 1982;11:283–291.

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Last updated: 2019-07-11 20:22