Decoding a gene expression program that accompanies the phenotype of sporadic and Basal Cell Nevus Syndrome-associated odontogenic keratocyst

BACKGROUND

Odontogenic keratocyst (OKC) is characterized by local aggressive behavior and a high recurrence rate, as well as the potential to develop in association with the Basal Cell Nevus Syndrome (BCNS). The aim of this study was to decode the gene expression program accompanying OKC phenotype.

METHODS

150-bp paired-end RNA-sequencing was applied on 6 sporadic and 6 BSCN-associated whole-tissue OKC samples in comparison to 6 dental follicles, coupled to bioinformatics and complemented by immunohistochemistry.

RESULTS

2,654 and 2,427 differentially expressed genes were captured to characterize the transcriptome of sporadic and BCNS-associated OKCs, respectively. Gene ontologies (GOs) related to "epidermis/skin development" and "keratinocyte/epidermal cell differentiation" were enriched among the upregulated genes (KRT10, NCCRP1, TP63, GRHL3, SOX21), while "extracellular matrix (ECM) organization" (ITGA5, LOXL2) and "odontogenesis" (MSX1, LHX8) GOs were overrepresented among the downregulated genes in OKC. Interestingly, upregulation of various embryonic stem cells (ESCs) markers (EPHA1, SCNN1A) and genes committed in cellular reprogramming (SOX2, KLF4, OVOL1, IRF6, TACSTD2, CDH1) was found in OKC. These findings were highly shared between sporadic and BCNS-associated OKCs. Immunohistochemistry verified SOX2, KLF4, OVOL1, IRF6, TACSTD2/TROP2, CDH1/E-cadherin, and p63 expression predominantly in the OKC suprabasal epithelial layers.

CONCLUSION

The OKC transcriptomic profile is characterized by a prominent epidermal and dental epithelial fate, a repressed dental mesenchyme fate combined with deregulated ECM organization, and enhanced stemness gene signatures. Thus, we propose a developed epidermis-like phenotype in the OKC suprabasal epithelial cells, established in parallel to a significant upregulation of marker genes related to ESCs and cellular reprogramming. This article is protected by copyright. All rights reserved.

Richter transformation in the oral and maxillofacial area: report of 2 cases and literature review

Richter transformation (RT) is a term used to refer to the development of an aggressive lymphoma, usually of diffuse large B-cell lymphoma type, in a patient with a history of chronic lymphocytic leukemia. It may present with heterogeneous manifestations, including the occurrence of tumors at extranodal sites. To date, only 6 cases of RT involving the oral and maxillofacial region have been reported. Here, we present 2 rare cases of lymphoma initially affecting the maxilla and the lower gingiva, respectively, of female patients with chronic lymphocytic leukemia and review the English language literature about RT manifesting in the oral and maxillofacial tissues.

Assessment of TLR4 and TLR9 signaling and correlation with human papillomavirus status and histopathologic parameters in oral tongue squamous cell carcinoma

OBJECTIVES

Toll-like receptors (TLRs) may promote or inhibit tumor progression. The aim of this study was to assess the expression of TLR4 and TLR9 and their downstream targets in oral tongue squamous cell carcinoma (OTSCC) in correlation with histopathologic parameters and human papillomavirus (HPV) status.

STUDY DESIGN

OTSCC (fully or superficially invasive and in situ) were studied. Immunohistochemical expression of TLR4, TLR9, nuclear factor-κΒ (NF-κΒ/p65), and interferon-β (IFN-β) was evaluated in tumor and inflammatory cells and in adjacent morphologically normal mucosa. HPV status was also determined.

RESULTS

TLR4 showed increased expression levels in tumor and infiltrating inflammatory cells compared with adjacent mucosa, especially in fully invasive cases; a negative correlation between TLR4 levels in inflammatory cells and tumor grade was observed. TLR9 was upregulated in tumor and infiltrating inflammatory cells compared with the adjacent mucosa; its expression in inflammatory cells was higher in well differentiated tumors. NF-κΒ and IFN-β were elevated in cancerous tissues, especially in fully invasive cases, and positively correlated with TLR4 and/or TLR9. HPV positivity (detected in 15.9% of the cases) demonstrated positive correlation with TLR9 and NF-κΒ levels.

