The objective of this study was to compare mast cell density (MCD) in oral epithelial dysplasias (OED) and oral squamous cell carcinoma (OSCC) and determine its correlation with clinical and histopathologic parameters and the degree of tumor differentiation. Thirty OSCC samples, 14 OED samples, and 4 non-neoplastic oral mucosa samples were analyzed by immunohistochemistry to determine MCD based on the expression of MC tryptase. In addition, MCs were categorized morphologically into degranulated and granulated cells. MCD was significantly higher in OSCC lesions with a greater degree of differentiation (P=0.04). No significant difference in MCD was detected between mild and moderate OED samples (P=0.09). Our findings indicate that MCs are present in the tumor microenvironment and may be associated with a better prognosis.

To the Editor: The calcifying epithelial odontogenic tumor (CEOT) is an uncommon benign tumor of epithelial origin, representing <1% of all odontogenic tumors. Among the histological variants of CEOT, the true cystic variant of CEOT is extremely rare, with only 3 welldocumented cases reported in the English-language literature. [1][2][3] In this report, we describe the clinical, radiographic, and histopathological features of a case of cystic variant of CEOT.A 22-year-old male patient was referred to evaluation of a gingival swelling with approximately 8 months of evolution. Intraoral examination revealed a painless, dome-shaped, nodular lesion, which presented a bluish color and soft/cystic consistency to palpation. The nodule was located on the attached gingival mucosa and mobile alveolar mucosa, between the right mandibular canine and right mandibular first premolar (Fig. 1A). Radiographically, a well-circumscribed, ovoid, unilocular, mixed radiopaque, and radiolucent lesion was observed, measuring 2.0 cm of extension. The lesion was located between the right mandibular canine and first premolar and caused divergence of the roots of the involved teeth. Moreover, discrete root resorption on the first premolar was also observed (Fig. 1B). Occlusal radiography showed expansion and rupture of the buccal cortical bone, with the presence of numerous small, round, and radiopaque formations. An exploratory needle aspiration was performed, which showed an abundant amount of liquid. After aspiration, a significant decrease in swelling was observed. According to the clinical and radiographic findings, a calcifying cystic odontogenic tumor was the main hypothesis of diagnosis.Under local anesthesia, the lesion was excised, with subsequent curettage of the surrounding bone tissue (Fig. 1C). Microscopically, most of the lesion appeared as cystic cavities lined by polyhedral epithelial cells associated with numerous calcifications (Fig. 1D). In the cystic lining, these polyhedral epithelial cells were interspersed by calcifications (Fig. 1E). Extensive concentric calcifications were frequent in the stroma and between the tumor cells. Clear cells were commonly observed. In addition, focal areas with amorphous, eosinophilic, and hyalinized material positive for Congo red staining were also noticed (Fig. 1F). Thus, the diagnosis of calcifying epithelial odontogenic tumor, cystic variant, was established. One year after the excision, there was complete bone healing. Currently, 10 years after treatment, no clinical and radiographic signs of recurrence were observed.The most common clinical feature of CEOT is a firm, painless expansive mass located in the posterior region of the mandible. 4 In contrast, the current case showed an unusual presentation, appearing as a well-circumscribed gingival nodule with a blue-colored surface and soft consistency. These atypical features may be related to cystic presentation of the CEOT, which showed an expansive growth rather than infiltrative. In the same way, radiographically, this case show...

In oral squamous cell carcinoma (OSCC), involvement and activation of the Hedgehog pathway (HH) may be related to epithelial-mesenchymal transition and cell proliferation. The present study aimed to evaluate epithelial-mesenchymal transition and proliferative potential in OSCC cases demonstrating activation of the HH pathway. Twenty-three GLi-1-positive OSCC cases were submitted to immunohistochemical detection of Snail, Slug, N-cadherin, E-cadherin, β-catenin, and MCM3 proteins. Clinicalpathologic immunoexpression data were obtained from the invasion front and tumor islets, and then compared. At the invasion front, OSCC cases presented positive Snail, Slug, and MCM3 expression in the nuclei of tumor cells. Loss of membrane and cytoplasmic expression of E-cadherin and β-catenin was also observed. Positive N-cadherin expression was observed in 31.78% of the cases. GLi-1 immunoexpression was associated with loss of membrane E-cadherin (P < 0.001), membrane β-catenin (P < 0.001), and cytoplasmic β-catenin (P = 0.02) expression. In the tumor islets, we observed nuclear expression of GLi-1, Snail, Slug, and MCM3. E-cadherin and β-catenin showed positivity in tumor cell membranes. Statistically significant positive correlations between GLi-1 and Snail (P = 0.05), E-cadherin (P = 0.01), and cytoplasmic β-catenin (P = 0.04) were found. GLi-1 was associated with clinical staging, while membrane β-catenin expression was related to the presence of metastasis in lymph nodes and to clinical staging. The HH pathway may be involved in regulating the expression of the mesenchymal phenotype. The loss of membrane E-cadherin and β-catenin expression was observed at the tumor front region, whereas cell adhesion protein expression was detected in tumor islets regardless of MCM3.