Human DEK gene on chromosome 6p encodes a 43kD nuclear phospoprotein that was originally identified as part of a fusion protein found in a subset of acute myeloid leukemia carrying a t(6;9) translocation. Although DEK upregulation has been described in a number of human malignancies and was significantly associated with high histologic grade, lymph node metastasis and/or advanced clinical stage, no previous report has evaluated the expression of DEK protein and its clinical significance in oral squamous cell carcinoma (OSCC). Our aims were to determine DEK expression in tissue samples of normal oral mucosa and OSCC by immunohistochemistry, to analyze the correlation between DEK expression and clinicopathological parameters, and to evaluate the value of DEK as a prognostic marker for patient’s survival. Ten normal oral mucosa, 10 epithelial dysplasia, and 60 OSCC samples were studied by immunohistochemistry. DEK expression tended to increase through the full thickness of epithelium in the dysplastic mucosa when compared with those in normal oral mucosa. High expression of DEK protein (score ≥ 2) was found in 68.3% of OSCC cases. Statistical analysis revealed that DEK overexpression in OSCC was positively correlated with high histologic grade (p=0.001), lymph node metastasis (p=0.003), and advanced clinical stage (p=0.039). In the Kaplan-Meier survival analysis, DEK overexpression was significantly associated with decreased overall survival in patients with OSCC (p=0.019). Our results suggest that DEK overexpression may be a reliable marker to predict the clinical outcome in OSCC.

Fibromatoses are benign fibroblastic proliferation, which forms infiltrating tumor-like mass. Their histologic features cannot reflect the biologic behavior; local recurrence and aggressive infiltration to the adjacent tissue make fibromatoses intermediate tumor, between benign and malignant. Infantile fibromatosis consists of desmoid-type tumor and lipofibromatosis, and mainly affects children under age of 10. While desmoid-type tumor is characterized by elongated mature fibroblastic proliferation, the fibroblasts in lipofibromatosis look more primitive and accompany adipocytes. Here, we report a case of infantile fibromatosis of 4 month old boy involving the tongue.

Many researchers have been reported recent trends for rising incidence particularly related to cancer of the tongue in young people. The purpose of this study is to exam the changes of OSCC(oral squamous cell carcinoma) incidence distribution. After Institutional Review Board approval, 1,345cases of OSCC were reviewed from 1993 to 2012 at the department of Oral Pathology at the University of Seoul National Dental Hospital with respect to gender, age, locations. As the results, the most prevalence ages were between 45-69 years old(mean:59.68). There is a noticeable incidence on the eighth decade of life. There are no changes of incidence distribution on se (male:female=69:31) at each year. The most common incidence area was tongue at 1993 but the mandible was the most popular site after 2001. Comparing the incidence rates of the predilection sites over and under 44 years old patients, among patients under 44 years old showed the tongue is the common site steadily. On the other hand, there is a significant increase on the mandible in the over 44 years old patients. In conclusion, this study showed similar results on overall sex distribution and median ages. The trends of locations over 20 years have been increased on the old adult’s mandible. Also, tongue is the common site for the young adults constantly. There are needs for further studies to elucidate the behind etiology. In addition, the true impact of young age on OSCC clinical behavior will remain difficult to determine unless intranational and multi-institutional databases will be combined.

Lysyl oxidase (LOX) family, the copper dependent amine oxidase, oxidizes lysine residues in extracellular collagen and elastin. LOX increases the strength of the extracellular matrix and plays an important role in tumor development and metastasis. It has been reported that increased LOX protein and RNA are found in head and neck squamous cell carcinoma. Moreover some studies regarded LOX as a prognostic marker of oral and oropharyngeal squamous cell carcinoma. However there has not been any report on LOX expression of salivary gland tumors. Here, we investigated LOX expression in mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC) of salivary gland and compare it to those of pleomorphic adenoma (PA). We evaluated LOX expression in eighteen MEC, eighteen ACC and twenty PA cases by immunohistochemical examination. Whereas PA showed relatively low density of LOX expression, ACC revealed more cases that showing high staining intensities for LOX. Significantly increased LOX expression was found in the cases of ACC when compared to those of PA (P = 0.010).

