Ghost cell odontogenic carcinoma arising in dentinogenic ghost cell tumor, peripheral: A case report

Ghost cell odontogenic carcinoma (GCOC) is an extremely rare intraosseous malignant odontogenic tumor with prominent ghost cell keratinization and dentinoid formation. Here, we present the first case of GCOC arising in dentinogenic ghost cell tumor (DGCT), peripheral. The patient was a man in his 60s with an exophytic mass in the anterior part of lower gingiva. The resected tumor measured 4.5 cm in maximum diameter. Histologically, the nonencapsulated tumor proliferated in the gingiva without bone invasion. It was predominantly composed of ameloblastoma-like nests and islands of basaloid cells with ghost cells and dentinoid in the mature connective tissue, suggesting DGCT, peripheral. As minor components, sheets of atypical basaloid cells and ameloblastic carcinoma-like nests with pleomorphism and high proliferative activity (Ki-67 labeling index up to 40%) consistent with malignancy were identified. CTNNB1 mutation and β-catenin nuclear translocation were observed in both benign and malignant components. Final diagnosis was GCOC arising in DGCT, peripheral. GCOC shows similar histological features to DGCT. In this unique case without invasion, the cytological atypia and high proliferative activity supports the diagnosis of malignant transformation from DGCT.

Importance of anti-centromere antibodies in the diagnosis of Sjögren's syndrome

The purpose of the present study was to indicate that patients with anti-centromere antibodies (ACA) also experience ocular/oral dryness like patients with anti-Ro/SSA and/or anti-La/SSB antibodies (anti-SSA/SSB). A total of 80 patients with subjective ocular and/or oral dryness were classified into two groups, namely, anti-SSA/SSB-positive (anti-SSA/SSB [+]) group and ACA-positive (ACA [+]) group. The degree of ocular and oral dryness in ACA (+) patients is similar to that in anti-SSA/SSB (+) patients. On histopathological examination of the labial glands, the area of fibrosis was significantly larger in the ACA (+) group than in the anti-SSA/SSB (+) group. Thus, ACA (+) patients should be examined for Sjögren's syndrome.

Salivary Gland Polymorphous Adenocarcinoma: Clinicopathological Features and Gene Alterations in 36 Japanese Patients

OBJECTIVES

Polymorphous adenocarcinoma (PAC) is a common intraoral minor salivary gland carcinoma in Western countries but is extremely rare in Japan. The current study aimed to characterize the clinicopathological features and status of molecular alterations of PAC-associated genes, such as (e.g., PRKD1/2/3, ARID1A, and DDX3X) in a large cohort of Japanese patients with PAC.

MATERIALS AND METHODS

We examined the cases of 36 Japanese patients with salivary gland PAC and 26 cases involving histopathological mimics. To detect gene splits, fluorescence in situ hybridization was carried out for PAC-associated genes. Additionally, we applied a SNaPshot multiplex assay to identify PRKD1 hotspot mutations.

RESULTS

This study revealed the indolent clinical course of PAC with a high 10-year overall survival rate (92.9%), accompanied by occasional local recurrences and cervical lymph node metastasis (both 23.3%). Twenty cases (55.6%) of PAC (but none of the mimics) exhibited alterations in at least one PAC-associated gene. Rearrangement of PAC-associated genes and PRKD1 E710D were identified in 17 (47.2%) and 4 (11.1%) cases, respectively; one case showed coexisting PRKD3 split and PRKD1 E710D. In the multivariate analysis, high clinical stage (P=0.0005), the presence of prominent nucleoli (P=0.0003), and ARID1A split positivity (P=0.004) were independent risk factors for disease-free survival.

CONCLUSION

Japanese patients with PAC showed clinicopathological features similar to those reported in Western countries. This study disclosed that PAC-associated genetic alterations were common and specific findings in PACs. The diagnostic role and possible prognostic significance of PAC-associated genetic alterations in PACs were suggested.

Non-sebaceous lymphadenoma-like mucoepidermoid carcinoma: A case report

Non-sebaceous lymphadenoma is a rare benign salivary gland tumor comprised of non-sebaceous epithelial cells and lymphoid tissue. Although its clinicopathological features have been described, its histogenesis and genetic background have not yet been elucidated. MAML2 rearrangement and the resultant CRTC1/3-MAML2 fusion gene are well-known specific genetic changes in mucoepidermoid carcinoma. Here, we present a case of lymphoepithelial tumor characterized by histomorphology of the non-sebaceous lymphadenoma and CRTC1-MAML2 fusion gene. The patient was an 83-year-old woman with an 8-year history of a solid, well-circumscribed tumor in the parotid gland. Histologically, the tumor was surrounded by thin fibrous connective tissue and was composed of tubular-cystic and solid nests of epithelial cells equally distributed in the lymphoid tissue. The histological features were suggestive of non-sebaceous lymphadenoma. Although the histomorphology was not consistent with mucoepidermoid carcinoma, a diagnosis of non-sebaceous lymphadenoma-like mucoepidermoid carcinoma was made based on the presence of the CRTC1-MAML2 fusion gene. The histological features alone could not establish the diagnosis, and ancillary molecular analysis was required.