CONCLUSIONS

TLR4 and TLR9 are upregulated in OTSCC and its microenvironment and, by affecting important downstream molecules, such as NF-κB and IFN-β, may play a role in oral cancer development and progression.

Oral ulceration with bone sequestration: Retrospective study of eight cases and literature review

OBJECTIVE

Oral ulceration with bone sequestration (OUBS) describes a site-specific intraoral ulcer that covers exposed, non-vital bone in patients lacking any etiological factor known to induce osteonecrosis. We aimed to conduct a retrospective study of eight new cases of OUBS and review the literature.

SUBJECTS AND METHODS

This is a retrospective study of OUBS cases, diagnosed and managed during 2007-2017. Inclusion criteria were the presence of oral ulcer with exposed non-vital bone at sites of bone prominence and the absence of any factor known to cause osteonecrosis. The English literature was reviewed on original OUBS cases.

RESULTS

Eight patients (5 males and 3 females, aged 27-75 years) were diagnosed with OUBS during years 2007-2017. Four cases involved the mandibular mylohyoid ridge, one a mandibular anterior exostosis and three the maxillary buccal/palatal exostoses. Exposed bone was removed under local anesthesia, resulting in complete healing in all cases. The literature review yielded 32 OUBS cases in the mandible.

CONCLUSION

Oral ulceration with bone sequestration is a distinct, probably under-reported rather than rare clinical entity that should be regarded the provisional diagnosis in case of an oral ulcer covering exposed, non-vital bone at sites of bone prominence in patients lacking any etiological factor known to induce osteonecrosis.

Alterations in the expression of DNA damage response-related molecules in potentially preneoplastic oral epithelial lesions

OBJECTIVES

The aim of this study was to evaluate the expression levels of DNA damage response (DDR) markers in potentially preneoplastic oral epithelial lesions (PPOELs).

STUDY DESIGN

Immunohistochemical expression of DDR markers (γΗ2 ΑΧ, pChk2, 53 BP1, p53, and phosphorylated at Ser 15 p53) was assessed in 41 oral leukoplakias, ranging from hyperplasia (H) to dysplasia (D) and in comparison with oral squamous cell carcinoma (OSCC) and normal mucosa (NM). Statistical and receiver operating characteristic curve analysis were performed.

RESULTS

γH2 AX immunoexpression demonstrated a gradual increase and upper layer extension from NM to H to higher D degrees to OSCC. pChk2 expression was minimal in NM, relatively low in PPOELs, with an increasing tendency from H to D, and higher in OSCC. 53 BP1 demonstrated higher levels in OSCC than in NM, whereas its expression in PPOELs was heterogeneous, gradually increasing according to D. p53 demonstrated progressively higher levels and upper layer extension from H to D to OSCC. Phosphorylated p53 was absent in NM and relatively low in PPOELs and OSCC.

CONCLUSIONS

DDR markers' expression is variable in PPOELs, showing a tendency to increase along with dysplasia. Activated DDR mechanisms may play an important protective role at early stages of oral carcinogenesis, but probably suffer progressive deregulation, eventually failing to suppress malignant transformation.

Spongiotic Gingival Hyperplasia Synchronously Involving Multiple Sites: Case Report and Review of the Literature

Localized juvenile spongiotic gingival hyperplasia (LJSGH) is a gingival lesion with unique clinicopathologic features that may involve synchronously multiple sites. We present a case with lesions clinically consistent with LJSGH in four jaw quadrants, confirmed by biopsy and review the English literature on multifocal LJSGH cases. A 19 year-old woman presented with circumscribed, erythematous overgrowths on the right and left maxillary and mandibular gingiva. With the provisional diagnosis of multifocal LJSGH, total excision of four maxillary lesions was performed. Clinical, microscopic and immunohistochemical examination with cytokeratin 19 confirmed the diagnosis of LJSGH in multiple sites. The excised lesions showed partial to complete recurrence after 4 months, while spontaneous regression of all but one lesion was observed after 15 months. Twenty cases with synchronous involvement of the gingiva of at least two teeth were previously reported. Their clinical features were comparable to that of solitary LJSGH. Only one case involved all four jaw quadrants. Spontaneous remission has not been documented before. The recognition of multiple lesions with clinicopathologic features diagnostic of LJSGH in the same adult patient argue against the designations "localized" and "juvenile". Recurrences are common, while remission might occur.