A poor prognosis of oral squamous cell carcinoma (SCC) is partly due to the invasiveness and metastasis of the tumor. One of key elements in tumor invasion and metastasis in the degradation of extracellular matrix is tissue inhibitors of metalloproteinases (TIMPs). This study was performed to determine the expression of TIMP-1 and TIMP-2 of oral SCCs with regard to the histologic invasiveness and differentiation in 5 normal oral mucosa and 36 oral SCCs. The histologic invasiveness of oral SCCs were classified into 4 grades. The differentiation of oral SCCs was divided into 3 grades. The StreptAvidin-Biotin immunohistochemical process, using TIMP-1 and TIMP-2 monoclonal antibodies, was performed to determine the expression of TIMP-1 and TIMP-2. The expression of TIMP-1 was positive in 5 of 17 oral SCCs with weak invasiveness and was positive in 8 of 19 oral SCCs with strong invasiveness. The TIMP-1 expression did not increase significantly with respect to the invasiveness of oral SCCs (P>0.05). The expression of TIMP-2 was strongly positive in 5 out of 17 SCCs with weak invasiveness and was strongly positive in 15 of 19 SCCs with strong invasiveness. The TIMP-2 expression increased significantly with respect to the invasiveness of oral SCCs; the stronger the expression, the stronger the invasiveness (P<0.05). The expression of TIMP-1 and TIMP-2 did not increase significantly with respect to the histologic differentiation. We concluded that with respect to the invasiveness, the TIMP-2 expression increases significantly in oral SCCs but the TIMP-1 expression does not; and that with respect to the histologic differentiation, their expressions do not increase significantly. These results suggested that TIMP-2 can be used as a tool to evaluate the invasiveness of oral SCCs.

Clear cell odontogenic carcinoma (CCOC) is a very rare malignant neoplasm of jaw, with a significant clear cell component. It is nearly three times as common in the mandible with distinct female predominance. Past, identified as locally invasive tumor, CCOC is now considered to be malignant neoplasm, showing distant and regional lymph node metastasis. CCOC is histopathologically characterized by large glycogen-rich clear cells, often intermixed with eosinophilic cells. When diagnosing CCOC, ruling out salivary gland tumors, such as mucoepidermoid carcinoma or clear cell adenocarcinoma is important because they have overlapping histologic features with CCOC. Here in, we report a case of CCOC involving the right maxillary sinus of a 72-year-old female.

A mucocele is a pseudocyst containing spilt mucin from extravasation of the oral minor salivary gland. For this study, 115 cases of mucoceles diagnosed at the Department of Oral Pathology, Seoul National University Dental Hospital were reviewed with respect to gender, age, lesion’s site, size, color, histopathologic features, and recurrence. There was no significant difference between male and female. Nearly 80% cases occurred in young people under the age of 30 (29.7% in the third decade with the highest prevalence). The lower lip (75.7%) was the most common site, followed by ventral surface of the tongue, mouth floor, and buccal mucosa. The lesions measured from 2 to 20 mm in diameter and appeared in various colors. Histopathologically, mucoceles showed pseudocystic cavities containing mucin surrounded by granulation tissues with foam cells. Among the 115cases, 14 showed recurrence on the adjacent sites. Those cases treated with and without removal of the feeding glands on excision of mucoceles showed recurrence rates of 9.2% and 18.0%, respectively. Based on these results, it is recommended that mucoceles be treated with surgical excision of the feeding salivary glands. There were no clinicopathological results significantly different from the established facts regarding the mucoceles of Korean patients

Clear cell adenocarcinoma (CCA) is a rare malignant neoplasm of salivary gland that represents only 1% of all salivary gland tumors. CCA is histopathologically characterized by monotonous, glycogen-rich, round to ovoid clear cells intermixed with hyalinized stroma. However, other salivary gland tumors such as mucoepidermoid carcinoma, acinic cell adenocarcinoma, oncocytoma, epithelial-myoepithelial carcinoma, and myoepithelial carcinoma should be ruled out to diagnosis CCA. We herein report a case of CCA involving the soft palate in a 56-year-old female. It is essential to consider CCA in the differential diagnoses of clear cell tumors.

Neurotized melanocytic nevus (NMN) is categorized into intradermal/intramucosal type of acquired melanocytic nevus. In contrast to typical intramucosal nevus which has relatively distinct histological features, the diagnosis of NMN requires more attention due to its mimicry of benign neural tumors such as neurofibroma. The majority of lesional cells, NMN cells, showed a spindle cell morphology and abundant, eosinophilic cytoplasm which were positive for S-100, vimentin, and collagen type IV. Positive reaction for MART-1 was detected in the NMN cells as well as in the epithelioid nevus cells beneath the epithelium. Neurofibroma exhibited diffuse positivity for S-100, vimentin, CD34 and collagen type IV, but never expressed MART-1. Toluidine blue stained the numerous mast cells scattered in the lesion of neurofibroma, compared to the relatively minor detection of mast cells in NMN. Therefore, MART-1 is a useful marker in differentiating NMN from neurofibroma.

