|Year : 2014 | Volume
| Issue : 3 | Page : 355-358
Necrotizing sialometaplasia of the palate: A case report
Ashwarya Trivedi, Mysore K Sunil, Sonam Gupta, Shaveta Garg
Department of Oral Medicine and Radiology, Guru Nanak Dev Dental College and Research Institute, Sunam, Punjab, India
|Date of Submission||26-Jun-2014|
|Date of Acceptance||06-Nov-2014|
|Date of Web Publication||19-Nov-2014|
PG student, Department of Oral Medicine and Radiology, Guru Nanak Dev Dental College and Research Institute, Bathinda-Patiala Road, Sunam - 148 028, Punjab
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Necrotizing sialometaplasia is a benign, self-limiting, reactive inflammatory disorder of the salivary tissue, which mimics malignancy both clinically and histopathologically. The etiology is unknown, although it most likely represents a local ischemic event, infectious process or perhaps an immune response to an unknown allergen. A case of necrotizing sialometaplasia of the palate in a 40-year-old male patient is presented. Histopathological examination is necessary for the diagnosis of necrotizing sialometaplasia because the clinical features of this condition can mimic other diseases, particularly malignant neoplasms.
Keywords: Minor, necrotizing, palate, saliva, salivary glands, sialometaplasia
|How to cite this article:|
Trivedi A, Sunil MK, Gupta S, Garg S. Necrotizing sialometaplasia of the palate: A case report
. J Indian Acad Oral Med Radiol 2014;26:355-8
|How to cite this URL:|
Trivedi A, Sunil MK, Gupta S, Garg S. Necrotizing sialometaplasia of the palate: A case report
. J Indian Acad Oral Med Radiol [serial online] 2014 [cited 2021 Dec 7];26:355-8. Available from: https://www.jiaomr.in/text.asp?2014/26/3/355/145032
| Introduction|| |
Necrotizing sialometaplasia (NS) was first described by Abrams and Melrose in 1973.  Necrotizing sialometaplasia is a necrotizing inflammatory process that largely involves the minor salivary glands and the major salivary glands in up to 10% of the cases.  It may occur in all the regions where salivary gland tissue is found, such as, the nasal cavity sinuses, lower lip, tongue, cheek, retromolar pad, soft palate, and larynx; however, it occurs most commonly in the palate.  Here we report a case of a 40-year-old male patient corresponding to the clinical and histopathological features of NS in the mid-palatal region.
| Case Report|| |
A 40-year-old male patient, who was a driver by occupation, reported to the department with a chief complaint of pain in the palatal region since 15 days. The history of present illness revealed that the pain was severe, intermittent, sudden in onset, and radiated to the left temporal region. There was a history of swelling in the same region 10-15 days back, which was initially small in size and gradually increased to the present size. There was also a history of pus discharge from the swelling since eight to ten days. There was no history of trauma, paresthesia or fever. The patient gave a history of extraction of the upper front teeth six to seven months back, as the teeth were mobile. The past medical history revealed no systemic illness. The personal history revealed that the patient was vegetarian in diet and there was no history of any deleterious habit like smoking, tobacco, betel nut chewing, alcohol or the like.
Extraoral examination revealed no abnormality. Intraoral examination revealed a swelling in the hard palate, which was approximately 3 × 3 cm, extending posteriorly from the palatal mucosa behind the anterior teeth, up to the junction of the hard and soft palate. It extended mediolaterally from the 13, 14, 15, and 16 teeth region on the patient's right side to the 23, 24, 25, and 26 teeth region on the left side, crossing the mid palatine raphe. The surface of the swelling was lobulated. The overlying mucosa was erythematous when compared with the surrounding mucosa. There was a palatal perforation in the midpalatal region. On palpation, the swelling was soft-to-firm in consistency, non-compressible, non-reducible, and tender. There was exudation of pus from the opening [Figure 1]. Teeth numbers 11, 12, 21, and 22 were missing and generalized calculus and stains were present.
|Figure 1: Intraoral picture showing swelling with perforation in the mid-palatal region|
Click here to view
With the above clinical findings, a provisional diagnosis of generalized chronic periodontitis with suppurative osteomyelitis was made and differential diagnoses of deep mycotic infection, squamous cell carcinoma, mucoepidermoid carcinoma, and midline lethal granuloma were considered.
