ODA Feature: Palatal Swelling, Pain, and Central Ulcer After Final Exam Week

Palatal swelling, pain, and central ulcer after final exam week

By: Ronnie Faram, DDS, Clinical Assistant Professor and Division Head, Oral Pathology OU College of Dentistry

A 25-year-old female student who had recently completed a stressful final exams week noticed a localized, red spot on her palate while brushing her teeth. She reported no pain at first, by the next day the area had become more erythematous and uncomfortable. She presented to Oral Pathology at the University of Oklahoma College of Dentistry as recommended by ENT. She reported the lesion was “fairly painful.” Her dental evaluation was excellent, negative for caries and periodontal disease. She had no recollection of trauma and no signs or symptoms of infection or recent illness. She was healthy with a non-contributory medical history. She was not taking any medications and had no reported illicit drug use. The clinical photos reveal a quickly progressing, erythematous, slightly swollen nodular area in the midline of the hard palate. The patient had taken a picture on the first day of discomfort and then presented the following day with a slightly larger erythematous area. The central portion of the lesion was even a darker red. (See photos 1 and 2)

The next important clinical questions were:

What is the differential diagnosis for the lesion? What will the working diagnosis be? What is the next step in treatment management for this patient?

Potential differential diagnoses:

Palatal abscess Recurrent herpes simplex infection Salivary gland tumor Median palatal (palatine) cyst Squamous cell carcinoma Necrotizing sialometaplasia The palatal abscess is a relatively common condition in the oral cavity compared to the other diagnoses listed in the differential. However, abscesses are usually associated with a non-vital tooth in which an acute or chronic apical periodontitis progresses to an abscess or an acute inflammatory response in the region. Although most abscesses drain to the thinner buccal cortical plate (1). The maxillary molar’s palatal roots can provide a channel for infection and abscess formation on the palatal surface. The fact that the patient had no source of infection: no decay, vital teeth, excellent dental health, and no periodontal disease significantly reduced suspicion of this common acutely painful abscess. Recurrent herpes simplex virus infection is a common condition that usually presents with a prodrome leading to “crops” of vesicles (numerous and small) that quickly rupture and form coalescing ulcers on the mucocutaneous junction of the lip. However, when the recurrent infection presents intraorally in an immunocompetent patient, the vesicles and ulcers appear on the keratinized mucosa (palate and attached alveolar gingiva). The most common triggers include sun exposure, trauma, and physical or emotional stress. The patient did report a stressful finals week concluding just four days before the onset of the acute painful lesion. The evidence against this being recurrent herpes infection is the appearance of a solitary erythematous nodule in the midline. There is a lack of viral appearance to the patient’s lesion presented. There are no crops of vesicles or coalescing ulcers. Additionally, recurrent herpes infection follows the neural pathway and, therefore would favor a location lateral to the midline of the palate. Salivary gland tumors are uncommon and mostly occur in the parotid gland. The most common intraoral location for a parotid tumor is the palate. The palate harbors hundreds of minor salivary glands, and 42-51% of intraoral (excluding the major glands) minor salivary gland tumors occur in the palate (1,3). The most common benign salivary gland tumor is the pleomorphic adenoma, and the most common malignant salivary gland tumor is the mucoepidermoid carcinoma. Clinically, a salivary gland tumor will likely present as a painless, slow-growing mass. When the swelling is on the palate, the location of the tumor tends to favor the posterior lateral aspect (1). The typical clinical findings of a salivary gland tumor are inconsistent with our symptomatic, erythematous, acute swelling on the palate. The median palatal cyst is a developmental fissural cyst that occurs along the plane of fusion between the lateral palatal shelves of the maxilla. As the shelves fuse in an anterior-posterior direction, epithelium may get entrapped and form a cyst. The cyst often presents in adults aged 20-50 years old with an average age of 37. A median palatal cyst occurs as a midline swelling posterior to the palatine papilla (2). Most frequently, the lesion is asymptomatic, but occasionally, mild symptoms of pain or expansion are reported (1). The average size of the cyst is 2 x 2 cm, and it appears ovoid or concentric on an occlusal radiograph (1). The quick onset, pain, and erythema of the palatal lesion presented is not suggestive of a median palatal cyst. Squamous cell carcinoma (SCC) is the most common malignancy of the oral cavity representing over 90% of intraoral cancers. The most common location for the development of intraoral SCC is the posterior lateral and ventral tongue, followed by th floor of mouth. The palate would represent one of the least common sites for intraoral cancer (1). Clinically, SCC can present as an exophytic or endophytic lesion. SCC can also be a leukoplakia, erythroplakia, or erythroleukoplakia. SCC usually begins as an asymptomatic lesion that becomes symptomatic over time if untreated. Necrotizing sialometaplasia (NS) is an uncommon condition that is thought to arise from ischemia to the salivary glands. Potential risk factors leading to ischemia include traumatic injuries, dental infections, ill-fitting dentures, upper respiratory infections, adjacent tumors,

