Early-Stage Non-Ulcerated Necrotizing Sialometaplasia Mimicking Malignancy in a Pediatric Patient: A Case Report

The primary structures affected by pathological changes in the palate are the numerous minor salivary glands located within the hard palate. Among the most significant alterations are neoplastic and inflammatory conditions. A well-known inflammatory condition, necrotizing sialometaplasia (NS), typically involves the minor salivary glands of the hard palate. Clinically, NS is usually described as a nodule that develops into a central ulcer approximately 1 cm in diameter. Although ischemic events are the most commonly recognized triggers, other potential causes include local trauma, substance abuse and eating disorders [1,2]. It is important to emphasize that ulcerated NS may mimic mucoepidermoid carcinoma the most common malignant salivary gland tumour and its clinical features can resemble those of other malignant salivary gland tumours [3]. In rare instances, NS may present as a non-ulcerated lesion. In such cases, when a bluish-red swelling is observed, malignancy should also be considered in the differential diagnosis [1,4,5]. Other granulomatous conditions that can resemble NS include deep fungal infections and syphilitic gum disease [6].

Aim

The purpose of this report is to present the clinical and histological characteristics of a case of non-ulcerated necrotizing sialometaplasia (NS), described as an eroded area beginning to develop ulceration and to emphasize the importance of including malignant salivary gland tumours in the differential diagnosis.

A 9-year-old girl, accompanied by her father, presented with acute, radiating pain on the right side of her jaw lasting approximately three minutes. Her medical history included multiple episodes of sublingual aphthous ulcers. At presentation, she did not report any persistent painful trigger points. Clinical examination revealed a crossbite, attributed to a slight leftward deviation of the mandible.

During a follow-up appointment, the patient reported similar pain episodes. She was prescribed antibiotics (amoxicillin 10 mg/kg) and analgesics (paracetamol 15 mg/kg). Intraoral examination revealed pain and swelling across the palatal mucosa, along with signs of pericoronitis around teeth #16 and #17 as shown in Figure 1.

Figure 1: Clinical image showing a discrete, elevated, erythematous area on the right hard palate, indicative of a non-ulcerated NS lesion.

CBCT imaging showed significant thickening of the maxillary sinus mucosa, with the mucosa extending superiorly and nearly filling the antrum (Figure 2). Based on the suspicion of a dentoalveolar abscess, fungal infection or maxillary sinus pathology, hospitalization was recommended.

Figure 2(a,b): Cone Beam Computed Tomography imaging revealed pronounced mucosal thickening in the maxillary sinus, with the mucosa extending upward and almost completely occupying the antrum.

The patient was referred for otorhinolaryngology (ORL) evaluation, including a CT scan of the facial bones and a biopsy of the antral lesion (Figure 3). She was admitted for intravenous treatment and underwent an exploration and biopsy under general anaesthesia. A biopsy was obtained and referred to the pathologist for examination.

Figure 3(a,b,c): (a) Coronal view. (b) Axial view. (c) Sagittal view of computed tomography scan shows mucosal thickening of the right maxillary sinus, with the mucosa extending superiorly and nearly filling the antrum.

The lesion showed progressive healing and achieved complete resolution within a few days following the biopsy (Figure 4).

Figure 4: (A) Final clinical image showing complete healing a few days after the biopsy procedure. (B) Development of a periapical infection.

One week later, she returned with a complaint of a periapical abscess associated with the upper right second primary molar #55 as seen in (Figure 5).

Figure 5: Development of a periapical infection related to the upper right second primary molar tooth #55.

A 5-day course of amoxicillin (10 mg/kg) was prescribed, followed by extraction of the affected tooth (Figure 6).