Intraoral periapical radiographs (IOPA) were taken, which showed vertical loss of alveolar bone in relation to 14, 15, 16, and 17, and horizontal loss of alveolar bone in relation to 26, 27, and 28 [Figure 2]a and b. A maxillary cross-sectional occlusal radiograph was taken, which revealed normal anatomic landmarks and missing teeth, namely, 11, 12, 21, and 22. A diffuse rarefied area was seen in the anterior mid-palatal region [Figure 3].
|Figure 2: (a) IOPA radiograph of 14, 15, 16, and 17; (b) IOPA radiograph of 26, 27, and 28|
Click here to view
|Figure 3: Occlusal radiograph showing a diffuse rarefied area in the anterior mid-palatal region|
Click here to view
The patient was subjected to a complete hemogram, which revealed normal values except a raised erythrocyte sedimentation rate (ESR), which was 22 mm/hour. A culture test was advised, to rule out fungal infection, which gave a negative result for fungal growth. Under local anesthesia, an incisional biopsy was performed and the specimen was sent for histopathological examination. The histopathological examination revealed areas of necrosis and inflammatory granulation tissue along with scattered lymphoid cells. There was a diffuse mixed inflammatory infiltrate, consisting of neutrophils, plasma cells, occasional eosinophils, foamy macrophages, and extensive squamous metaplasia of the salivary ducts and acini, with prominent stromal mucin. No evidence of granulomatous pathology or malignancy was found in the biopsy tissue [Figure 4]. A final diagnosis of necrotizing sialometaplasia was made. The patient was advised symptomatic treatment and referred to the Department of Oral Surgery for follow-up.
| Discussion|| |
Necrotizing sialometaplasia is a self-limiting, variably ulcerated, benign process affecting the minor salivary glands. The most commonly proposed and generally accepted etiology for NS relates to ischemia.  The most widely accepted theory explaining the etiology is ischemia of the blood vessels, leading to infarction of the gland tissues.  The Armed Forces Institute of Pathology has reported that 25 of 69 NS cases have occurred following a surgical procedure. Other predisposing factors include traumatic injuries, such as a dental injection, blunt force trauma, denture wear, alcohol and tobacco use, and upper respiratory infections.  In the case reported here, the cause of the lesion could not be identified. In 1996, Shigematsu et al. found a relationship between the repeated application of local anesthesia to a rat palate and histological changes similar to those observed in NS. 
Necrotizing sialometaplasia shows a male predeliction, with a male-to-female ratio of 2:1. According to literature NS is diagnosed at an average age of 46 years. In some cases, it may be seen in much younger individuals, as mentioned in one case report, describing NS in a two-year-old girl.  In the present case, the disease was diagnosed in a 40-year-old male patient.
Clinically, necrotizing sialometaplasia is characterized by a seemingly spontaneous presentation, most commonly at the junction of the hard and soft palates. Early in its evolution, the patient may note a tender swelling. Subsequently, the mucosa breaks down as a sharply demarcated deep ulcer with a yellowish-gray lobular base. In the palate, the lesion may be unilateral or bilateral; the diameter of an individual lesion ranges from 1 to 3 cm. Most patients indicate mild complaints of tenderness or dull pain. Healing is generally slow and protracted, ranging from six to ten weeks.  In the present case, the swelling was present on the hard palate with a perforation and the swelling was tender to palpation. Deviating from the common, the present patient complained of pain, which was severe, intermittent, sudden in onset, and radiating to the left temporal region. The severity of the pain could be related to the severity of the lesion in the present case. Necrotizing sialometaplasia characteristically shows a deep ulcer. Hence, the differential diagnosis should include granulomatous diseases. Also opportunistic infections in immunocompromised patients may imitate NS.  In the present case, a culture test was advised to rule out fungal infection, which revealed negative results.
