Necrotizing sialometaplasia: a practical approach to the diagnosis

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.

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

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

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.