Oral squamous cell carcinoma (OSCC) is one of the most common carcinomas in the head and neck area. Bitter melon extraction (Momordicacharantia, BME) has been used as a functional food to prevent and treat human health related issues. It has recently been reported that BME inhibits breast cancer cell growth by arresting cell cycle and promoting apoptosis. In this study, we aimed at proving the inhibitory action of BME on OSCC proliferation. We used two OSCC cell lines, SCC4 and Ca9-22. Both cell lines were treated with different concentrations (1%, 2%, and 5%) of BME. Cell viability was examined by MTT assay. DNA condensation was visualized by immunofluorescence microscope to determine the signs of the cell apoptosis. Cell numbers were significantly decreased in a dose-dependent manner by bitter melon at concentration of 1% of BME on Ca9-22 cell line (P=0.001) but no significant effect on SCC4 (P=0.124) at the same concentration. 2% BME treatment of the Ca9-22 cell line induces chromatin condensation and DNA fragmentation after 20 hours. It seems that BME inhibits the proliferation of Ca9-22 cell line by inducing apoptosis. Thus, BME may be used as a dietary supplement for prevention of OSCC.

Oral squamous papilloma (OSP) is a common benign lesion of the oral mucosa that is induced by the human papillomavirus. To investigate the clinicopathological characteristics of OSP, we selected 135 patients diagnosed at the Seoul National University Dental Hospital. OSPs occurring in Koreans had a slight female predilection, with the male to female ratio being 1:1.6. The age ranged from 4 to 80 years old (average age: 47 years). The most frequent location was the soft palate (43.7%), followed by the tongue and gingiva. 11.1% of all patients presented with pain. There have been no reported cases of recurrence. On microscopic examination, two‐thirds of the lesions were parakeratinized, with almost all cases (99%) containing the koilocytes. In conclusion, there were no significant differences between the clinicopathological features of OSP in Korean and findings from previous studies

Numerous reports on the immunopathogenesis of an oral lichen planus (OLP) have shown some inconsistency in terms of the role and distribution of CD4+ and CD8+ T cells, and Langerhans cells (LC). This has led to the hypothesis that although the clinical and histopathological manifestations of OLPs appear similar, they can be grouped into CD4+ predominant lesions and CD8+ ones on the varied immunopathogenesis or clinical progress. This study investigated the distribution of CD4+ T cells, CD8+ T cells, LC and the ratio of CD4/CD8 and defined the important immunocompetent cells. In addition, the clinicopathological and histopathological correlation with those immunocompetent cells were investigated. Frozen sections of 16 OLPs and 5 normal buccal mucosae were immunostained. Quantification was done using KAPPA Imagebase software and statistical analysis using SPSS 10.0 statistical package. CD8+ T cells were consistently more abundant in the epithelium of the OLP than CD4+ T cells, but no difference between the two cells was detected in the lamina propria. The intra-epithelial CD4+ T cells revealed a positive linear correlation with the intra-epithelial CD8+ T cells. In the lamina propria, the number of LC had a positive linear correlation with CD4/CD8 ratio. The number of LCs was higher in the reticular type of OLP compared to the erosive type. The histopathological features such as hyperkeratosis, acanthosis, the band-like infiltration of mononuclear cells, and liquefaction degeneration did not show significant correlation with the CD4/CD8 ratio. The results suggest that CD8+ T cells play major role in immunopathogenesis of OLP. The immunopathogenesis of OLP appears to vary from lesion to lesion in relation to the clinical progress.