Two Cases of Temporomandibular Synovial Chondromatosis Associated with Gli1 Gene Mutation

Synovial chondromatosis (SC) is a rare benign disease involving multifocal generation of ectopic cartilage in the synovial tissue. Herein, we report two cases of SC in the temporomandibular joint: a 38-year-old woman (patient 1) and 39-year-old woman (patient 2). Both patients had trismus, jaw joint noises, and jaw-opening pain in the temporomandibular joint. Cone-beam computed tomography (CT) and magnetic resonance imaging (MRI) in patient 1 showed multiple calcified loose bodies around the right mandibular condyle. In addition, CT and MRI in patient 2 showed multiple calcified loose bodies around the left mandibular condyle and temporal bone perforation. Following establishing a diagnosis of SC, both patients underwent tumor resection via open surgery. In immunohistochemical examinations of the resected tissues, tumor cells showed intense nuclear staining with labeled anti-Gli1 antibody. Gene sequencing revealed that both patients had a homozygous mutation in the Gli1 gene (rs2228226 G>C). In conclusion, we suggest that the Gli1 gene (rs2228226 G>C) may be involved in the etiology of SC.

Activating HRAS mutation in a case of inverted ductal papilloma of the salivary gland

Inverted ductal papilloma (IDP) is one of the least common benign papillary/cystic neoplasms of the salivary duct system, being characterized histologically by florid hyperplasia of duct-type epithelial cells into a cystic lumen near the orifice with occasional endophytic growth of the surface squamous epithelium along the terminus of the affected excretory duct. Given its rarity, the exact etiology of IDP remains to be defined. We herein present the first evidence of oncogenic HRAS mutation in a case of oral IDP. This finding, together with the frequent and specific BRAF mutations in sialadenoma papilliferum reported in the recent literature, supports an active role of the MAP-kinase cascade in the pathogenesis of benign papillary neoplasms of terminal duct origin.

Relationships between intraoral ultrasonographic and histopathological findings in patients with tongue cancer

BACKGROUND

In this study, we aimed to investigate the relationships between histopathological and intraoral ultrasonographic (IUS) findings in patients with tongue cancer.

METHODS

IUS and histopathological findings in 46 patients with tongue cancer were considered for this study. We assessed the relationships between IUS findings regarding tumor thickness, margin type, border type, and internal echo intensity; internal/peripheral Doppler findings; and muscle invasion and histopathological findings regarding tumor thickness, differentiation, Yamamoto-Kohama (YK)-classification grade, blood vessel invasion, lymphatic invasion, perineural invasion, and muscle invasion.

RESULTS

Statistical associations were found between the following findings: between thickness determined through IUS measurement and that determined through histopathological measurement, between the IUS findings regarding tumor margin and border types and the histopathologically determined YK-classifications grades, and between a Doppler image of the internal area of tongue lesions and lymphatic invasion.

CONCLUSIONS

IUS findings may be used to predict histopathological findings about tumor thickness and YK-classification grades.

Oncocytic Polyp in a Unicystic Mucoepidermoid Carcinoma of the Palate: A Unique Presentation

We report a palatal mucoepidermoid carcinoma (MEC) with unusual pathological features showing salivary duct cyst-like architecture, varied epithelial linings (excretory duct, mucous goblet cell, and apocrine epithelium phenotypes), scarce luminal tumor plaques, and a large intraluminal oncocytic polyp. To our knowledge, such a unicystic variant of MEC with pedicled oncocytic proliferation in the lumen is unprecedented in the literature. In this particular case, the microscopic diagnosis of MEC is problematic because of the large number of potential mimics.

Sialadenoma Papilliferum of the Bronchus: An Unrecognized Bronchial Counterpart of the Salivary Gland Tumor With Frequent BRAF V600E Mutations

Sialadenoma papilliferum (SP) is a rare benign tumor of the salivary glands, and only 3 unequivocal cases of SP arising in the bronchus have been reported. We herein describe the histomorphologic and molecular features of 4 bronchial SP cases and discuss the differential diagnosis of this entity and the relationship with its clinicopathologic mimics, in particular, glandular papilloma and mixed squamous cell and glandular papilloma (GP/MP). We encountered 2 male and 2 female patients with bronchial SP (mean: 66.8 y old). All 4 tumors arose in the central bronchus and were characterized by a combination of surface exophytic endobronchial papillary proliferation and a submucosal multicystic component with complex architecture. The neoplastic epithelium consisted predominantly of nonciliated stratified columnar cells with ciliated, squamous, and mucinous cells present focally. While 2 tumors (50%) harbored a BRAF V600E mutation by molecular and immunohistochemical analysis, similar to GP/MP, no KRAS, HRAS, AKT1, or PIK3CA mutations were detected in any of the cases. Two patients were treated with limited resection, while 2 patients underwent lobectomy based on the diagnosis of adenocarcinoma or possible squamous cell carcinoma in situ in the preoperative biopsy. All survived without recurrence or metastasis for 23 to 122 months after treatment. SP can develop in the central bronchus as the bronchial counterpart of the salivary gland tumor and should be considered in the differential diagnosis of endobronchial tumors. In addition, some histologic resemblance and frequent BRAF V600E mutation raise the possibility of SP and GP/MP being on the same disease spectrum.

Lead-free MCP to improve coincidence time resolution and reduce MCP direct interactions

Achieving direct imaging of the annihilation position of a positron on an event-by-event basis using an ultrafast detector would have a great impact on the field of nuclear medicine. Cherenkov emission is the most attractive physical phenomenon for realizing such an ultrafast timing performance. Moreover, a microchannel-plate photomultiplier tube (MCP-PMT) is one of the most promising photodetectors for fully exploiting the fast timing properties of Cherenkov emission owing to its excellent single photon time resolution of 25 ps full width at half maximum (FWHM). However, as the MCP structure generally contains a lead compound, the gamma rays frequently and directly interact with the MCP, resulting in the degradation of its timing performance and generation of undesirable side peaks in its coincidence timing histogram. To overcome this problem, we have developed a new MCP-PMT based on an MCP consisting of borosilicate glass, thus drastically reducing the probability of the photoelectric effect occurring in the MCP. To evaluate its insensitivity to gamma rays and its timing performance, a coincidence experiment was performed and showed that the probability of direct interactions was reduced by a factor of 3.4. Moreover, a coincidence time resolution of 35.4 ± 0.4 ps FWHM, which is equivalent to a position resolution of 5.31 mm, was obtained without any pulse height/area cut, improving to 28.7 ± 3.0 ps when selecting on the highest amplitude events by careful optimization of the voltage divider circuit of the new MCP-PMT. The timing performance of this new MCP-PMT presents an important step toward making direct imaging possible.