Recurrence in a patient with a 10-year history of sinonasal mucosal melanoma manifesting as facial swelling

Sinonasal mucosal melanoma is a rare tumor that develops slowly and may manifest with non specific signs and symptoms, causing significant delay in diagnosis. Local recurrence is common and usually occurs within the first two years after the initial treatment. Prognosis of recurrent lesions is poor and 5-year survival ranges between 10-47%. We report the clinical, radiographic, histopathological and immunohistochemical findings of a recurrent sinonasal mucosal melanoma which was diagnosed 10 years after the initial treatment, in a patient who presented with unilateral facial swelling and one-sided difficulty in breathing of two years duration. We discuss the causes of late diagnosis and review the negative predictive factors for recurrence and survival. As early diagnosis is of paramount importance for prognosis, we emphasize the signs and symptoms of patients with a history of sinonasal mucosal melanoma which should raise the suspicion for recurrence, in spite of a long time interval since diagnosis. Key words: Mucosal melanoma, nasal cavity, sinus, recurrence.

Ductal cells of minor salivary glands in Sjögren's syndrome express LINE-1 ORF2p and APOBEC3B

BACKGROUND

Type I interferon activation is a hallmark event in Sjögren's syndrome. L1 retroelements stimulate plasmacytoid dendritic cells, activating the type I interferons, and are regulated by various mechanisms, including the APOBEC3 deaminases. As L1s are potential trigger factors in autoimmunity, we aimed to investigate the immunohistochemical localization of L1 ORF2p and its inhibitor APOBEC3B protein in minor salivary glands of Sjögren's syndrome patients.

METHODS

Twenty minor salivary gland-tissue samples from 20 Sjögren's syndrome patients, classified according to Tarpley's histological criteria, and 10 controls were evaluated for L1 ORF2p and APOBEC3B expression via immunohistochemistry.

RESULTS

L1 ORF2p was expressed in 17/20 SS patients and all controls. APOBEC3B expression was observed in 15/20 Sjögren's syndrome patients, 5/5 chronic sialadenitis, and 3/5 normal minor salivary glands. Both antibodies stained the cytoplasm of the ductal epithelial cells. Negative staining was observed in the acinar cells. L1 ORF2p-positive immunostaining was significantly lower in Tarpley IV Sjögren's syndrome patients than controls (P = .039), and APOBEC3B-positive staining was significantly lower in Tarpley I compared to Tarpley II Sjögren's syndrome patients (P = .008) and controls (P = .035).

CONCLUSIONS

L1 ORF2p and APOBEC3B are expressed in the ductal epithelial cells of minor salivary glands that are among the key targets in Sjögren's syndrome. L1 ORF2p expression may promote the L1 ability to act as an intrinsic antigen in Sjögren's syndrome. The potential future use of L1 ORF2-reverse transcriptase inhibitors in autoimmunity supports further investigation of L1 epigenetic regulation by APOBEC3 enzymes.

Oral lymphoepithelial cyst: A clinicopathological study of 26 cases and review of the literature

Introduction

Τo describe the clinicopathological features of 26 oral lymphoepithelial cysts (LECs) and review the literature.

Material and Methods

Twenty-six cases of oral LECs diagnosed during a 37-year period were retrospectively collected. The patients’ gender and age, as well as the main clinical features of the cysts were retrieved from the requisition forms. The main microscopic features were recorded after reevaluation of all cases. Pubmed and Google Scholar electronic databases were searched with the key word “oral LEC”. Inclusion criteria were the microscopic confirmation of LEC diagnosis and the report at least two of three main clinical features (gender, age and cyst’s location).

