Case report. MRI findings of necrotizing sialometaplasia

Diagnostic work-up in obstructive and inflammatory salivary gland disorders

Inflammatory and obstructive disorders of the salivary glands are caused by very different pathological conditions affecting the gland tissue and/or the excretory system. The clinical setting is essential to address the appropriate diagnostic imaging work-up. According to history and physical examination, four main clinical scenarios can be recognised: (1) acute generalised swelling of major salivary glands; (2) acute swelling of a single major salivary gland; (3) chronic generalised swelling of major salivary glands, associated or not with "dry mouth"; (4) chronic or prolonged swelling of a single major salivary gland. The algorithm for imaging salivary glands depends on the scenario with which the patient presents to the clinician. Imaging is essential to confirm clinical diagnosis, define the extent of the disease and identify complications. Imaging techniques include ultrasound (US), computed tomography (CT) and magnetic resonance (MR) with MR sialography.

Imaging findings of necrotizing sialometaplasia of the parotid gland: case report and literature review

Although necrotizing sialometaplasia (NS) of the parotid gland is rare and occasionally presents as a lesion that mimics a malignant tumour, imaging findings in cases of NS have been rarely reported. We describe here a case of NS in which there was an increasing lesion manifesting overnight on the parotid gland in an 83-year-old male. We also investigated the use of pre-operative imaging based on previous reports and discuss the importance of these images in helping to guard against overzealous treatment. It is critically important to closely examine whether there are aspects of NS, such as the present case, in pre-operative MRI findings that can be useful in proper diagnosis and treatment.

Benign or malignant? Case report

INTRODUCTION

Necrotizing sialometoplasia (NS) is a disease in which the clinical and sometimes even histological features can be confused with those of a malignant tumor, but which is in fact a self-limited inflammatory lesion of the salivary glands.

CASE REPORT

The authors present a case study of a 43-year-old female patient who came to the ENT Emergency Department with a painful ulcerated lesion of the hard palate. The lesion was 8 days old and had appeared after an abdominoplasty. Given the clinical need to rule out a malignant neoplasm, a biopsy was performed: the histological result was NS.

DISCUSSION/CONCLUSION

The authors make a literature review and stress the importance of differentiating between NS and salivary gland neoplasia. Histology is essential in case of ulcerated neoformation of the oral cavity, to adapt treatment, avoiding unsuitable approaches.

Significance of Ki-67 and p53 immunoexpression in the differential diagnosis of oral necrotizing sialometaplasia and squamous cell carcinoma

Necrotizing sialometaplasia (NS) is a benign condition that usually involves the hard palate and can be mistaken for invasive squamous cell carcinoma (SCC). In this study, we have demonstrated that p53 and Ki-67 staining may assist in the differential diagnosis of NS from SCC. Thirteen cases of NS and 20 cases of oral cavity SCC were randomly selected from our surgical pathology archive from 1992 to 2009. Each case was additionally stained with Ki-67, p53, BCL-2, p16, and epidermal growth factor receptor (EGFR) antibodies. All 13 cases of NS were negatively stained for BCL-2, EGFR, and Ki-67. Three cases (23%) showed weak and focal positive nuclear staining for p53. Two cases (15%) showed positive staining for p16. In 16 well-differentiated SCC cases, p53 was positive in 12 cases (75%); BCL-2, p16, EGFR were positive in 3 cases (18%); and Ki-67 was positive in all cases (100%). In 4 moderately differentiated SCC cases, p53 expression was positive in all cases. Two tumors (50%) had a positive expression of BCL-2. Three cases (75%) had a positive p16 staining, and 1 (25%) had a positive EGFR staining. All cases were positive with high nuclear staining greater than 35% of cells for Ki-67. Ki-67 and p53 showed more intense staining and increased in moderately differentiated SCC comparing with well-differentiated SCC and NS. BCL-2, EGFR, and p16 had the same pattern of staining with the same extent in NS and SCCs. The diagnosis of NS may be difficult and may be supplemented via immunohistochemistry by demonstrating focal or absent p53, low to absent Ki-67 (<10% of cells). Although Ki-67 and p53 staining are generally more intense and are increased in malignancy, these findings may be helpful adjuncts in the differential diagnosis of NS from SCC in appropriate clinical setting.

CT findings of necrotizing sialometaplasia

An otherwise healthy 56-year-old Caucasian female was referred to the radiology department because of an ulceration of her palatal mucosa. Clinically the lesion was suspected to be malignant and a multislice CT examination of the head and neck region was performed. This revealed an ulcer-like cavity with no tumour-like contrast enhancement. No relevant bone changes or suspicious lymph nodes of the neck were detected. Based on the multislice CT findings, necrotizing sialometaplasia was suspected and the diagnosis was verified histopathologically. This report describes the CT findings of necrotizing sialometaplasia at the ulceration stage.

Necrotizing sialometaplasia: a practical approach to the diagnosis

CONTEXT

Necrotizing sialometaplasia is a benign, self-limited lesion of both major and minor salivary glands, although more commonly the latter. It can represent a diagnostic dilemma and may be mistaken for a malignant neoplasm, such as mucoepidermoid carcinoma, as well as invasive squamous cell carcinoma. A major causal relationship has been ascribed to ischemia. Bulimia, an eating disorder with increasing prevalence in our society, may also be an underlying underreported cause.

OBJECTIVE

To discuss the potential pathogenesis, diagnostic pitfalls, and the application of immunohistochemistry as an aid in the diagnosis of necrotizing sialometaplasia.

DATA SOURCES

This report uses a previously published case history for illustrative purposes and a review of the current literature.

CONCLUSIONS

The diagnosis of necrotizing sialometaplasia may be difficult and is reliant upon a well-oriented biopsy section and a complete clinical history. Diagnosis may be further supplemented via immunohistochemistry, demonstrating focal to absent immunoreactivity for p53, low immunoreactivity for MIB1 (Ki-67), and the presence of 4A4/p63- and calponin-positive myoepithelial cells. Interpreted in context collectively, these findings may be helpful adjuncts in the diagnosis of necrotizing sialometaplasia; nonetheless, to date, hematoxylin-eosin staining remains the gold standard.

Necrotizing sialometaplasia accompanied by adenoid cystic carcinoma on the soft palate

Necrotizing Sialometaplasia (NS) is a benign, self-limiting inflammatory disease of the mucus-secreting glands, and this illness mainly involves the minor salivary glands. The significance of NS resides in its clinical and histopathological resemblance to malignancy. We present here a case of necrotizing sialometaplasia on the soft palate, and this was accompanied by adenoid cystic carcinoma. We report here on this case to draw attention to the difficulty for deciding the extent of resecting a malignancy, and especially when the malignancy is simultaneously accompanied by necrotizing sialometaplasia.