Homeobox transcription factor engrailed homeobox 1 is a possible diagnostic marker for adenoid cystic carcinoma and polymorphous adenocarcinoma

Diagnostic utility of a homeobox transcription factor, engrailed homeobox 1 (En1) in the histopathology of salivary gland neoplasms was studied. The expression of En1 was immunohistochemically examined in 51 cases of adenoid cystic carcinoma (AdCC) and 143 cases of other salivary gland neoplasms. In all 51 AdCCs, En1 was expressed in 30-100% of tumor cells. In eight of nine polymorphous adenocarcinomas (PACs), En1 was expressed in 40-100% of tumor cells. Less than 5% of tumor cells expressed En1 in three of 12 epithelial-myoepithelial carcinomas, one of 17 basal cell adenomas (BCAs), and one of 34 pleomorphic adenomas (PAs). Among 55 other carcinoma cases, 1-30% of tumor cells expressed En1 in three salivary duct carcinomas (SDCs) ex PA. None of the myoepitheliomas and Warthin tumors expressed En1. When the cut-off value of the percentage of En1-expressing cells was set to 25%, all 51 AdCCs, eight of nine PACs and one SDC ex PA were En1-positive and the others were En1-negative. En1 is expressed consistently in AdCCs, frequently in PACs, but rarely in other salivary gland neoplasms. En1 is a possible diagnostic marker for AdCC and PAC in the histopathology of salivary gland neoplasms.

Rapid detection of the Streptococcus mutans cnm gene by loop-mediated isothermal amplification

This study investigated a method using loop-mediated isothermal amplification (LAMP) for the rapid detection of cnm-positive Streptococcus mutans (S. mutans) associated with cerebral microhemorrhage. LAMP amplified the cnm gene plasmid vector, but not human or microbial genomic DNA. The cnm DNA of the cnm-positive S. mutans strain was detected in saliva without DNA extraction after 1 day of culture. This method resulted in a cnm-positive rate of 26.4% in 102 samples, which was higher than that obtained with conventional PCR. In conclusion, LAMP may be used for the detection of cnm-positive S. mutans in a large number of samples.

The transition of tissue inhibitor of metalloproteinases from -4 to -1 induces aggressive behavior and poor patient survival in dedifferentiated liposarcoma via YAP/TAZ activation

Liposarcoma (LS) is the most common soft-tissue sarcoma. Dedifferentiated liposarcoma (DDLS) shows more aggressive biological behavior than that of well-differentiated liposarcoma (WDLS), so advanced therapeutic agents based on molecular mechanism are urgently needed. Here we show that tissue inhibitors of metalloproteinases (TIMPs) from TIMP-1 to TIMP-4 are differently expressed and regulate yes-associated protein (YAP)/transcriptional co-activator with PDZ binding motif (TAZ) in LS. Database analysis showed high TIMP-1 expression in DDLS patients correlating with poor prognosis, but high TIMP-4 expression in WDLS patients with better prognosis. Stable TIMP-1 knockdown inactivated YAP/TAZ and inhibited proliferation, colony formation and migration in DDLS cells, which was rescued by a constitutive active YAP. However, stable overexpression of TIMP-1 showed the opposite in WDLS cells. Stable TIMP-4 knockdown activated YAP/TAZ and promoted proliferation and migration in WDLS cells, which was suppressed by YAP/TAZ inhibitor (verteporfin) or knockdown of YAP/TAZ. Recombinant TIMP-4 showed opposite results in DDLS cells. These results indicate that dedifferentiation in LS shifts the expression of TIMPs from type 4 to type 1, inducing more aggressive behavior and poor prognosis through YAP/TAZ activation, which can be prognostic markers and therapeutic targets for LS patients.

Oral environment and taste function of Japanese HIV-infected patients treated with antiretroviral therapy

The aim of the study was to evaluate the oral environment and the taste function of Japanese HIV-infected patients treated with antiretroviral therapy. Their median age of 73 patients taking anti-HIV drugs was 46 years. The median period of taking anti-HIV drugs was 30 months. The oral condition was evaluated by measurement of oral moisture, amount of saliva secretion, the number of oral bacteria, presence of oral candida, a taste test, and the number of missing teeth. The levels of oral moisture and secreted saliva were significantly lower in the HIV-infected group than in the healthy volunteer (control) group. The HIV-infected group showed a more robust decrease in taste sensation than the control group. The number of missing teeth was significantly higher in the HIV-infected group than in the control group. Furthermore, all of the evaluated oral conditions were worse in the HIV-infected patients whose CD4+ T lymphocyte counts were less than 500/mm³ than in the control group. It became clear that the patients taking anti-HIV drugs, especially the CD4+ count < 500/mm3 group, had a deteriorated oral environment and dysgeusia, suggesting that the management of oral hygiene is necessary to maintain oral health, which leads to systemic health.

