Answer: Necrotizing sialometaplasia

Histology: The biopsy shows squamous mucosa with inflamed granulation tissue, reactive epithelial changes and small minor salivary glands with squamous metaplasia and central necrosis. The lobular architecture of the glands is retained which is best seen on low power magnification.

Discussion: Necrotizing sialometaplasia is a reactive condition that usually involves minor salivary glands often in areas that were radiated. The disease usually presents as an ulcerating lesion on the hard palate but also can occur at other sites in the head neck region. Histologically, it is characterized by vascular proliferation, inflammation, and squamous metaplasia of the acini and adjacent ducts with foci of central necrosis. The lobular architecture, however, is preserved and is the most helpful feature to distinguish necrotizing sialometaplasia form squamous cell carcinoma.