The histopathological appearance of NS shows coagulation necrosis of the glandular acini, an inflammatory response, and pseudoepitheliomatous hyperplasia of the overlying epithelium, with preservation of the lobular structure of the gland.  On the basis of the histopathology, Anneroth and Hansen et al. have classified NS into five stages: Infarction, sequestration, ulceration, the reparative stage, and the healed stage. During infarction, the glandular acini undergo necrosis, resulting in the formation of an ulcer. As the lesion heals there is proliferation of the overlying epithelium, which is seen microscopically as pseudoepitheliomatous hyperplasia. No sequestration occurs if there is limited infarction. As healing takes place, there is phagocytic activity of the histiocytes and neutrophils, and appearance of granulation tissue. , On the basis of the histopathological findings, the present case appeared to be in the ulcerative stage at the time the patient reported to us.
The classical histopathological differential diagnosis of NS includes squamous cell and mucoepidermoid carcinomas. However, there are certain benign lesions requiring differentiation from NS. Necrotizing sialometaplasia-like changes, without a lobular configuration, have been reported in herpetic tracheitis following intubation and have been called necrotizing squamous metaplasia. Another rare benign disease that has to be taken into account in the differential diagnosis of NS is a disorder termed subacute necrotizing sialadenitis.  Subacute necrotizing sialadenitis (SANS) is a self-limiting inflammatory lesion of the minor salivary glands, of unknown cause. There is a varied opinion by authors on this entity. Although some consider it to be a distinct entity, others consider it as a variant of NS.  According to Lombardi et al. (2003), 22 cases of SANS have been reported in literature (up to 2003); most of them in the palatal salivary glands. They have reported that SANS is more (77%) commonly seen in young men. The clinical features include a unilateral, erythematous, non-ulcerated swelling, which is mostly painful. Most often the posterior hard palate and rarely the soft palate is involved. The lesion is also self-limiting, which heals in a few days or weeks. 
The management of NS includes symptomatic treatment and the lesions undergo spontaneous healing within two to three months. Surgical excision is not necessary. The recurrence rate of NS is low. Reassessment of the lesions that fail to resolve is important. 
| Conclusion|| |
As the clinical appearance of necrotizing sialometaplasia can imitate other diseases, particularly malignant neoplasms, histopathological examination is necessary to confirm its diagnosis. The histopathological findings also suggest the stage of the lesion.
| References|| |
|1.||Keogh PV, O'Regan E, Toner M, Flint S. Necrotizing sialometaplasia: An unusual bilateral presentation associated with antecedent anaesthesia and lack of response to intralesional steroids. Case report and review of the literature. Br Dent J 2004;196:79-81. |
|2.||Farina D, Gavazzi E, Avigo C, Borghesi A, Maroldi R. Case report. MRI findings of necrotizing sialometaplasia. Br J Radiol 2008;81:e173-5. |
|3.||Carlson DL. Necrotizing sialometaplasia: A practical approach to the diagnosis. Arch Pathol Lab Med 2009;133:692-8. |
|4.||Randhawa T, Varghese I, Shameena P, Sudha S, Nair RG. Necrotizing sialometaplasia of tongue. J Oral Maxillofac Pathol 2009;13:35-7. |
|5.||Bascones-Martínez A, Muñoz-Corcuera M, Cerero-Lapiedra R, Bascones-Ilundáin J, Esparza-Gómez G. Case report of necrotizing sialometaplasia. Med Oral Patol Oral Cir Bucal 2011;16:e700-3. |
|6.||Ylikontiola L, Siponen M, Salo T, Sándor GK. Sialometaplasia of the soft palate in a 2-year-old girl. J Can Dent Assoc 2007;73:333-6. |
|7.||Oliveira Alves MG, Kitakawa D, Carvalho YR, Guimarães Cabral LA, Almeida JD. Necrotizing sialometaplasia as a cause of a non-ulcerated nodule in the hard palate: A case report. J Med Case Rep 2011;5:406. |
|8.||Pabuççuoðlu U, Özkara E, Sarýoðlu S. Necrotizing sialometaplasia. Report of five cases including uncommon localizations. Turk J Med Sci 2002;32:355-9. |
|9.||Newland J. Bilateral presentation of necrotizing sialometaplasia - A case report. Dent Update 2007;34:586-8. |
|10.||Lombardi T, Samson J, Küffer R. Subacute necrotizing sialadenitis: A form of necrotizing sialometaplasia? Arch Otolaryngol Head Neck Surg 2003;129:972-5. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4]