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

Abstract

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.

Necrotizing sialometaplasia—A self‐limiting condition which poses a diagnostic dilemma

“…The posterior hard palate is the most common site to be affected by NS and junction of the hard and soft palate being the second most common site. About two‐thirds of the palatal lesions are unilateral; however, midline, bilateral synchronous and metachronous lesions do occur 11,12 . The diagnosis of this lesion is based on the histological criteria proposed by Abrams et al, 1 1973—the presence of ischemic lobular necrosis of seromucous glands, squamous metaplasia of ducts and acini, preservation of intact lobular architecture despite necrosis and inflammation, and accumulation of necrotic debris in the adjacent lobules 1 .…”

Necrotizing Sialometaplasia of the Larynx: A Rare Entity Obscuring a Malignancy

“…The duration of this sequence varies considerably, but the ranges between 4 and 90 days are accepted, and it is uncommon to describe all the stages at any given biopsy specimen. The differential diagnosis is malignancy, principally mucoepidermoid carcinoma [2], but also includes adenosquamous carcinoma [4] or invasive squamous cell carcinoma [6,8]. Nevertheless, as described in the current case, this entity can be associated with a malignancy, which obscures underlying disease diagnosis.…”

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

“…In this study, we included cases in which NSM was the main pathology, excluding any cases associated with malignancies. As described in the literature, NSM-like morphologic changes can be seen in the periphery of the cancer-involved salivary glands, which raises suspicion that NSM might be a precancerous lesion [ 9 ]. We also discovered some cases of salivary gland carcinoma accompanied by squamous metaplasia of the surrounding ductal epithelia (Fig.…”

“…Although the clinical course of NSM is self-limiting, the premalignant potential of NSM has long been pointed out. Association with other malignancies, such as epithelial-myoepithelial carcinoma or adenoid cystic carcinoma, and even malignant lymphoma have been reported to coexist with NSM [ 9 , 19 – 22 ]. There are still controversial issues regarding the application of strict criteria for NSM in these lesions due to the possibility of overdiagnosing NSM, as shown in some previous reports.…”