Results

The 26 oral LECs represented 0.08% of 31,564 biopsies accessioned during the study period. They affected 25 patients, 14 females and 11 males with a mean age of 33.04±9.81 years. They appeared as smooth (92%) nodules, with soft (24%) or firm (76%) consistency and normal (28%), yellow to normal (20%), yellow (32%) or white (20%) hue, in the tongue (69.23%) or the floor of mouth (30.77%). They were covered by parakeratinized squamous (92.31%) or non-keratinized (7.69%) epithelium and contained desquamated epithelial cells, amorphous eosinophilic material and/or inflammatory cells (100%). The lymphoid tissue surrounded the cystic cavity partially (34.62%) or completely (65.38%), often in a follicular pattern with prominent germinal centers (53.85%). Literature review yielded 316 cases of oral LECs derived from 25 case reports, 3 case studies/retrospective studies with detailed information for each case and 7 studies with summarized data.

Conclusions

Oral LEC is a pathologic entity with discrete clinical presentation that is, however, commonly misdiagnosed in clinical practice as other, mostly benign, entities. Its pathogenesis remains obscure, as its clinicopathologic features are consistent with both theories suggested up to date.

Key words:Oral lymphoepithelial cyst; developmental cyst; non odontogenic cyst; lymphoid tissue; oral tonsil.

Ossifying Fibromyxoid Tumor of the Retromolar Trigone: A Case Report and Systematic Review of the Literature

Ossifying fibromyxoid tumor (OFMT) is a mesenchymal neoplasm of uncertain lineage and intermediate biologic behavior. Involvement of the head and neck area is infrequent (10% to 15%) and intraoral presentation is very rare. An OFMT developing in the retromolar trigone of a 13-year-old male is presented, along with a comprehensive review of oral OFMT cases. Among 12 oral OFMTs (including the present case), most patients were male (72.7%), with a mean age of 30.3 (13-67) years. The tumors generally appeared as painless masses of firm or hard consistency (mean diameter 27.7 mm), most commonly located in the soft tissues of the mandible (50%). Common microscopic features included ossification, lack of atypia or high mitotic activity, and immunohistochemical positivity for S100 (5/7), vimentin (6/6), GFAP (3/6), and SMA (2/6). Recurrence was reported only in one case. Further characterization of this rare entity is needed to increase our understanding of its distinct clinical and histopathologic features.

MALT Lymphoma of Minor Salivary Glands in a Sjögren's Syndrome Patient: a Case Report and Review of Literature

Background

Sjögren’s syndrome is a chronic systemic disease, characterized by lymphocytic infiltration and destruction mainly of the salivary and lacrimal glands, resulting in xerostomia and xeropthalmia. Sjögren’s syndrome patients have a 44-fold excess risk for the development of non-Hodgkin’s lymphoma particularly mucosa-associated lymphoid tissue (MALT) lymphoma, prevalently affecting the major salivary glands. In this report, a rare case of MALT lymphoma of minor salivary glands in a patient with Sjögren’s syndrome is described. A review of the published cases of MALT lymphoma located in the minor salivary glands of patients with Sjögren’s syndrome is provided.

Methods

In a 64-year-old female patient previously diagnosed with Sjögren’s syndrome, an asymptomatic soft tissue mass at the palate was noticed, exhibiting rapid enlargement within one month. With a main differential diagnosis of salivary gland neoplasm or lymphoproliferative lesion, a partial biopsy was performed accompanied by proper immunohistochemical analysis.

Results

A final diagnosis of MALT lymphoma was rendered and the patient was referred for further multidisciplinary evaluation. Gastric endoscopy and biopsy revealed a Helicobacter pylori-negative gastric MALT lymphoma, while spleen involvement and bone marrow infiltration were also identified. Patient was classified as having stage IV disseminated disease and a standard chemotherapy protocol was administered; the treatment was well tolerated and resulted in complete remission.

Conclusions

This case emphasizes the need for close monitoring of patients with Sjögren’s syndrome by oral medicine specialists, which, besides ensuring proper management of xerostomia and its sequelae, may also lead to early recognition of lymphoma development.

Non-healing tongue ulcer in a rheumatoid arthritis patient medicated with leflunomide. An adverse drug event?

