Diagnostic usefulness of panoramic imaging of the pterygopalatine fossa: case of a schwannoma causing pterygopalatine fossa expansion.

The pterygopalatine fossa is a small area between the posterior wall of the maxillary sinus and the anterior surface of the pterygoid process of the sphenoid bone. The pterygopalatine fossa can be seen clearly on panoramic imaging. We present the case of a 57-year-old man who exhibited right pterygopalatine fossa expansion on panoramic imaging. Computed tomography (CT), magnetic resonance imaging (MRI), and panoramic imaging all showed a tumor at the right pterygopalatine fossa in this patient. CT indicated that the tumor replaced right retromaxillary fat and displaced the posterior wall of the maxillary sinus. On MRI, the tumor showed intermediate signal intensity at the paranasal area on T1-weighted images, and variable intermediate and high signal intensities on fat-suppressed T2-weighted images. It was eventually diagnosed as a schwannoma. Thus, panoramic imaging can be used for disease screening at the posterior border of the maxilla. Our conclusion is based on this report of a patient with a schwannoma at the posterior wall of the maxillary sinus, which panoramic imaging revealed to have pterygopalatine fossa expansion.

Calcifying cystic odontogenic tumor accompanied by a dentigerous cyst: A case report.

A calcifying cystic odontogenic tumor (CCOT) is a proliferation of odontogenic epithelium and scattered nests of ghost cells and calcifications that may form the lining of a cyst, or present as a solid mass. It was previously described by Gorlin et al in 1962 as a calcifying odontogenic cyst. Dentigerous cysts are developmental odontogenic jaw cysts, commonly manifesting in the second and third decades of life. The present study reports an asymptomatic case in a 13-year-old boy who was referred to the outpatient clinic of the Osaka Dental University Hospital (Osaka, Japan) for additional investigation of an area of radiolucency in the lower right jaw. X-ray demonstrated a unilocular, well-circumscribed, radiolucent lesion in the mandible, which measured 30×20 mm, with radiopaque structures within it. Enucleation of the lesion with tooth extraction was performed, which histopathologically revealed features of a CCOT and a cyst. To the best of our knowledge, the occurrence of such a lesion has not been previously identified. The present study examined the significance of the case with a brief review of the literature.

Differential expression of the epithelial mesenchymal transition factors Snail, Slug, Twist, TGF-ß, and E-cadherin in ameloblastoma.

Epithelial mesenchymal transition (EMT), the transition of epithelial cells into motile mesenchymal cells, plays an important role in embryogenesis, cancer invasion, and metastasis. Ameloblastomas are common epithelial odontogenic tumors, occurring exclusively in the mandible with locally invasive growth. Thirty-seven ameloblastoma cases were evaluated for the involvement of EMT by immunohistochemical staining and western blotting using antibodies against Slug, Snail, Twist, TGF-ß, and E-cadherin. Double immunostaining was also performed. Slug and TGF-ß were expressed in the nuclei of peripheral and stellate reticulum cells of ameloblastoma nests. Twenty cases of Snail, 36 of Slug, 8 of Twist, and 19 of TGF-ß showed strong expression in tumor cells in follicular and plexiform patterns. Expression of Slug and TGF-ß increased in regions where the expression of E-cadherin was reduced. EMT was found to be associated with the local invasive growth of ameloblastoma. These data suggest that reduced expression of E-cadherin and over-expression of Slug, Snail, and TGF-ß induce EMT. Given that ameloblastomas are characterized by local invasiveness, EMT might be related to their development. Thus, strong expression of Slug and TGF-ß and reduced expression of E-cadherin might be related to the local invasiveness of ameloblastoma.

The role of computed tomography and magnetic resonance imaging in diagnosing clear cell ameloblastoma: A case report.