Chronic hyperplastic candidiasis (CHC) is characterized by epithelial hyperplasia of the oral mucosa associated with candidal hyphae. The immune status of host is one of the factors that induce clinically evident candidal infection. Host defense mechanisms include inflammatory cells, epithelial barrier, and antimicrobial peptides such as human beta 2 defensin (hBD-2). In the present study, we investigated the densities of CD4+/CD8+ T lymphocytes and hBD-2 expression of epithelial cells in CHC. Immunohistochemical staining was performed on 10 cases of CHC using CD4, CD8 and hBD-2. Ten specimens of chronic mucositis were selected for comparison, and went through the same examination. hBD-2 was expressed in the spinous cell layers and the keratin layers of 7 CHC patients, while the epithelium of chronic mucositis did not demonstrate the hBD-2 expression except for one case. Also, hBD-2 expression was stronger when the hyphae invaded the upper stratum spinosum (P =.019). However, the densities of CD8+ T lymphocytes were significantly lower in the CHC patients, suggesting that the ability of CD8+ T cells to enter the epithelium and target the pathogenic hyphae was decreased in CHC. Increased hBD-2 expression seemed to be significantly associated with the candidal infection, while not promoting the cell-mediated immune reaction in CHC.

Sialolithiasis consists of calcified structures in either the salivary gland or ductal system and alteration of salivary gland parenchyma. To investigate the clinicopathological features of sialolithiasis in Korean patients, we selected 60 patients with sialolithiasis diagnosed at the Seoul National University Dental Hospital. Their clinical records and radiographs were reviewed with the analysis of available histologic data from 32 cases. The male to female ratio was 1.1:1. Sialolithiasis is most common between the ages of 20 and 60 years and occurred most frequently in the submandibular gland (97%). Upon microscopic examination, most lesions showed moderate-to-severe inflammatory infiltration and parenchymal changes such as ductal metaplasia, acinar necrosis and fibrosis. Consequently, Korean patients exhibited clinicopathological features similar to those previously reported.

Both synovial cysts and synovial chondromatoses originate from synovial tissue, and only one case has been reported to occur simultaneously in a patient. Our patient presented with a swelling of the right preauricular area and pain on opening the mouth. Magnetic resonance images demonstrated two cystic structures in the superficial lobe of right parotid gland. Under the clinical impression of a cyst in the salivary gland, an enucleation was performed. However, the final diagnosis based on microscopic examination was a synovial cyst associated with the right temporomandibular joint and a synovial chondromatosis arising within the cystic wall. Awareness of this combined lesion will help make a diagnosis and establish a proper treatment plan.

Pleomorphic adenoma (PA) is the most common benign salivary gland tumor. It is biphasic and is characterized by an admixture of epithelial and spindle-shaped myoepithelial cells in a variable background stroma. Epithelial-myoepithelial carcinoma (EMC) is a malignant biphasic salivary gland tumor typically composed of clear myoepithelial cells that surround epithelial-lined ducts resembling intercalated ducts. The differential diagnosis between the two tumor may be occasionally encountered because of the shared histophatologic feature. And then, it would be more reliable to differentiate the tumors based on biological behavior such as the expression of distinct intermediate filaments such as cytokeratin, invasiveness- related molecules, and the growth factor receptor to aberrantly facilitate the tumor growth, and the growth fraction of tumors. Therefore, from the 10 cases of PA and 6 cases of EMC, we immunohistochemically examined the differential expression of the cytokine 7 and 14, matrix metalloproteinase-9, C-KIT, and Ki-67 between the two tumor. At the results, there were significant differences of CK7 expression in non-luminal cells (P = 0.000) and CK14 expression in luminal and non-luminal cells of the both tumors (P = 0.025 and P = 0.000, respectively). In the comparison of the biologic behavior, a significantly increased expression of MMP-9, C-KIT and Ki-67 was found in the cases of EMC when compared to those of PA (P = 0.043, P = 0.011, and P = 0.000, respectively). In conclusion, the differences of CK expression in luminal and non-luminal cells between PA and EMC seem to reflect the difference of the origin and the level of the maturation of the tumor cell. Increased expression of MMP-9, C-KIT, and Ki-67 in EMC may represent more aggressive biologic behavior of the tumor compared with benign salivary tumor such as PA. Our results may be helpful to understand the histiogenesis of the two tumors and the difference of biologic behavior and to differentiate them when the limited specimen was submitted. Further study of many more cases of EMC is needed to validate the usefulness of these molecules as the diagnostic aid.

Central granular cell odontogenic tumor (CGCOT) is a rare benign odontogenic neoplasm, with approximately 30 cases having been reported. The pathogenesis of CGCOT as well as the designation of this lesion is controversial because of unknown histogenesis of the granular cell. We present an additional case of CGCOT involving the mandible of a 50-year-old Korean man who complained of asymptomatic swelling of the right buccal gingiva. Current lesion is microscopically characterized by densely packed polyhedral granular cells surrounding interspersed islands or strands of odontogenic epithelium. Immunohistochemically, granular cells were positive for Vimentin and CD68, and negative for cytokeratin and S-100. These features support a mesenchymal origin for the granular cells as other results previously reported.

