A 47-year-old male visited a general dentist for evaluation of an ulcerated lesion on the hard palate.
Joen Iannucci Haring, DDS, MS
The patient was aware of the ulceration on his palate and stated that it had been present for at least one month, perhaps longer. The lesion was described as initially painful, but now relatively painless. When questioned about tobacco and alcohol use, the patient stated that he smokes 10 to 15 cigarettes per day and drinks occasionally. When questioned about his last medical visit, the patient stated that he last saw a physician several months earlier for treatment of viral pneumonia.
The patient appeared to be in a good state of health and denied any history of serious illness, heart problems, or high blood pressure. A review of the medical history revealed an allergy to penicillin, an appendectomy and surgery for a compound fracture of the femur. At the time of the dental appointment, the patient was not taking medications of any kind.
The patient`s blood pressure, pulse rate, and temperature were all found to be within normal limits. No enlarged lymph nodes in the head and neck region were detected upon palpation. Physical examination of the head and neck region revealed no unusual findings. Intraoral examination revealed an ulceration on the posterior hard palate measuring more than 1.0 centimeter in diameter (see photo). Further examination revealed no other lesions present.
Based on the clinical information presented, which of the following is the most likely clinical diagnosis?
* pleomorphic adenoma
* mucoepidermoid carcinoma
* squamous cell carcinoma
* necrotizing sialometaplasia
Necrotizing sialometaplasia is a benign, uncommon condition of the salivary glands. Although the definitive cause is uncertain, most investigators believe that this condition is the result of ischemia of salivary gland tissue which results in tissue infarction, necrosis, and ulceration.
A number of predisposing factors have been suggested and include the following: traumatic injury, dental injections, ill-fitting dentures, previous surgery, tumor development, and upper respiratory infections. These predisposing factors are believed to play a role in compromising the blood supply to the involved glands, resulting in ischemia and necrosis.
Necrotizing sialometaplasia is typically seen in adults and the average age of the onset is 46. Necrotizing sialometaplasia affects males twice as often as females. This condition most often involves the minor salivary glands of the hard and soft palates. More than 75 percent of all cases occur on the posterior hard palate. Approximately two-thirds of these cases are unilateral in presentation, with the remaining one-third presenting as bilateral or midline lesions. Although necrotizing sialometaplasia is occasionally seen in other locations involving both minor and major salivary glands, the submandibular and sublingual glands are rarely affected.
The initial presentation of necrotizing sialometaplasia is that of a non-ulcerated swelling associated with pain and paresthesia. Within two to three weeks, an ulceration occurs as the result of the sloughing out of necrotic tissue. A patient may report that "a part of my palate fell out.O At this point, the pain is often reported to subside. The ulceration may range in size from one to five centimeters in diameter.
Diagnosis and treatment
A number of oral lesions should be included in the differential diagnosis for necrotizing sialometaplasia. Squamous cell carcinoma, as well as a number of benign and malignant salivary gland tumors, may be clinically confused with this lesion. The diagnosis of necrotizing sialometaplasia is made based on a biopsy and histologic examination of the lesion.
It is important to note that necrotizing sialometaplasia mimics a malignant process, both clinically and microscopically. Consequently, a definitive diagnosis is made based on histologic examination. Once the diagnosis has been established, no specific treatment is required. This lesion typically heals over a period of five to six weeks, but may take as long as 12 weeks to resolve.
Joen Iannucci Haring, DDS, MS, is an associate professor of clinical dentistry, Section of Primary Care, The Ohio State University College of Dentistry.