Ameloblastoma is the most common and clinically relevant type of odontogenic tumor. Clear cell odontogenic carcinoma is histologically characterized by solid sheets and nests of clear cells, whereas clear cell ameloblastoma (CCAM) is histologically characterized by an ameloblastomatous component intermixed with an extensive clear cell component. A total of 12 reports have been published on the histological etiology for CCAM; however, no reports have made regarding the detailed computed tomography and/or magnetic resonance imaging features of tumors of this type. The present study describes a case of a well-circumscribed 20-mm radiolucent lesion of the anterior mandible that was misdiagnosed as a clear cell odontogenic carcinoma. The study describes the detailed radiological characteristics of a case of CCAM.

Papillary oncocytic cystadenoma of a palatal minor salivary gland: A case report.

Papillary cystadenomas of the salivary gland are uncommon, benign, encapsulated or well-circumscribed, multicystic tumors with intracystic papillations. In a large review, papillary cystadenoma constituted 2% of all minor salivary gland tumors. The present study reports an extremely rare case of a papillary cystadenoma arising from the palate that demonstrated oncocytic features. A 60-year-old man was referred by his dentist to the Second Department of Oral and Maxillofacial Surgery at Osaka Dental University Hospital for the diagnostic evaluation of a mass of the left palate. An incisional biopsy was performed and the microscopic findings were interpreted as consistent with a papillary oncocytic cystadenoma. Therefore, the lesion was excised under general anesthesia. The post-operative course was uneventful and no recurrence had developed 5 years subsequent to surgery.

A rare case of amelanotic malignant melanoma in the oral region: Clinical investigation and immunohistochemical study.

Amelanotic malignant melanoma (AMM) is rare in the oral region. The present study examined the clinical features of this tumor in an attempt to establish diagnostic criteria. The expression of three melanocytic differentiation markers, HMB-45, S-100 and Melan-A, was also measured in primary oral AMMs in order to determine whether the markers could be used to diagnose primary oral AMMs and to find out which marker was the most sensitive. It may be particularly difficult to correctly diagnose AMM that lacks a radial growth phase without immunohistochemical assistance. In the present study, mixtures of polygonal and spindle cells at different ratios were observed in the tumors with and without a radial growth phase. Immunohistochemistry was used to examine the HMB-45, S-100 and Melan-A expression in the formalin-fixed paraffin-embedded specimens of primary oral AMMs. Comparison of staining intensities (SIs) and labeling indices (LIs) of the markers was also performed. The immunostaining results revealed that the SI of Melan-A was significantly higher than that of S-100 (P=0.0011). HMB-45, S-100 and Melan-A also exhibited high positive rates and LIs in AMMs and, therefore, may be good markers for the immunohistochemical diagnosis of primary oral AMMs. Furthermore, Melan-A may be a more sensitive marker than S-100 and HMB-45, as it has a higher SI.

Cyclin D1 expression is correlated with cell differentiation and cell proliferation in oral squamous cell carcinomas.

The present study conducted an immunohistochemical investigation of cyclin D1 and Ki-67 expression in oral squamous cell carcinoma (SCC) to evaluate the correlations between cell differentiation, cell proliferation and metastasis, and the effect of anticancer drug medication and cyclin D1 expression. Cyclin D1 and Ki-67 were detected clearly in the nuclei of 35 SCC samples. No correlation between cyclin D1 protein expression and oral SCC differentiation was found. By contrast, the majority of metastatic foci (90%) exhibited strong cyclin D1 expression, whereas weak expression was observed in metastatic foci with pre-operative adjuvant therapy. Additionally, cyclin D1 and Ki-67 were expressed in basal to suprabasal cells of well-differentiated oral SCC, whereas cyclin D1-positive and Ki-67-negative cells were present in the highly-differentiated region, according to a double-immunostaining method. These results indicate that the expression of cyclin D1 protein plays a role in cell differentiation and cell proliferation in well-differentiated oral SCC.