Characteristics of 5015 Salivary Gland Neoplasms Registered in the Hiroshima Tumor Tissue Registry over a Period of 39 Years

Salivary gland neoplasms are uncommon, and their epidemiology in Japan has not been well described. We conducted a retrospective review of salivary gland tumors registered in the Hiroshima Tumor Tissue Registry over a period of 39 years. The subjects were 5015 cases ranging in age from 6 to 97 (mean, 54.3) years old. The incidence of both benign tumors and malignant tumors increased with age until 60-69 years and then declined. Among the 5015 salivary gland neoplasms, 3998 (80%) were benign and 1017 (20%) were malignant. Pleomorphic adenoma (PA) was the most frequent benign tumor (68%), followed by Warthin tumor (26%). Adenoid cystic carcinoma (ACC) (27%) and mucoepidermoid carcinoma (MEC) (26%) were the two most frequent malignant tumors. Characteristically, there was a very low incidence of polymorphous adenocarcinoma in Japan. The average annual age-adjusted incidence rate per 100,000 population was 3.3 for benign tumors and 0.8 for malignant tumors. This is the large-scale multi-institutional analysis to describe the characteristics of salivary gland neoplasms, based on the pathological tissue registry data. We hope that the present data can contribute to early diagnosis and effective treatment of salivary gland tumors and to cancer prevention.

Detection of MAPK/ERK pathway proteins and KRAS mutations in adenomatoid odontogenic tumors

OBJECTIVE

This study aimed to assess the frequency of KRAS mutation and its association with the presence of the MAPK/ERK signaling pathway proteins in adenomatoid odontogenic tumors.

STUDY DESIGN

Paraffin-embedded tissue samples from nine cases of adenomatoid odontogenic tumor were used. Genomic DNA was extracted from each sample; in one case, genetic mutations in 50 cancer-associated genes were examined by next-generation sequencing. Hotspot mutations in the RAS family were analyzed by Luminex assay using the remaining eight cases. Subsequently, immunohistochemistry for KRAS, CRAF, BRAF, EGFR, ERK, MEK, and BRAFV600E was performed.

RESULTS

A KRAS G12D missense mutation was detected in the DNA sequence of the tumor cells, but it was not detected in the stromal tissue. KRAS G12V and KRAS G12R mutations were detected in two and four cases, respectively. For immunohistochemistry, all the cases were EGFR, KRAS, BRAF, CRAF positive, one case was ERK negative,and one case was MEK and ERK negative, all the other remaining cases were MEK and ERK positive.

CONCLUSION

KRAS mutation at codon 12 and the presence of MAPK/ERK pathway proteins were detected suggesting their association with tumorigenesis of adenomatoid odontogenic tumors.

Current status of dental metal allergy in Japan

PURPOSE

To assess the current status of patients with dental metal allergies in Japan.

METHODS

This study analyzed dental metal allergy in 1225 patients (1:3 male to female ratio; average age 53.0 ±16.5 years), including 300 who were scheduled to undergo dental implant surgery, between 2006 and 2016. For diagnosis of metal allergy, patch tests using metal allergens were performed. Additionally, when necessary, metal element analysis of dental alloys was performed in the mouths of some patients using an X-ray fluorescence analyzer for those who exhibited positive reactions.

RESULTS

Among 925 patients (i.e., excluding those scheduled to undergo dental implant surgery [n=300]), nearly one-half (44.0%) exhibited a positive response to any metal element in the patch test. The positivity rates were as follows: nickel (22.5%); palladium (14.8%); and zinc (11.5%). Almost one-half (42.3%) of the patients had diseases associated with metal allergy. Among patients who exhibited a positive reaction to any metal element in the patch test, more than two-thirds (67.9%) had dental alloys containing the positive metal element(s). One-half (55.6%) of the patients who underwent treatment to remove the metal experienced improvement in symptoms. In patients who underwent patch testing as an implant preoperative examination, several (2.7%) exhibited a positive reaction to titanium.

CONCLUSIONS

Dental metals, including nickel, palladium and zinc, which are indispensable to dental treatment in Japan, had high positivity rates in patch testing, and one-half of the patients improved following removal of the metal. Additionally, there were several patients with allergy to titanium.

Pathogenesis of primordial odontogenic tumour based on tumourigenesis and odontogenesis

OBJECTIVE

Primordial odontogenic tumour (POT) is a rare benign mixed epithelial and mesenchymal odontogenic tumour. POT is composed of dental papilla-like tissue covered with cuboidal to columnar epithelium that resembles to inner and outer enamel epithelium of the enamel organ without dental hard tissue formation. The aim of this study was to examine pathogenesis of POT based on tumourigenesis and odontogenesis.

SUBJECTS AND METHODS

Six cases of POT were submitted for study. DNA analysis and transcriptome analysis were performed by next-generation sequencing. Expression of amelogenin, ameloblastin and dentin sialophosphoprotein (DSPP) was examined by immunohistochemistry.

RESULTS

There were no gene mutations detected in any of analysed 151 cancer- and 42 odontogenesis-associated genes. Enamel protein-coding genes of Amelx, Ambn and Enam, and dentin protein-coding genes of Col1a1, Dspp, Nes and Dmp1 were expressed, whereas expression of dentinogenesis-associated genes of Bglap, Ibsp and Nfic was negative or very weak suggesting inhibition of dentin formation in POT after odontoblast differentiation. Immunoreactivity of amelogenin, ameloblastin and DSPP was detected in POT.

CONCLUSIONS

Pathogenesis of POT is considered to be genetically different from other odontogenic tumours. It is suggested that inhibition of enamel and dentin formation in POT is due to defects in dentin formation process.

Reparative bone-like tissue formation in the tooth of a systemic sclerosis patient

AIM

To report a case of reparative bone-like tissue formation in the tooth of a patient with systemic sclerosis.