Leflunomide is a member of the disease modifying anti-rheumatic drugs group used as a treatment modality in active rheumatoid and psoriatic arthritis. “Oral ulcers” are reported in 3-5% of leflunomide medicated rheumatoid arthritis patients with adverse events, but they are not described in detail in the literature. We present a case of an ulcer in the tongue of a rheumatoid arthritis patient managed with leflunomide and contemplate on its pathogenesis.

Key words:Leflunomide, oral ulcer, DHODH.

Transient lingual papillitis: A retrospective study of 11 cases and review of the literature

BACKGROUND

Transient lingual papillitis (TLP) is a common, under-diagnosed, inflammatory hyperplasia of one or multiple fungiform lingual that has an acute onset, and is painful and transient in nature.

MATERIAL AND METHODS

Eleven cases of TLP were diagnosed based on their clinical features. Information on demographics, clinical characteristics, symptoms, individual or family history of similar lesions, medical history, management and follow-up were extracted from the patients' records. The English literature was reviewed on TLP differential diagnosis, pathogenesis and management.

RESULTS

The study group included 8 females and 3 males (age: 10-53 years, mean age 31.7±12.88 years). Seven cases were classified as generalized form of TLP and 4 as localized form. Nine cases were symptomatic. Time to onset ranged from 1 to 14 days. A specific causative factor was not identified in any case and management was symptomatic.

CONCLUSIONS

Although TLP is not considered as a rare entity, available information is limited. Diagnosis is rendered clinically, while biopsy is required in cases with a differential diagnostic dilemma. TLP should be included in the differential diagnosis of acute, painful tongue nodules. Key words:Transient lingual papillitis, fungiform papillary glossitis, tongue, nodules.

ERK1/2, JNK and STAT3 activation and correlation with tumor differentiation in oral SCC

Signal transducer and activator of transcription 3 (STAT3) and mitogen activated protein kinases (MAPKs), including ERK and JNK, have been implicated in oral squamous cell carcinoma (OSCC) development and progression. Our purpose was to evaluate the levels of activated STAT3, ERK1/2 and JNK by immunohistochemistry in OSCC and to investigate possible correlations of these molecules with each other as well as with the degree of tumor differentiation. Immunohistochemical assessment of the phosphorylated levels of STAT3(tyrosine/ serine), ERK1/2 and JNK was performed in 60 OSCC, including well, moderately and poorly differentiated tumors. Semiquantitative scoring system was used, by calculating intensity of immunostaining, percentage of positive cells and combined scores. Statistics included Fisher's test, Student's T-Test and Kruskal-Wallis analysis, Spearman's correlation coefficient and multivariate logistic regression analyses. Immunohistochemical levels of both pSTAT3(tyr) and pERK1/2 showed statistically significant differences between well and poorly differentiated tumors with the latter receiving higher mean percentage, intensity and total scores. On the other hand, pJNK showed statistically significantly higher intensity levels in moderately compared to poorly differentiated tumors. pSTAT3(ser) immunoexpression did not appear to correlate with tumor differentiation. Between different molecules, more pronounced, pERK1/2 levels exhibited statistically significant positive correlation with pSTAT3(ser), pSTAT3(tyr) and pJNK expression. ERK1/2 and STAT3 activation (as assessed by tyrosine but not serine phosphorylation) could contribute to a less differentiated phenotype in OSCC, while JNK activation may have an opposite, although possibly less pronounced, effect. Positive correlations between MAPK and STAT3 levels may indicate a direct crosstalk and/or regulation by common upstream pathways.