The expression of cytokeratin in keratocystic odontogenic tumor, orthokeratinized odontogenic cyst, dentigerous cyst, radicular cyst and dermoid cyst.

The epithelial lining of odontogenic keratocysts exhibits either parakeratosis or orthokeratosis. In 2005, the WHO classified odontogenic keratocysts with parakeratosis as keratocystic odontogenic tumors (KCOT). Odontogenic keratocysts with orthokeratosis were not classified as odontogenic tumors, but instead referred to as orthokeratinized odontogenic cysts (OOC). To clarify the difference between these two lesions, we investigated their biological characteristics using immunohistochemical studies for cytokeratins (CK) in KCOT and OOC as well as in dentigerous cysts (DC), radicular cysts (RC) and dermoid cysts (DMC). We examined twenty-five cases of KCOT, fifteen cases each of OOC, DC and RC, and ten cases of DMC. We studied the immunohistochemical expression of CK10, 13, 17 and 19. To evaluate the immunohistochemical staining pattern, we divided the epithelial lining of the lesions into three layers (surface layer: su, spinous layer: sp, basal layer: ba). For CK10, most OOC and DMC specimens of su and sp were positive. For CK13 and 19, most KCOT, DC and RC specimens of su and sp were positive. For CK17, most KCOT specimens of su and sp were positive. The percentages of total CK expression of su and sp, and ba of CK19 differed significantly between the lesions (P < 0.001). These results support the hypothesis that OOC originate from not the odontogenic apparatus, but the oral epithelial component.

SOX4 expression is closely associated with differentiation and lymph node metastasis in oral squamous cell carcinoma.

SOX4 is a member of the SOX family of transcription regulators. In recent years, SOX4 was shown to be overexpressed in cancers of various organs and related to epithelial-mesenchymal transition, which is a metastatic factor. This study was the first to investigate correlations between SOX4 expression levels and the clinicopathologic factors of oral squamous cell carcinoma (OSCC). We analyzed SOX4 expression levels in 50 patients with OSCC using immunohistochemistry. All samples expressed the SOX4 protein and elevated SOX4 expression was significantly correlated with gender, T status, and stage levels. The expression level of SOX4 in primary foci of poorly differentiated OSCC was higher than that of well differentiated OSCC, which indicated that SOX4 expression is associated with the differentiation of OSCC. However, regardless of the differentiation level in the primary focus, SOX4 expression levels were found to be very high in the metastatic focus. Furthermore, SOX4 expression in metastatic foci was significantly suppressed by neoadjuvant therapy. These results indicate that undifferentiated OSCC cells expressing SOX4 are more likely to metastasize and neoadjuvant therapy including chemoradiation therapy may have some effect in metastatic prevention.

NANOG expression correlates with differentiation, metastasis and resistance to preoperative adjuvant therapy in oral squamous cell carcinoma.

NANOG protein, a transcription factor expressed in embryonic stem cells, is overexpressed in tumor development. Although studies investigating the function of NANOG in cancer have shown that it plays several roles, such as in cell proliferation, invasion and metastasis, the overall function of NANOG in cancer cells has remained elusive. In the present study, NANOG expression in oral squamous cell carcinoma (OSCC) was examined to determine its potential clinical significance. The expression of NANOG protein was assessed in 60 patients with OSCC by immunohistochemistry, and its correlation with clinicopathological factors and metastasis was evaluated. NANOG protein levels in human OSCC cell lines were determined by western blotting and immunofluorescence staining. NANOG protein expression was identified in 52 cases (86.7%) and expression levels were higher in primary foci of poorly differentiated OSCC than in those of well-differentiated OSCC, indicating that NANOG expression is associated with OSCC differentiation. Regardless of the differentiation levels of primary foci, NANOG expression levels in metastatic foci were extremely high. In addition, NANOG expression in metastatic foci was maintained at high levels following preoperative adjuvant therapy. Furthermore, NANOG protein was detected at an identical level in human OSCC cell lines. These data indicate that NANOG-expressing OSCC cells tend to metastasize and that metastatic tumors expressing NANOG may be resistant to preoperative adjuvant therapy, including chemoradiation. Thus, assessment of NANOG expression may assist the strategy for treatment of OSCC metastasis.

