Necrotizing sialometaplasia: a malignant masquerade but questionable precancerous lesion, report of four cases.

BACKGROUND: Necrotizing sialometaplasia (NSM) is an extremely rare benign lesion with an uncertain pathogenesis. The differential diagnosis of this lesion is challenging due to little familiarity with this entity and histologic similarity with carcinomas, especially mucoepidermoid carcinoma (MEC). The purpose of this study is to raise awareness about NSM, which is often overlooked or misdiagnosed as malignancy in a small biopsy. METHODS: We reviewed all biopsy materials taken from the oral cavity in a single institution in Korea from 2012 to 2018 and found 4 cases of NSM out of 726. Clinicopathologic characteristics and comparison with other lesions were discussed. RESULTS: Unlike previous reports, patients in our series were relatively young, and NSM was not related to smoking and not associated with malignancies, although one patient was misdiagnosed with MEC on the basis of the initial biopsy. High-grade squamous dysplasia was observed in one patient; however, all four patients showed excellent prognoses without further management. CONCLUSIONS: A conservative approach is recommendable for necrotizing lesions of the palate in young adults to avoid unnecessary treatment. However, careful monitoring is also required due to uncertainty of premalignant potential.

Necrotizing sialometaplasia: a case report of a non-ulcerated histopathological presentation.

A 27-year-old woman presented with the chief complaint of severe pain in the palate region, which had been present for two months. Upon examination, she was found to have a firm, non-ulcerated nodule measuring about 2.5cm at the palatal junction. Incisional biopsy was recommended because the clinical differential diagnosis was mucoepidermoid carcinoma or squamous cell carcinoma. Anatomopathological examination revealed squamous metaplasia of the salivary gland ducts with preservation of the lobular architecture. Immunohistochemistry showed metaplastic ducts with low reactivity for p53 and Ki67, as well as positivity for CK AE1/AE3, CK7, p63, S-100, and SMA. The final diagnosis was necrotizing sialometaplasia. No treatment is required for this disease. Thirty-nine days after biopsy, total remission was observed with no signs of relapse after two years.

Necrotizing Sialometaplasia and Bulimia: A Case Report.

Bulimia is an eating disorder with a great prevalence in young women. Due to its multifactor ethiology, bulimia has systemic consequences. In the literature, necrotising sialometaplasia is seldom associated with bulimia. Its etiopathogenesis is discussed by several authors; nevertheless, the consensus does not consider the relevance of local trauma associated with induced vomiting. A case of necrotising sialomethaplasia, presented with a single hard palatal ulcer in a bulimic woman is described in the present report. The patient did not present significant systemic laboratorial values, nor physical weight variations, which highlights the relevance of performing a complete medical clinical history when diagnosing this rare pathology.

[Immunohistochemical diagnosis of necrotizing sialometaplasia]. / Immunogistokhimicheskaya diagnostika nekroticheskoi sialometaplazii.

The article presents a clinical case of an immunohistochemical study of a rare disease: necrotizing sialometaplasia in the hard palate. Due to the complexity of the differential diagnosis between necrotizing sialometaplasia and squamous cell carcinoma, an immunohistochemical method was used with antibodies to proteins Ki-67, P53, P63 and cytokeratins-7 and Immunohistochemical study established low proliferative activity of glandular cells in excretory ducts and metaplastic squamous epithelium for Ki-67 protein, significant expression of protein P63 was detected both in the ductal epithelium nuclei and in metaplastic areas and expression of the mutant protein P53 was approximately absent. Marked expression of cytokeratin-7 in the ducts cells and weak expression in necrotic acini of the glands and metaplastic epithelium was noted. It was shown that cytokeratin-15 homogeneously stains the peripheral zone of metaplastic epithelium, which is characteristic of a benign lesion. Thus, the panel of antibodies to proteins Ki-67, P53 and cytokeratins-7 and 15 allows to verify necrotizing sialometaplasia.

Necrotizing sialometaplasia of the lacrimal sac mimicking squamous cell carcinoma: Necrotizing dacyocystometaplasia.

INTRODUCTION: Necrotizing sialometaplasia is thought to represent an inflammatory reaction directed against an ischemic insult or local trauma within a glandular tissue and is most commonly observed in the minor salivary glands of the oral mucosa. The importance of this condition arises from the fact that its clinical and histological aspects may raise issues of differential diagnosis with malignant neoplasms. The authors present a case of necrotizing sialometaplasia involving the lacrimal sac simulating a well-differentiated squamous cell carcinoma. CASE: A 52-year-old man presented with epiphora in the left eye after having sustained an orbital blowout fracture during a motor vehicle accident. During subsequent external dacryocystorhinostomy, an abnormal lacrimal sac mucosa was observed and analyzed histologically revealing a well-differentiated squamous cell carcinoma. However, the subsequent biopsies of the lacrimal sac were negative for malignancy; in view of these findings, two pathologists reviewed the first specimen and immunohistochemical staining was performed allowing us to arrive at a diagnosis of necrotizing sialometaplasia. We suggest the term necrotizing dacryocystometaplasia for the involvement at this site. CONCLUSION: Although exceedingly unusual, necrotizing dacryocystomeplasia should be considered in patients presenting with epiphora in the appropriate clinical context. Notably, this condition can be mistaken for a malignant disease, presenting a diagnostic challenge both clinically and histopathologically.