SUMMARY

A 58-year-old Japanese female patient with systemic sclerosis was referred because of tooth fracture. Cone beam computerized tomography (CBCT) revealed multiple root resorption and the unclear transition from alveolar bone to root profile. A sample from a fractured tooth was analysed histologically. Haematoxylin and eosin-stained sections revealed the irregular replacement of pulp and dentine by bone-like tissue. Calcinosis was noted in various parts of the body and a histological analysis identified it as dystrophic calcification on sclerosed fibrous connective tissue. Bite force and the occlusal area were markedly weaker than the means for female of the same age.

KEY LEARNING POINTS

CBCT may be more useful than dental radiography for diagnosing multiple root resorption in systemic sclerosis patients. When systemic sclerosis patients have calcinosis, their root status must be examined carefully. When root resorption is present in systemic sclerosis patients, reparative bone-like tissue formation in teeth needs to be taken into account prior to the initiation of dental treatment.

Central mucoepidermoid carcinoma arising from glandular odontogenic cyst confirmed by analysis of MAML2 rearrangement: A case report

Central mucoepidermoid carcinoma (MEC) poses a diagnostic challenge because of its rarity and histological overlap with glandular odontogenic cyst (GOC). In MEC of both salivary glands and jaws, MAML2 arrangement has been well known as the specific gene alteration. We report a case of central MEC arising from GOC diagnosed by MAML2 fusion gene. A 57-year-old male presented a multilocular cystic lesion in left molar region of the mandible. Histopathologically, multiple cysts lined by thin cuboidal or non-keratinized squamous epithelium with small duct-like structures, mucous cells and ciliated cells were present. It was diagnosed as GOC. The recurrent lesion after nine years showed the proliferation of many cystic and solid nests composed of epidermoid, mucous and intermediated cells. Nested PCR revealed CRTC3-MAML2 fusion gene in the recurrent lesion, but not in the primary one. Similarly, MAML-2 rearrangement by FISH analysis was positive in the recurrent lesion, while negative for the primary one, thus confirming the diagnosis of central MEC arising from GOC. Analysis of MAML2 rearrangement can be used as a supportive evidence to distinguish central MEC from GOC.

A case of primordial odontogenic tumor: A new entity in the latest WHO classification (2017)

Primordial odontogenic tumor (POT) is a rare lesion in the jaw which has been included as a new entity of benign mixed epithelial and mesenchymal odontogenic tumour in the latest World Health Organization (WHO) classification (2017). Only seven cases have been reported. It typically occurs in the posterior mandible. We report an additional case of POT in the maxilla of an 8-year-old girl presenting with an asymptomatic buccal enlargement. A well-defined, unilocular, radiolucent lesion was observed radiographically. Histologically, the tumor was mostly composed of loose fibrous connective tissue resembling dental papilla and a single layer of columnar epithelium covering the periphery of the tumor. In part, cords or nests of epithelium were present in the mesenchyme close to the periphery. Nestin, a marker of odontogenic ectomesenchyme, was positive in the mesenchymal tumor cells. We finally diagnosed the lesion as POT considering the possibility of other odontogenic tumors like ameloblastic fibroma or developing odontoma as a differential diagnosis. The patient shows no recurrence after 16 months. This case is the first report from Japan using this novel diagnosis POT after it was recognized and defined in the latest WHO classification.

microRNA-203 suppresses invasion and epithelial-mesenchymal transition induction via targeting NUAK1 in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) has a high capacity for invasion. To identify microRNAs (miRNAs) that regulate HNSCC invasion, we compared miRNA expression profiles between a parent HNSCC cell line and a highly invasive clone. The miR-200 family and miR-203 were downregulated in the clone. Here we focused on the role of miR-203 in invasion and epithelial-mesenchymal transition (EMT) induction in HNSCC. miR-203 was downregulated during EMT induction. Moreover, ectopic overexpression of miR-203 suppressed the invasion and induced mesenchymal-epithelial transition (MET) in HNSCC cells. Interestingly, we identified NUAK family SNF1-like kinase 1 (NUAK1) as a novel target gene of miR-203 by cyclopedic analysis using anti-Ago2 antibody. Increased expression of NUAK1 was observed during EMT induction, and ectopic expression of miR-203 delayed EMT induction by suppressing NUAK1 expression. Moreover, NUAK1 overexpression promoted the invasion of HNSCC cells. Importantly, NUAK1 expression was well correlated with poor differentiation, invasiveness, and lymph node metastasis in HNSCC cases. Overall, miR-203 has a tumor-suppressing role in invasion and EMT induction by targeting NUAK1 in HNSCC, suggesting miR-203 as a potential new diagnostic and therapeutic target for the treatment of HNSCC.

TNF-α-induced IL-6 and MMP-9 expression in immortalized ameloblastoma cell line established by hTERT

OBJECTIVE

Ameloblastoma (AM) shows locally invasive behaviour. However, biological investigations regarding regulation of gene expression associated with AM pathological features are difficult to perform, because AM cells can be passaged for a few generations due to senescence. We report a newly established immortalized AM cell line, AMB cells, by transfection with human telomerase reverse transcriptase (hTERT). Furthermore, we examined whether TNF-α modulates bone resorption-related genes, IL-6 and MMP-9 in cooperation with TGF-β or IFN-γ.

MATERIALS AND METHODS

Following transfection of an hTERT expression vector into AM cells using a non-viral method, the effects of cytokines on the expressions of IL-6 and MMP-9 mRNA were examined using real-time PCR. TNF-α-induced NF-κB activity was examined by western blotting and transcription factor assays.

