Experimental study on necrotizing sialometaplasia of the palate in rats. Role of local anesthetic injections

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 can hide the presence of salivary gland tumors: A case series

OBJECTIVE

Necrotizing sialometaplasia (NS) is an uncommon benign process which affects minor and, more rarely, major salivary glands. While self-limiting, the condition might be clinically and histologically mistaken for malignancy. Furthermore, NS may accompany neoplasms. The aim of this paper was to report a series of Italian patients affected by NS associated with an unusual high presence of neoplasms of minor and major salivary glands.

STUDY DESIGN

Clinical and histological features of twelve patients with NS were retrospectively evaluated.

RESULTS

Eight patients presented NS of the minor salivary glands of the palate, and two of them had associated neoplasms (pleomorphic adenoma and adenoid cystic carcinoma) at the same site. Four patients had NS of the parotid gland associated with a history of fine-needle aspiration biopsy performed to diagnose parotid neoplasms. These were epithelial-myoepithelial carcinoma, adenoid cystic carcinoma, Warthin's tumor, and oncocytoma, respectively.

CONCLUSION

Tumors of minor and major salivary glands might be associated with NS more frequently than previously reported. While NS of the parotid is generally the result of invasive diagnostic procedure and is detected after the excision of the tumor, NS of the minor salivary glands may obscure an underlying neoplasm, resulting in delays in referral or treatment.

Feline necrotising sialometaplasia: A report of two cases

Unilateral swelling of submandibular salivary gland in two cats was diagnosed as necrotising sialometaplasia. Histological features that differentiate the disease from other salivary gland lesions, particularly neoplasia are: lobular necrosis of salivary tissue; squamous metaplasia conforming to duct and/or acinar outlines; preservation of salivary lobular morphology; and variable inflammation and granulation tissue.

Contralateral recurrence of necrotizing sialometaplasia of the hard palate after five months: a case report

Necrotizing sialometaplasia usually heals within 4 to 10 weeks with conservative treatment, and rarely recurs. When necrotizing sialometaplasia is present on the hard palate it may occur unilaterally or bilaterally. In this case, necrotizing ulceration occurred on the left hard palate of a 36-year-old woman after root canal treatment of the upper left first premolar under local anesthesia. After only saline irrigation the defect of the lesion completely healed and filled with soft tissue. After 5 months, however, a similar focal necrosis was found on the contralateral hard palate without any dental treatment having been performed on that side and progressed in similar fashion as the former lesion. We conducted an incisional biopsy and obtained a final pathological diagnosis for the palatal mass of necrotizing sialometaplasia. At the 3-year follow-up, the patient's oral mucosa of the hard palate was normal, without any signs and symptoms of the condition. We report a case of a second occurrence of necrotizing sialometaplasia on the contralateral side from the first, with a time lapse between the first and second occurrence.

Spontaneous necrotizing sialometaplasia of the submandibular salivary gland in a Beagle dog

A single mass was found on the left submandibular salivary gland at necropsy of a 15-month-old male commercially bred laboratory Beagle dog from a control dose group from a repeat toxicity study. Microscopically, the mass was composed of a well-demarcated area of coagulative necrosis surrounded and separated from the normal salivary gland tissue by a thick fibrovascular capsule. Necrosis was admixed with areas of hemorrhage, fibrin, edema, fibrinoid necrosis of the vascular tunica media, and thrombosis of small and large vessels. Within the necrotic tissue, there was marked ductal hyperplasia, and squamous metaplasia of duct and acinar epithelium. The mass was diagnosed as necrotizing sialometaplasia of the submandibular gland. Hyperplastic ductal elements and squamous metaplasia can be mistaken microscopically with squamous cell carcinoma. Therefore, pathologists should be aware of this lesion as to avoid errors in the diagnosis of this benign pathologic condition.

Necrotizing sialometaplasia of tongue

Necrotizing sialometaplasia, is a benign inflammatory lesion primarily involving the minor salivary glands of the hard palate. The lesion often presents itself as a deep-seated palatal ulcer with clinical and histological features similar to those of a malignant neoplasm. Here we report a case of necrotizing sialometaplasia in a 40-year-old female, present on the lateral border of the tongue, mimicking squamous cell carcinoma, clinically. A correct diagnosis to avoid mutilant surgical treatments is essential, considering that it is a self-limiting disease.

A perspective of comparative salivary and breast pathology. Part I: microstructural aspects, adaptations and cellular events

This is the first part of a review comparing the pathology of salivary and mammary glands. Here, less obvious similarities and differences in functional histology and their influences on pathology are examined with emphasis on myoepithelial cells, stromal components, analogues of mucosa-associated lymphoid tissue, steroid receptors, and intraparenchymal cells of monocytic lineage. Particular cell phenotypes (oncocytic, apocrine, neuroendocrine and clear) are critically evaluated and responses to atrophy, infarction and fine-needle aspiration biopsy procedures are highlighted together with aspects of metaplasia, regeneration, ageing and microcalcification. Areas of controversy or uncertainty which may benefit from further investigations are also discussed.

Necrotizing sialometaplasia in a patient with an eating disorder: palatal ulcer accompanied by dental erosion due to binge-purging

This report describes a case of necrotizing sialometaplasia (NS) accompanied by significant dental erosion of the maxillary teeth of the palatal surfaces owing to chronic self-induced vomiting. This observation contributed to the determination of an immediate and appropriate provisional diagnosis of NS in a patient with an eating disorder, which subsequently was confirmed histopathologically as NS. The diagnostic challenges presented by NS associated with eating disorders and its management are discussed.

The clinical, histologic, and treatment spectrum in necrotizing sialometaplasia

OBJECTIVES

The aim of this report was the clinical and histologic characterization of necrotizing sialometaplasia.

STUDY DESIGN

We performed a retrospective case series analysis.

RESULTS

The study included 4 women 29-71 years old. Possible contributing factors (drugs, alcohol abuse, bulimia, smoking, and pancreatic cancer) were identified. Patients presented with unilateral or bilateral rapidly progressing painful palatal ulcers. Necrotic salivary glands and inflammation were universal microscopic features; ductal metaplasia was present in only 1 case. Thrombosis and heavy fungal and bacterial overgrowth were observed in 1 case. In 3 of the cases the lesions healed within 4-6 weeks under conservative supportive care, whereas in 1 case persistent enlargement up to 25 mm diameter was observed. Surgical debridement combined with a palatal guard resulted in complete healing within 12 weeks.

CONCLUSIONS

Significant variations may be observed in both clinical and microscopic manifestations of necrotizing sialometaplasia. Although this disease is considered to be self-limiting in the majority of cases, surgical intervention can be considered in unusually large cases.

Necrotizing sialometaplasia in two patients with bulimia and chronic vomiting

The purpose of this report was to present two unusual cases of necrotizing sialometaplasia of the hard palate, in which the patients were suffering from bulimia and chronic self-induced vomiting. It emphasizes the importance of confirming the diagnosis by incisional biopsy and discusses local mucosal trauma as a possible etiologic factor.