History of Present Illness
The patient had noticed a swelling in his palate for approximately two weeks. He had not experienced any previous swellings in his palate and did not recall any trauma prior to the onset of the swelling. He had not received any recent dental treatment. The swelling was completely asymptomatic and the patient had no other complaints.
Past Medical History
The patient reported a history of epilepsy, but he apparently was not receiving any anti-seizure medication at the time of examination. The remainder of his medical history was unremarkable and review of systems did not reveal any other abnormalities.
Clinical and Radiographic Findings
Clinical examination revealed a 2.5 x 3.0 cm raised firm nonindurated mass on the left hard palate. The epicenter of the mass was adjacent to the maxillary left first molar and the lesion extended to the midline (Figure 1). The lesion was compressible to palpation and demonstrated a slight bluish hue. The remainder of the oral cavity was within normal limits. The patient’s dentition was in good repair and several cast gold restorations were present. Radiographs of the left maxilla were negative for any pathology and all teeth in the area tested vital.
Figure 1. Smooth-surfaced raised lesion of left hard palate.
Incisional Biopsy and Photomicrographs
An incisional biopsy was performed by obtaining a full-thickness wedge of mucosa taken from within the confines of the mass down to the periosteum. Microscopic examination revealed a wedge of mucosa surfaced by keratinized stratified squamous epithelium overlying minor salivary gland tissue. An area of necrosis was also identified (Figure 2).
Figure 2. Low power photomicrograph showing non-ulcerated mucosa overlying fibrous connective tissue and minor salivary glands. Necrosis can be seen in the lower right aspect.
In areas, numerous islands of squamous epithelium were identified adjacent to minor salivary gland acini and ducts (Figure 3).
Figure 3. Low power photomicrograph showing numerous islands of squamous epithelium adjacent to minor salivary gland tissue.
Closer inspection revealed lobular (coagulation) necrosis of numerous salivary gland acini (Figure 4) and squamous metaplasia involving salivary gland ducts (Figures 5 and 6). In addition, granulation tissue admixed with neutrophils, lymphocytes, and foamy histiocytes was identified.
Figure 4. Medium power photomicrograph showing lobular necrosis of minor salivary gland acini.
Figure 5. Medium power photomicrograph showing squamous metaplasia of minor salivary gland ducts.
Figure 6. High power photomicrograph of squamous metaplasia. A residual lumen is still evident in one of the ducts.