Two rare entities in the same palate lesion: hyalinizing-type clear cell carcinoma and necrotizing sialometaplasia.

Hyalinizing clear cell carcinoma is a low-grade malignant epithelial neoplasm of the salivary glands. The tumor has epithelial cells and lacks myoepithelial cells. Necrotizing sialometaplasia is a benign, self-limiting lesion of the salivary glands. The clinical and histologic features mimic those of mucoepidermoid carcinoma or squamous cell carcinoma. The importance of these entities are the rarity of both of them and their potential to be misdiagnosed as other lesions. 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.

[Necrotizing sialometaplasia--diagnostic difficulties--literature review]. / Necrotizing sialometaplasia--trudnosci diagnostyczne--przeglad pismiennictwa.

Necrotizing sialometaplasia is a benign, self-limiting inflammatory process, which concerns small salivary glands. This kind of lesion is very rare, with difficulties in clinical and histopathological diagnosis. Ulceration is the dominating symptom, which may suggest that it is a malignancy. Lesions usually heal spontaneously.

[Necrotizing sialometaplasia]. / Nekrotisoiva sialometaplasia--suun tuumori ei ollutkaan syöpä.

Necrotizing sialometaplasia is a rare inflammatory condition clinically and histologically resembling a malignant tumor. The lesion is usually present on the palatal mucosa, and heals up without treatment during a couple of months. Differential diagnosis is essential in order to avoid excessive therapy. We describe a case where an oral tumor was not a cancer after all.

A case of necrotizing sialometaplasia involving bilateral parotid glands.

Necrotizing sialometaplasia of the parotid gland is infrequent and can be mistaken as a malignant disease. 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. We report a case of necrotizing sialometaplasia diagnosed after superficial parotidectomy due to bilateral parotid masses in a 69-year old heavy smoking female.

Diagnostic dilemma: our experience with necrotising sialometaplasia.

A man in his 40s presented to our outpatient department with a painful ulcer in the oral cavity for 1 week. After intraoral examination, a single hard palate ulcer, which was non-tender on palpation, was noted. Baseline blood investigations such as haemogram and serological evaluation were within normal limits. Under local anaesthesia, an excisional biopsy was performed. The histopathological examination revealed a reactive necrotising inflammatory process involving minor salivary glands with no cytological atypia. Weekly follow-up was performed and at the end of 4 weeks, complete healing of the lesion had occurred without any further intervention.

Simultaneous presentation of dual pathologies within the oral cavity: an unusual and diagnostically challenging presentation.

Necrotising sialometaplasia (NS) is a rare condition, with a limited scientific evidence base regarding its aetiology and pathophysiology. Diagnosing NS demands extensive investigatory tests. Their accuracy is vital in order to exclude oral malignancy and prevent unwarranted, invasive management.Within Birmingham Dental Hospital, a 22-year-old, South Asian woman presented with generalised pain from the lower right third molar extending to involve the palate, to which the patient's general medical practitioner previously attributed to a viral upper respiratory infection. Clinical examination revealed bilateral erythematous: non-ulcerated, palatal swellings (10 mm x 5 mm) at the greater palatine foramina. Following extensive investigations, the challenging definitive diagnoses of two distinct pathologies were made: non-ulcerative NS and pericoronitis.This case report describes the successful diagnosis and management of non-ulcerating NS, an 'atypical' presentation of a rare condition, that was confounded by a simultaneous episode of pericoronitis - a presentation not previously documented within scientific literature.

Significance of Ki-67 and p53 immunoexpression in the differential diagnosis of oral necrotizing sialometaplasia and squamous cell carcinoma.