Preliminary report of Ki-67 reactivity in synovial chondromatosis of the temporomandibular joint: an immunohistochemical study.

BACKGROUND: Synovial chondromatosis (SC) is rare benign condition characterized by the formation of metaplastic cartilaginous nodules in the synovial membrane and joint space. Cartilaginous nodules from and may become pedunculated and detached from the synovial membrane, so becoming loose bodies within the joint space. PURPOSE: The aim of this study was to determine the proliferative activity of loose body and synovial membrane of SC in temporomandibular joint by using Ki-67 antibody. MATERIAL AND METHODS: We obtained 4 specimens (4 female) of released loose body and 2 specimens of synovial membrane with attached loose bodies by surgical operation. The specimens were fixed in 10% formalin solution, and embedded in paraffin. The immunohistochemical study was carried out using an anti-human Ki-67 monoclonal antibody. The sections were visualized by 3, 3'-diaminobenzidine-tetrahydrochloride (DAB). RESULTS: The expression of Ki-67 was scarcely detected in all cases of loose bodies. In second phase cases, the mild expression of Ki-67 was detected at both cases of synovial membrane which were attached loose bodies. CONCLUSION: These results suggested that released loose bodies into the joint compartment did not have independent proliferating activity. However, the synovial membrane may play a very important role in the proliferation of the loose bodies.

CD56 expression is associated with neuroectodermal differentiation in ameloblastomas: an immunohistochemical evaluation in comparison with odontogenic cystic lesions.

Ameloblastoma (AB), which is the most common odontogenic tumor, may originate from the dental lamina remnants. The expression of CD56, which is a transmembrane molecule, is associated with neuroectodermal differentiation of the embryonal cells. The aim of this study was to evaluate the expression of CD56 in AB, in comparison with other odontogenic cysts. We used formalin-fixed, paraffi n-embedded specimens from 34 cases of AB, 10 cases of keratocystic odontogenic tumor (KCOT), and 7 cases of dentigerous cyst (DC). We immunohistochemically examined CD56, NeuroD1, and N-cadherin expression in these tumors as compared with the expression patterns of various epithelial markers. Seventy-four percent of AB showed immunopositivity for CD56, and both CD56 and N-cadherin were diffusely positive in the outer columnar cells of AB. The immunopositivities for NeuroD1 and N-cadherin were also observed in the outer cells of AB. None of the DC cases was positive for CD56, whereas half the cases of KCOT were positive. Because CD56 is expressed in the inner enamel epithelium of enamel organs, the outer columnar cells of AB are likely to be the differentiation phenotype of the inner enamel epithelium, which is associated with neuroectodermal differentiation. The aberrant NeuroD1 expression may induce CD56 expression in AB and KCOT.

P-selectin glycoprotein ligand-1 mediates L-selectin-independent leukocyte rolling in high endothelial venules of peripheral lymph nodes.

