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BACKGROUND & OBJECTIVES: Odontogenic cysts are among the most frequent destructive lesions of jaws which their pathogenesis and growth mechanism are not cleared. With respect to different roles of mast cells, they may play a role in the pathogenesis and growth of odontogenic cysts. The aim of present study was to evaluate mast cells in the most common odontogenic cyst. METHODS: Thirty paraffin-embedded tissue blocks including 10 radicular cysts, 10 dentigerous cysts and 10 odontogenic keratocysts were used and 5 micron sections stained with toluidine blue and observed by light microscope under ×400 magnification to evaluate mast cells within these cysts. For each case, 5 high-power field areas, selected from hot-spot areas, were considered and each area divided into 3 zones: intra-epithelial zone, sub-epithelial zone and deep zone. RESULTS: Most of the studied cyst showed presence of mast cells. There was not any significant difference in mast cell count between studied cysts ( P -values > 0.05).With respect to intra-epithelial, sub-epithelial and deep zones, there was not any significant difference between three studied cysts. There was not any significant difference between sub-epithelial zone and deep zone within each of these cysts. There was only significant difference between intra-epithelial zone and sub-epithelial zone within dentigerous cysts and odontogenic keratocysts ( P -value < 0.05). CONCLUSIONS: Prevalence of mast cells in fibrous wall of odontogenic cysts suggests their activity in these cysts. Mast cells may not be directly involved in the pathogenesis of odontogenic keratocysts.
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BACKGROUND: Adenoid cystic carcinoma (AdCC) is a malignant salivary gland neoplasm with poor long-term prognosis. Differentiating between AdCC and other salivary gland neoplasms can be a diagnostic challenge, particularly in examining tissues obtained from small incisional biopsies. AIM: The aim of this study was to evaluate c-kit expression in four common benign and malignant salivary gland neoplasms. MATERIALS AND METHODS: Immunohistochemical techniques were used to analyze the level of c-kit expression in normal salivary gland (n = 10) and four different types of salivary gland tumors: Pleomorphic adenoma (PA) (n = 17), AdCC (n = 9), polymorphous low-grade adenocarcinoma (PLGA) (n = 4) and mucoepidermoid carcinoma (MEC) (n = 6). Samples were immunostained using monoclonal antibody against c-kit. RESULTS: The immunoreactivity for c-kit was found in all cases of AdCC, PLGA and MEC and majority of PAs. Positive reactivity was observed in more than 50% of the tumor cells of AdCC and less than 50% in PLGA. PA did not show strong immunostaining and c-kit was predominantly localized to the cell membrane. Furthermore, the difference in the expression of c-kit between the benign and malignant neoplasms was not statistically significant. CONCLUSIONS: CD117 expression itself cannot be used as a marker in differential diagnosis of salivary gland neoplasms. However, the percentage of the CD117 immunoreactive cells and the staining intensities appeared to be important factors in distinguishing AdCC from PLGA and PA.
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INTRODUCTION: Metastatic lesions of the oral cavity are extremely rare, accounting for approximately 1% of all malignant oral tumors. The most common primary sources of metastatic tumors in the oral region are, from the most to the least common, the breast, lung, kidney, bone, and colon. Renal cell carcinoma accounts for nearly 3% of all adult malignancies. It usually metastasizes to the lungs, bone, adrenal glands, and regional lymph nodes. The incidence of metastasis from renal cell carcinoma to the head and neck region is very low. The tongue is considered a very rare atypical ear, nose, and throat (ENT) location for metastasis of renal cell carcinoma. The present case from Iran reports tongue metastasis of renal cell carcinoma (RCC). CASE REPORT: The following report is based on an 80-year old male patient with a tongue lesion and ambiguous past medical history that ultimately leads to diagnosis of a metastatic RCC. We also updated a previous literature review that was published 2008. A histopathological differential diagnosis for clear-cell tumors is also discussed. CONCLUSION: Because of the rarity of metastatic tumors of the oral region as well as the presence of other lesions with clear cells, diagnosis of metastatic clear-cell RCC in the oral cavity can be very difficult and challenging.
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OBJECTIVE: Ameloblastoma and keratocystic odontogenic tumor (KOT) is characterized by a benign but locally invasive behavior with a high risk of recurrence. MDM2 (murine double minute 2), an amplifier of cell proliferation, and p53, a tumor suppressor gene, are overexpressed in some odontogenic lesions. The aim of this study was to compare the expression of MDM2 and p53 in ameloblastoma and KOT as 2 lesions with similar biologic behavior, by immunohistochemistry. METHODS: The expressions of MDM2 and p53 proteins were determined in 39 ameloblastomas (15 follicular types, 15 plexiform types, and 9 unicystic types) and 15 KOTs. RESULTS: P53 protein was expressed in 100% of KOTs and 77.8% of ameloblastomas, and MDM2 was detected in 74.8% of ameloblastomas and 80% of KOTs. There was no statistical difference between MDM2 and p53 expressions in different subtypes of ameloblastomas and also when KOTs were compared with them (P > 0.05). There was a significant difference between immunohistochemical reactivity of MDM2 among subtypes of ameloblastomas (P < 0.05). MDM2 and p53 expressions were positively correlated. CONCLUSIONS: Overexpression of p53 and MDM2 is associated with the pathogenesis and oncogenesis of ameloblastomas and KOT. Overexpression of these markers can contribute to similar biologic behavior of these lesions.