RESULTS

AMB cells continued to grow for more than 100 population doublings. Stimulation with TNF-α increased IL-6 and MMP-9 mRNA expressions, as well as NF-κB activation. Furthermore, TGF-β and IFN-γ dramatically increased TNF-α-mediated expressions of MMP-9 and IL-6 mRNA, respectively, while those responses were suppressed by NF-κB inhibitor.

CONCLUSION

We established an immortalized AM cell line by hTERT transfection. TNF-α-mediated regulation of MMP-9 and IL-6 via NF-κB may play an important role in the pathological behaviour of AMs, such as bone resorption.

High-grade epithelial-myoepithelial carcinoma of the parotid gland with mucous cell differentiation

Epithelial-myoepithelial carcinoma (EMC) is a rare salivary gland tumor with a low-grade malignancy, and EMC with high-grade histopathological features is exceedingly rare. Furthermore, EMC with intracellular mucin is also extremely rare. We report an uncommon case of a high-grade EMC of the parotid gland with mucous cell differentiation in a 66-year old Japanese woman who noticed a right palpable parotid mass increasing in size within a one-year period. The cytological specimen showed a focally biphasic structure and included isolated or discohesive piled-up clusters with hyaline globules surrounded by neoplastic cells with nuclear atypia. The gross examination revealed a relatively well-demarcated, multinodular gray-whitish and solid mass. Histologically, the tumor consisted of variably sized solid nests or trabeculae with central necrosis and increased mitotic activity, and invaded into adjacent skeletal muscles. Immunohistochemically, the biphasic ductal and myoepithelial differentiation of this tumor confirmed the diagnosis of high-grade EMC. Furthermore, numerous small nests with d-PAS and alcian blue-positive mucous cells predominated in about 5% of the whole tumor, and these mucous cells were encompassed by neoplastic myoepithelial cells. We should recognize this variant of EMC because we can't rule out the possibility of EMC even in the presence of mucous cells.

The differential expression of mgl mRNA by Porphyromonas gingivalis affects the production of methyl mercaptan

OBJECTIVE

A large number of individuals have halitosis. The total amount of volatile sulfur compounds, which are the main cause of halitosis, has been correlated with periodontitis following bacterial infection. In this study, Porphyromonas gingivalis (Pg), a major periodontopathogenic bacterium, was isolated from patients with halitosis by the amplification of 16S rRNA, and the ability of isolated Pg to produce methyl mercaptan (CH3 SH) was determined to clarify the relationship between halitosis and Pg infection.

MATERIALS AND METHODS

CH3 SH concentrations were measured in patients using Oral Chroma. The production of CH3 SH by Pg standard and clinical strains was also measured in vitro. Real-time PCR was performed to compare the expression of mgl mRNA (which encoded l-methionine-a-deamino-g-mercaptomethane-lyase) among the Pg strains. The production of CH3 SH and the expression of mgl mRNA were also determined to assess the effects of oriental medicine.

RESULTS

The production of CH3 SH and the expression of mgl mRNA strongly correlated with each other in the presence of l-methionine. The expression of mgl mRNA by Pg W83 was strongly inhibited by magnoliaceae.

CONCLUSION

The production of CH3 SH was correlated with the expression of mgl. Furthermore, the oriental medicine, magnoliaceae, may represent a potential treatment for halitosis.

Peripheral ameloblastoma with histologically low-grade malignant features of the buccal mucosa: a case report with immunohistochemical study and genetic analysis

Peripheral ameloblastoma (PA), a rare and unusual variant of odontogenic tumors, comprises about 1% of all ameloblastomas. PA is an exophytic growth localized to the soft tissues overlying the tooth-bearing areas of the jaws, and the initial diagnosis is often fibrous epulis. PA with histologically low-grade malignant features is extremely rare. We report a case of peripheral ameloblastoma with histologically low-grade malignant features in a 69-year-old woman that presented with a hemorrhage from a tumor on the right buccal mucosa. The tumor was surgically removed by blunt dissection, with no evidence of recurrence after two years and six months. After the case presentation, microscopic and genetic findings are discussed.

Odontogenic carcinoma with dentinoid: a new odontogenic carcinoma

Dentinoid is an integral part of some odontogenic tumors. This article describes the clinico-pathological features of three cases of odontogenic carcinomas with dentinoid (OCD). A comparison of these with previously reported cases of dentinoid-producing epithelial odontogenic tumors allowed us to identify another six cases that may be considered as examples of OCD. Six cases occurred in the mandible and three in the maxilla, all developing behind the canines. There was no sex predilection (five men and four women; age range 14-61 years, mean 38.1). Pain or discomfort was mentioned in five cases, four of which showed tooth resorption. All cases appeared initially as well-defined radiolucencies, five of which showed variable amounts of calcified material. Recurrences were recorded in three instances, but no evidence of metastasis has been found. Seven cases were composed predominantly or entirely of clear cells, usually with minimal cellular atypia and variable mitotic activity; however, in all cases there was evidence of tumor infiltration into adjacent tissues, including the presence of perineural invasion in two tumors. Those cases in which no reference was made to the presence of clear cells exhibited evident mitotic activity and cellular pleomorphism. The epithelium in OCD does not produce buds or enamel organ-like structures such as those found in ameloblastic fibro-dentinoma and this tumor does not contain a mesenchyme-like connective tissue resembling dental papilla as observed in several mixed odontogenic tumors. Based on the existing data and the present series of cases, OCD appears to represent a distinct entity.