Lymphocyte homing to peripheral lymph nodes (LNs) requires L-selectin. Previous studies, however, suggest that there are L-selectin-independent mechanisms of lymphocyte homing. P-selectin glycoprotein ligand-1 (PSGL-1) is a major ligand for P-selectin expressed in a selectin-binding form on myeloid cells and subsets of lymphoid cells. To discover whether PSGL-1 plays a role in lymphocyte homing, we examined leukocyte rolling and adhesion in the high endothelial venules (HEVs) of the subiliac LNs of wild-type and PSGL-1-deficient mice by intravital microscopy. There were no significant differences in blood velocity or wall shear stress between wild-type and PSGL-1-deficient mice. Although the leukocyte rolling fraction was not altered in PSGL-1-deficient mice, infusion of an anti-L-selectin mAb into these mice completely abolished leukocyte rolling, while the same treatment in wild-type mice inhibited 90% of the leukocyte rolling. This residual rolling in wild-type mice appears to depend on the PSGL-1-P-selectin interaction, since infusion of an anti-L-selectin mAb together with an anti-PSGL-1 mAb or anti-P-selectin mAb almost completely abolished the rolling. PSGL-1 deficiency also led to a higher rolling velocity, suggesting that PSGL-1 mediates leukocyte rolling at low velocities. P-selectin was found to be expressed on the HEVs of subiliac LNs under the conditions of intravital microscopy. Taken together, these results indicate that the interaction of PSGL-1 with P-selectin constitutes a second mechanism of leukocyte rolling in the HEVs of peripheral LNs.

Immunohistochemical co-localization of lymphatics and blood vessels in oral squamous cell carcinomas.

BACKGROUND: Differentiating lymphatic vessels from blood vessels is difficult, partly due to the lack of a specific method for identifying lymphatics. A new lymphatic vessel-reactive antibody, D2-40 has recently become commercially available. We examined the selectivity of D2-40 for lymphatics in oral neoplastic lesions for discrimination from blood vessels. METHODS: Formalin-fixed, paraffin-embedded sections of oral lymphangiomas (n = 3), oral hemangiomas (n = 7), and oral squamous cell carcinomas (OSCC, n = 46) were double immunostained with D2-40 and anti-CD34 monoclonal antibodies (MoAb) using ENVISION-polymer technique with 5-bromo-4-chloro-3-indoxyl-phosphate (BCIP)/nitroblue tetrazolium chloride (NBT) and 3,3'-diaminobenzidine (DAB) as color reagents, respectively. RESULTS: In the oral lymphangiomas and hemangiomas D2-40 was detected in all lymphatics, while all blood vessels were positive for CD34. In OSCC, number of vessels for lymphatics (P < 0.01) and for blood vessels in the perineoplastic areas were significantly greater than those in intratumoral areas. CONCLUSIONS: These results indicate that lymphatic proliferation might be much more extensive in the peritumoral area than intratumoral.

Marker of cemento-periodontal ligament junction associated with periodontal regeneration.

OBJECTIVE: The purpose of this study was to identify factors promoting formation of the cemento-periodontal ligament junction. BACKGROUND: Regeneration of the cemento-periodontal ligament junction is an important factor in recovery of the connective tissue attachment to the cementum and it is important to identify all specific substances that promote its formation. To clarify the substances involved in cemento-periodontal ligament junction formation, we produced a monoclonal antibody (mAb) to human cemento-periodontal ligament junction (designated as the anti-TAP mAb) and examined its immunostaining properties and reactive antigen. METHODS: Hybridomas producing monoclonal antibody against human cemento-periodontal ligament junction antigens were established by fusing P3U1 mouse myeloma cells with spleen cells from BALB/c mice immunized with homogenized human cemento-periodontal ligament junction. The mAb, the anti-TAP mAb for cemento-periodontal ligament junction, was then isolated. The immunoglobulin class and light chain of the mAb were examined using an isotyping kit. Before immunostaining, antigen determination using an enzymatic method or heating was conducted. Human teeth, hard tissue-forming lesions, and animal tissues were immunostained by the anti-TAP mAb. RESULTS: The anti-TAP mAb was positive in human cemento-periodontal ligament junction and predentin but negative in all other human and animal tissues examined. In the cemento-osseous lesions, the anti-TAP mAb was positive in the peripheral area of the cementum and cementum-like hard tissues and not in the bone and bone-like tissues. The anti-TAP mAb showed IgM (kappa) and recognized phosphoprotein. CONCLUSION: The anti-TAP mAb is potentially useful for developing new agents promoting cementogenesis and periodontal regeneration.