Langerhans cell histiocytosis (LCH) is a rare clinicopathologic disorder characterized by proliferation of histiocyte- like cells (langerhans cell histiocytes) accompanied by varying other inflammatory cells. LCH commonly involves the oral and maxillofacial region, but is very rarely seen. Then LCH has made it difficult to investigate the clinical and histological aspects. We investigated LCH of oral and maxillofacial region and analyzed clinical and histological characteristics. We reviewed the records of all patients who were diagnosed as LCH, retrospectively. Data included patient’s age, sex, chief complaint, clinical diagnoses, radiologic and histologic reports, and clinical course. We analyzed clinical and histological characteristics. From 2000 to 2007, 8 patients were diagnosed as LCH. 7 were children and 1 was adult. All cases involved mandible. Clinical type of all cases were“eosinophilic granuloma”. 6 cases were classified as“unifocal disease”and 2 cases were“multifocal single system diseases”. Microscopic findings commonly showed numerous histiocytes with eosinophilic cytoplasm (langerhans histiocytes). In 6 cases, immunohistochemical study was accomplished and confirmed the diagnosis of LCH. 6 cases were cured and not recurred, and 2 cases had loss of follow- up. Unifocal disease type of LCH may arise in Korean people more frequently than in western people (75% Vs 49%). Therefore, the higher frequency of unifocal disease of LCH is expected to raise the cure rate and to improve patient prognosis in Korean patients with LCH.

Desmoplastic ameloblastoma (DA) and Ameloblastic fibroma (AF) show common histopathologic features such as enamel organ like epithelial islands or cords on the background of abundant fibrous stroma. Despite their similar histopathologic features, it was reported that they have different pathogenesis and clinical behavior. The purpose of this study was to rev iew clinicopathologic features of DA and AF among Korean subjects. 7 cases of DA and 4 cases of AF were retrieved from the files of Seoul National University Dental Hospital (SNUDH), and their clinical features, radiographic findings, and histopathologic features were reviewed and compared. DA occurred in 3 males and 4 females. They occurred from 24 to 62 years of age, showing the mean age of 42.7 years. 5 of the 7 tumors occurred in the maxilla, and all of them in the anterior region, showing predilection for the maxillary anterior regions. There was no recurrence. Radiographically, they showed well demarcated unilocular or multilocular radiolucency. AF occurred in 5 males and 2 female. They occurred from 6 to 29 years of age, showing the mean age of 14 years. All tumors occurred in the mandibular molar area. Recurrence was recognized in 1 case. Although DA and AF showed similar histopathologic features, they showed different clinical behaviors. While DA showed predilection for the anterior maxilla, AF did for posterior mandible. While DA occurred mainly in adults, AF did in adolescents. Recurrence was recognized not in DA but in AF. Therefore, DA and AF should be differentiated from each other in spite of similar histopathologic findings

Glandular odontogenic cyst (GOC) is a rare odontogenic cyst, which shows cystic structures lined by stratified squamous epithelium with various thickness. Glandular duct-like spaces lined by eosinophilic cuboidal or columnar cells constitute the epithelial surface. The purpose of this study was to present 7 cases of GOC retrieved from the files of the Department of Oral Pathology, Seoul National University Dental Hospital and to investigate the immunohistochemical expression of cytokeratins (CKs) in the epithelial components. A total of 7 GOCs were reviewed clinically and radiographically and immunostainning for CK 5, 7, 14, 18 and CK-pan were performed. There were five males and two females aged from 36 to 53 years (mean 45 years). Maxilla was more affected than mandibles (6:1). Radiographically, all cases showed multilocular radiolucencies with well-defined borders. Histologically, lining epithelium of GOC was composed of nonkeratinized stratified epithelial cells with focal plaque-like or whirl pool-like thickenings. Surface epithelial layer contained eosinophilic cuboidal cells or mucous cells. Mucin pools of microcystic areas was also detected in the epithelium. Immunohistochemical study demonstrated that epithelium of GOCs was positively reactive for CK 5 7, 14 and CK-pan with a slight variation in their patterns and there was no reaction for CK 18.