Necrotising sialometaplasia in the floor of mouth

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.