Necrotizing sialometaplasia: report of five cases.

The natural history of necrotizing sialometaplasia as a self-healing process makes it essential for the surgeon and the pathologist to distinguish this entity from carcinoma. Seventeen of the 39 early cases were initially misdiagnosed as malignant. Occasionally, residual glands can be trapped in mucous lakes, giving the appearance of mucoepidermoid carcinoma. An awareness of the entity and adequate clinicopathologic correlation should lead to a correct diagnosis. A limited biopsy specimen may create a problem in diagnosis and may necessitate more adequate tissue for proper evaluation. Necrotizing sialometaplasia can present as an ulceration or a swelling beneath the mucosa, either of which can be painless or painful with radiation of pain to the ear, eye, or pharynx. Lesions presenting as a swelling will either convert to an ulceration or heal spontaneously, never forming an ulcer. The most commonly involved area is the palate (79 percent), but any area where glandular oral mucosa is present can be involved. The male-to-female ratio is 3:1, and it shows no predilection for race. The etiology of the disease remains unknown, but it may be associated with tobacco, alcohol, the use of dentures, and local trauma. Most investigators seem to favor an ischemic basis. Lesions heal spontaneously without treatment, and the only invasive procedure required is a biopsy.