[The significance of oxidized DJ-1 protein (oxDJ-1) as a biomarker for Parkinson's disease]

The search for biomarkers of Parkinson's disease (PD) typically focuses on cerebrospinal fluid components, with very few reports on simple biomarkers identifiable by blood analysis. In this report, we determined the level of oxidized DJ-1 protein (oxDJ-1) in red blood cells by ELISA and examined the association with MIBG myocardial scintigraphy. Levels of oxDJ-1 were higher in unmedicated patients with PD (142.2 ± 21.8 ng oxDJ-1/mg protein; n = 13) compared to the L-DOPA-treated group (85.6 ± 10.1 ng oxDJ-1/mg protein; n = 10) and controls (56.0 ± 6.2 ng oxDJ-1/mg protein; n = 17), thereby showing significant intergroup differences. Intervention with L-DOPA showed a tendency to decrease oxDJ-1 levels in patients. The diagnostic sensitivity of oxDJ-1 measurement was 87% and that of simultaneously conducted MIBG scintigraphy was 89%; this showed that the diagnostic sensitivity was comparable. Our results showed that measurement of oxDJ-1 levels in red blood cells can be useful and oxDJ-1 can be used as a biomarker for the early diagnosis of PD. (Receieved July 31, 2013; Accepted October 16, 2013; Published April 1, 2014).

Malignant ossifying fibromyxoid tumor of the tongue: case report and review of the literature

Ossifying fibromyxoid tumor (OFMT) is a rare mesenchymal neoplasm that arises in subcutaneous tissue, with that in the oral cavity extremely rare. We present a case of malignant OFMT in the tongue. A 26-year-old male noticed a painless mass in the tongue, which was extracted at a general hospital. Four years later, the tumor recurred and was resected at our department. Histologically, the recurrent tumor was composed of the closely packed cells positive for vimentin and S-100 proliferating in a nodular fashion. It showed high cellularity and mitotic activity. In the primary tumor, some tumor cells were arranged in a diffuse or cord-like manner within an abundant fibromyxoid matrix, along with a small amount of metaplastic ossification, corresponding with the histopathological characteristic of OFMT. Accordingly, a diagnosis of malignant OFMT arising in typical OFMT was established. This is the first reported case of malignant OFMT in the tongue. Long-term follow-up is needed for confirmation of prognosis and biological behavior.

Selective enhancing effect of early mitotic inhibitor 1 (Emi1) depletion on the sensitivity of doxorubicin or X-ray treatment in human cancer cells

Chemotherapy and radiation in addition to surgery has proven useful in a number of different cancer types, but the effectiveness in normal tissue cannot be avoided in these therapies. To improve the effectiveness of these therapies selectively in cancer tissue is important for avoiding side effects. Early mitotic inhibitor 1 (Emi1) is known to have the function to inhibit anaphase-promoting complex/cyclosome ubiquitin ligase complex, which ubiquitylates the cell cycle-related proteins. It recently has been shown that Emi1 knockdown prevents transition from S to G2 phase by down-regulating geminin via anaphase-promoting complex/cyclosome activation. At present, anticancer drugs for targeting DNA synthesis to interfere with rapidly dividing cells commonly are used. As Emi1 depletion interferes with completion of DNA synthesis in cancer cells, we thought that Emi1 knockdown might enhance the sensitivity for anticancer agents. Here, we confirmed that Emi1 siRNA induced polyploidy for preventing transition from S to G2 phase in several cancer cell lines. Then, we treated Emi1 depleted cells with doxorubicin. Interestingly, increased apoptotic cells were observed after doxorubicin treatment in Emi1 siRNA-treated cancer cells. In addition, Emi1 depletion enhanced the sensitivity of x-ray irradiation in cancer cells. Importantly, synergistic effect of Emi1 knockdown in these combination therapies was not observed in normal cells. These results suggest that Emi1 siRNA can be a useful tool for enhancing of sensitivity of cancer cells to anticancer reagents and radiation.

Expression of receptor for hyaluronan-mediated motility (RHAMM) in ossifying fibromas

Fibro-osseous lesions of the jaw are poorly understood because of a significant overlap of clinical, radiological and histological features among the various types, though they present distinct patterns of disease progression. An ossifying fibroma is associated with significant cosmetic and functional disturbances, as it shows expansive proliferation. Thus, it is important to establish a specific marker, as well as clearly elucidate its etiology for diagnosis and proper treatment. We previously established immortalized cell lines from human ossifying fibromas of the jaw and found that they highly expressed the receptor for hyaluronan (HA)-mediated motility (RHAMM). In this study, we examined the expression of RHAMM mRNA in 65 fibro-osseous lesions, including ossifying fibroma, fibrous dysplasia and osseous dysplasia, as well as 5 normal jaws, using real-time RT-PCR and immunohistochemistry assays. RHAMM mRNA and protein expression were significantly elevated in the ossifying fibroma specimens. These results suggest that detection of upregulated RHAMM expression in an ossifying fibroma assists with differential diagnosis and has a key role in elucidation of its pathophysiology.

Ameloblastic carcinoma, secondary type, of the mandible: a case report

Ameloblastic carcinoma is a rare, odontogenic, malignant tumor that has features of ameloblastoma in addition to cytologic atypia with or without metastasis. It is classified as primary type; secondary type, intraosseous; and secondary type, peripheral according to the World Health Organization classification of 2005. Ameloblastic carcinoma, secondary type, is extremely rare, and few cases have been reported in the English-language literature. The authors report a case of ameloblastic carcinoma, secondary type, arising at the mandible in a 17-year-old Japanese boy.

nm23-H1 expression in salivary adenoid cystic carcinoma in relation to metastasis and survival

The expression of nm23-H1, product of putative metastasis suppressor gene, was evaluated immunohistochemically in 31 cases of adenoid cystic carcinoma (ACC) of salivary glands and correlated with their clinicopathologic features. All benign salivary gland tumors of various types, which were used as a non-metastatic control, showed obvious nm23-H1 expression. The immunoreactivity of tumor cells was stronger than that of normal salivary gland components, although the distribution patterns of positive cells considerably varied between tumor types. In ACC, 16 cases (52%) showed the reduction of nm23-H1 immunoreactivity either in positive cell frequency or staining intensity. These cases were referred to as negative cases. The incidence of negative cases was 67% (10/15) and 38% (6/16) of the cases with and without metastasis, respectively. Furthermore, metastatic tumors showed decreased immunoreactivity of this protein compared with their primary tumors. The prognosis of patients with a nm23 negative tumor was generally poorer than that with a positive tumor. These results may suggest that the reduction of nm23-H1 protein has an implication for metastasis of ACC.