Necrotizing sialometaplasia (NS) is a benign condition that usually involves the hard palate and can be mistaken for invasive squamous cell carcinoma (SCC). In this study, we have demonstrated that p53 and Ki-67 staining may assist in the differential diagnosis of NS from SCC. Thirteen cases of NS and 20 cases of oral cavity SCC were randomly selected from our surgical pathology archive from 1992 to 2009. Each case was additionally stained with Ki-67, p53, BCL-2, p16, and epidermal growth factor receptor (EGFR) antibodies. All 13 cases of NS were negatively stained for BCL-2, EGFR, and Ki-67. Three cases (23%) showed weak and focal positive nuclear staining for p53. Two cases (15%) showed positive staining for p16. In 16 well-differentiated SCC cases, p53 was positive in 12 cases (75%); BCL-2, p16, EGFR were positive in 3 cases (18%); and Ki-67 was positive in all cases (100%). In 4 moderately differentiated SCC cases, p53 expression was positive in all cases. Two tumors (50%) had a positive expression of BCL-2. Three cases (75%) had a positive p16 staining, and 1 (25%) had a positive EGFR staining. All cases were positive with high nuclear staining greater than 35% of cells for Ki-67. Ki-67 and p53 showed more intense staining and increased in moderately differentiated SCC comparing with well-differentiated SCC and NS. BCL-2, EGFR, and p16 had the same pattern of staining with the same extent in NS and SCCs. The diagnosis of NS may be difficult and may be supplemented via immunohistochemistry by demonstrating focal or absent p53, low to absent Ki-67 (<10% of cells). Although Ki-67 and p53 staining are generally more intense and are increased in malignancy, these findings may be helpful adjuncts in the differential diagnosis of NS from SCC in appropriate clinical setting.

Necrotizing sialometaplasia: A report of two cases and review of the literature.

Necrotizing sialometaplasia (NS) affects salivary glands, and despite being a benign condition, its clinical and histopathological features sometimes mimic other malignant pathologies of epithelial origin. This article presents two cases of NS and discusses clinicopathological features and the differential diagnosis of this condition. The first case, a 76-year-old woman with a 6-month history of painful oral thrush. Intraoral examination showed an ulcerative lesion located on the hard palate. The clinical hypothesis was squamous cell carcinoma. Second, a 26-year-old man with a 40-days ulcerative lesion on the soft palate. Intraoral examination revealed a reddish ulcer measuring 0.5 cm. Clinical hypothesis was traumatic ulcer. In both cases, a biopsy was performed, and a histopathological diagnosis of NS was established. NS cause is poorly understood, and its clinical features resemble other oral lesions with ulcerative aspects. Thus, dentists must be aware of the clinical features of oral ulcers with more than a 2-week duration without defined etiology.

An unusual case of adenoid cystic carcinoma with hard palate perforation.

Adenoid cystic carcinoma is a malignant tumor which occurs frequently in hard palate associated with minor salivary glands. The lesion generally presents as a painful slow growing mass and it is characterized by recurrences and distant metastasis resulting in a poor prognosis for the patient. This paper reports an atypical adenoid cystic carcinoma with palatal perforation which occurred in a young woman. Initial diagnostic hypothesis were necrotizing sialometaplasia and lues. Although adenoid cystic carcinoma is common in hard palate, cases with palatal perforation are uncommon and may lead to delay in diagnosis and therapy.

Necrotizing sialometaplasia of the parotid gland in a dog.

Necrotizing sialometaplasia (NS) is a self-limiting, benign, ischemic, inflammatory disease that is most often described in the submandibular glands of dogs, with clinical and histologic features that resemble malignancy. Unilateral swelling of the parotid salivary gland in a 7-year-old Cocker Spaniel dog was diagnosed as NS. The dog also had otitis externa on the same side as the parotid gland lesions. The main histologic features were included lobular necrosis of salivary tissue; fibrinoid necrosis of some arteries; marked squamous metaplasia of duct and/or acinar epithelium, with intercellular bridge formation; preservation of salivary lobular morphology; and variable inflammation and fibrosis. Etiologic factors for NS in both humans and animals remain obscure.

A clinical case of necrotizing sialometaplasia and conjunctival hemorrhage.

The first case reported in the literature of a rare disease called necrotizing scialometaplasia (NS), dates back to 1973 when Abrams et al. described the main histological features of this disease. In this article we describe the rare clinical case of a young woman came to our observation for a double ulcer in the middle portion of the hard palate, aching, that histological examination showed compatible with a diagnosis of NS and preceded his appearance a haemorrhagic conjunctival suffusion left. We have provided a complete description of all the investigations in which the patient underwent and its treatment. We have also outlined the major etiological hypotheses of SN, histological features that point to a correct diagnosis, clinical features and prognostic and finally we reflected on the rare and interesting overlap in clinical manifestations palatal and conjunctival those trying to find a possible explanation.

Necrotizing sialometaplasia of the palate associated with angiocentric T-cell lymphoma.

In this article we present 2 cases of necrotizing sialometaplasia (NS) associated with angiocentric lymphoma of the midline. Immunohistochemical analysis confirmed a T-cell origin, and in situ hybridization in one case revealed its relationship to Epstein-Barr virus. These findings suggest that vascular occlusion by the neoplastic cells produces ischemia, which leads to local infarction contributing to the salivary gland lesion. To our knowledge, the association between angiocentric lymphoma and NS has been previously reported in only one instance, and we suggest that this particular type of lymphoma should be added to the list of related conditions for NS.