previous surgery, and eating disorders (1). The ischemia leads to tissue necrosis of the regional mucous gland lobules and a destructive inflammatory response to local tissue. More than 75% of NS cases occur on the palate, making it by far the most common location, but they can also be found in other oral locations with minor salivary glands or major salivary glands (1). The lesion begins as a nonulcerated, swelling often with pain or paresthesia, and then after 1-3 weeks the necrotic tissue can slough or “fall out”, and complete healing occurs over the 4-10 weeks. The lesions can range in size from 1 – 5 cm. Larger lesions require a longer healing duration (4). About two-thirds of palatal lesions are unilateral; however, bilateral synchronous and metachronous lesions can occur, as can midline lesions (4).

There was a high index of suspicion for necrotizing sialometaplasia from the clinical presentation and progression. Therefore, the treatment recommended was over-the-counter analgesics and close monitoring of the area over the next several days. The patient was given a thorough explanation thathe area may worsen in appearance by becoming a larger ulcer and tissue necrosis may result in exfoliation of tissue before eventually healing. If concern over the appropriate working diagnosis arises, then biopsy would be warranted. On day 5, after initially becoming aware of the lesion while brushing her teeth, the area was less painful and showed a small central ulcer covered with fibrin surrounded by an erythematous swelling. The lesion had become asymptomatic and almost completely healed over the ensuing 5 days (see photos 3 and 4). This case represents idiopathic necrotizing sialometaplasia (NS) because no traumatic etiologic factor could be identified. This case is also a quickly resolving example because many lesions take 4-10 weeks to heal (4). The clinical presentation can be quite concerning for a malignancy, and often these lesions are biopsied. Histopathologically, NS mimics squamous cell carcinoma because of the squamous metaplasia of salivary ducts and regional mucous gland acinar necrosis. Furthermore, an area of pseudoepitheliomatous hyperplasia of overlying epithelium may occur over the area, mimicking the appearance of squamous cell carcinoma. The young age of the patient, location, acute symptoms, and lack of any other contributing medical or social history elevated the likelihood of NS to the top of the differential. Therefore, a wait-andwatch approach over several days was appropriate for patient management. The diagnosis was confirmed by the clinical course, and biopsy was able to be avoided.

REFERENCES 1)NEVILLE B.W., DAMM D.D., ALLEN C.M., CHI A.C. SALIVARY GLAND PATHOLOGY. IN: NEVILLE B.W., DAMM D.D., ALLEN C.M., CHI A.C., EDITORS. ORAL AND MAXILLOFACIAL PATHOLOGY. 4TH ED. ELSEVIER; ST LOUIS: 2016. PP. 28;123-124;439–445.

2) MANZON, S., GRAFFEO, M., & PHILBERT, R. (2009). MEDIAN PALATAL CYST: CASE REPORT AND REVIEW OF LITERATURE. JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY, 67(4), 926–930.

3) JONES, A. V., CRAIG, G. T., SPEIGHT, P. M., & FRANKLIN, C. D. (2008). THE RANGE AND DEMOGRAPHICS OF SALIVARY GLAND TUMOURS DIAGNOSED IN A UK POPULATION. ORAL ONCOLOGY, 44(4), 407–417. 5) BEN-IZHAK, O., & BEN-ARIEH, Y. (1993). NECROTIZING SQUAMOUS METAPLASIA IN HERPETIC TRACHEITIS FOLLOWING PROLONGED INTUBATION: A LESION SIMILAR TO NECROTIZING SIALOMETAPLASIA. HISTOPATHOLOGY, 22(3), 265–270. DOI:10.1111/J.1365-2559.1993. TB00117.X

ABOUT THE AUTHOR

Dr. Faram is an Oklahoma native and a member of the Choctaw Nation of Oklahoma. He completed his undergraduate studies at Oklahoma City University and is a graduate of OU College of Dentistry. Dr. Faram has a special interest in public health and community dentistry and worked for the Cherokee Nation as a general dentist for five years in Tahlequah, OK. He completed a residency in Oral and Maxillofacial Pathology at New York Presbyterian, Queens, and is thankful to return home to provide care for patients at OU Health. In his free time he enjoys visiting local lakes, vacationing with his family, and cheering on the Sooners.