Matrix metalloproteinase-13 (MMP-13) directly and indirectly promotes tumor angiogenesis

Matrix metalloproteinases (MMPs) are extracellular zinc-dependent endopeptidases involved in the degradation and remodeling of extracellular matrix in physiological and pathological processes. MMPs also have a role in cell proliferation, migration, differentiation, angiogenesis, and apoptosis. We previously identified cancer invasion-related factors by comparing the gene expression profiles between parent and the highly invasive clone of cancer cells. Matrix metalloproteinase-13 (MMP-13) was identified as a common up-regulated gene by cancer invasion-related factors. Although MMP-13 slightly promoted tumor invasion, we found that MMP-13 was involved in tumor angiogenesis. Conditioned medium from MMP-13-overexpressing cells promoted capillary formation of immortalized human umbilical vein endothelial cells. Furthermore, treatment with recombinant MMP-13 protein enhanced capillary tube formation both in vitro and in vivo. MMP-13-promoted capillary tube formation was mediated by activation of focal adhesion kinase and ERK. Interestingly, MMP-13 promoted the secretion of VEGF-A from fibroblasts and endothelial cells. By immunohistochemical analysis, we found a possible correlation between MMP-13 expression and the number of blood vessels in human cancer cases. In summary, these findings suggest that MMP-13 may directly and indirectly promote tumor angiogenesis.

Periostin directly and indirectly promotes tumor lymphangiogenesis of head and neck cancer

Background

Metastasis to regional lymph nodes via lymphatic vessels plays a key role in cancer progression. Tumor lymphangiogenesis is known to promote lymphatic metastasis, and vascular endothelial growth factor C (VEGF-C) is a critical activator of tumor lymphangiogenesis during the process of metastasis. We previously identified periostin as an invasion- and angiogenesis-promoting factor in head and neck squamous cell carcinoma (HNSCC). In this study, we discovered a novel role for periostin in tumor lymphangiogenesis.

Methods and Findings

Periostin overexpression upregulated VEGF-C mRNA expression in HNSCC cells. By using conditioned media from periostin-overexpressing HNSCC cells, we examined tube formation of lymphatic endothelial cells. Conditioned media from periostin-overexpressing cells promoted tube formation. To know the correlation between periostin and VEGF-C, we compared Periostin expression with VEGF-C expression in 54 HNSCC cases by immunohistochemistry. Periostin expression was correlated well with VEGF-C expression in HNSCC cases. Moreover, correlation between periostin and VEGF-C secretion was observed in serum from HNSCC patients. Interestingly, periostin itself promoted tube formation of lymphatic endothelial cells independently of VEGF-C. Periostin-promoted lymphangiogenesis was mediated by Src and Akt activity. Indeed possible correlation between periostin and lymphatic status in periostin-overexpressing xenograft tumors and HNSCC cases was observed.

Conclusions

Our findings suggest that periostin itself as well as periostin-induced upregulation of VEGF-C may promote lymphangiogenesis. We suggest that periostin may be a marker for prediction of malignant behaviors in HNSCC and a potential target for future therapeutic intervention to obstruct tumoral lymphatic invasion and lymphangiogenesis in HNSCC patients.

Direct observation of the hyperfine transition of ground-state positronium

We report the first direct measurement of the hyperfine transition of the ground state positronium. The hyperfine structure between ortho-positronium and para-positronium is about 203 GHz. We develop a new optical system to accumulate about 10 kW power using a gyrotron, a mode converter, and a Fabry-Pérot cavity. The hyperfine transition has been observed with a significance of 5.4 standard deviations. The transition probability is measured to be A = 3.1(-1.2)(+1.6) × 10(-8) s(-1) for the first time, which is in good agreement with the theoretical value of 3.37 × 10(-8) s(-1).

Myxolipoma in the tongue - a clinical case report and review of the literature

In this article, we present our experience with a case of myxolipoma of the tongue.

Lipoma is a mesenchymal benign tumor occurring with relatively high frequency. However, myxolipoma, one of the histological variant of lipoma characterized by mature adipose tissue and abundant mucoid substances, in the oral cavity is quite rare.

The patient was a 52-year-old man who noticed a painless mass on the left border of tongue about 2 years ago. The lesion was noted at a complete medical checkup, and the patient was admitted to our institution for detailed examination. The mass was a palpable, soft and elastic nodule, 15 mm in diameter, covered with normal mucosa in the left inferior aspect of the tongue. The border of the tumor was well-defined, and computed tomography (CT) revealed a fat density within the mass. On the basis of these finding, the tumor was clinically diagnosed as lipoma and was excised under general anesthesia. Histopathologically, the tumor was a well-defined lobulated mass surrounded by a thin fibrous capsule within the muscle of the tongue. The tumor was diagnosed as myxolipoma because it was consisted of solid proliferation of mature adipocytes replaced by abundant mucoid substances. The post operative course was uneventful, and there was no evidence of recurrence 4 years after surgery.