Is dental implantation indicated in patients with oral mucosal diseases

Background/Aim: Dental implants are a reliable treatment choice for rehabilitation of healthy patients as well as subjects with several systemic conditions. Patients with oral mucosal diseases often exhibit oral mucosal fragility and dryness, erosions, blisters, ulcers or microstomia that complicate the use of removable dentures and emphasize the need for dental implants. The aim of the current study is to review the pertinent literature regarding the dental implantation prospects for patients with oral mucosal diseases. Material and Method: The English literature was searched through PubMed and Google Scholar electronic databases with key words: dental implants, oral mucosal diseases, oral lichen planus (OLP), epidermolysis bullosa (EB), Sjögren’s syndrome (SS), cicatricial pemphigoid, bullous pemphigoid, pemphigus vulgaris, scleroderma/systemic sclerosis, lupus erythematosus, leukoplakia, oral potentially malignant disorders, oral premalignant lesions, oral cancer and oral squamous cell carcinoma (SCC). Results: Literature review revealed dental implantation in patients with OLP (14 articles), EB (11 articles), pemphigus vulgaris (1 article), SS (14 articles), systemic sclerosis (11 articles), systemic lupus erythematosus (3 articles) and oral SCC development associated with leukoplakia (5 articles). No articles regarding dental implants in patients with pemphigoid or leukoplakia without SCC development were identified. Most articles were case-reports, while only a few retrospective, prospective or observational studies were identified. Conclusions: Dental implants represent an acceptable treatment option with a high success rate in patients with chronic mucocutaneous and autoimmune diseases with oral manifestations, such as OLP, SS, EB and systemic sclerosis. Patients with oral possibly malignant disorders should be closely monitored to rule out the development of periimplant malignancy. Further studies with long follow-up, clinical and radiographic dental data are required to predict with accuracy the outcome of dental implants in patients with oral mucosal diseases.

Evidence for APOBEC3B mRNA and protein expression in oral squamous cell carcinomas

It has been demonstrated that APOBEC3B possesses cytidine deaminase activity, which is likely to result in C-to-T signature mutations. Increased expression of the APOBEC3B gene has been shown to correlate with higher incidence of such mutations in various cancer types, such as breast, bladder, lung, and head and neck carcinomas. In the current study, we used in silico methods, immunohistochemistry and qRT-PCR to detect the presence of APOBEC3B signature mutations and examine the levels and patterns of APOBEC3B expression in oral squamous cell carcinomas (OSCCs). Using the Cancer Genome Atlas (TCGA) database, we have found a high incidence of C-to-T transitions in head and neck squamous cell carcinomas (HNSCCs), of which OSCCs constitute the largest subgroup. Additionally, we compared APOBEC3B expression, at both mRNA and protein level, between OSCCs and non-cancerous samples. APOBEC3B was detected in both groups, but nuclear localization was consistent only in normal oral cells. APOBEC3B mRNA levels were clearly higher in OSCCs than in controls. These results suggest that while in normal oral cells APOBEC3B has an important nuclear function to fulfill, this activity may be hindered in a subgroup of tumor cells, due to the more prominent localization of the enzyme in the cytoplasm.

Langerhans cell histiocytosis mimicking aggressive periodontitis: Challenges in diagnosis and management

OBJECTIVE

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by clonal proliferation of Langerhans cells that affects various organs. Oral involvement may simulate periodontal disease and cause significant diagnostic and management difficulties. Here, we present an interesting LCH case with severe periodontal destruction in a young woman in order to facilitate early recognition of this aggressive disease and successful participation of the general practitioner in the management of such patients.

CASE PRESENTATION

A 21-year-old woman was referred for evaluation of recurrent episodes of dull pain in the gingiva for the last 9 months, which had not been successfully managed by her general practitioner. Clinical and radiographic examination showed extensive alveolar bone loss. Histopathologic examination revealed diffuse aggregates of Langerhans cells, while a complete work-up did not demonstrate evidence of systemic involvement. A diagnosis of LCH limited to the oral cavity was established. The patient received systemic chemotherapy in combination with appropriate dental care including gingival debridement and tooth immobilization. Following chemotherapy completion, comparative clinical, radiographic, and microscopic evaluation showed complete remission. During an 18-month follow-up period, frequent oral examinations and appropriate dental interventions confirmed the lack of LCH recurrence and guaranteed the stabilization of periodontal tissues.

CONCLUSIONS

Oral soft and hard tissue involvement may be the only manifestation of LCH. The present case exemplifies the importance of close collaboration between general dentistry and its disciplines (periodontology, restorative dentistry, oral medicine, oral and maxillofacial pathology, and oral radiology), and hematology-oncology for diagnosis, management, treatment monitoring, and decision-making.

Immunohistochemical evaluation of the mTOR pathway in intra-oral minor salivary gland neoplasms

OBJECTIVES

The aim of this study was to investigate the expression of upstream and downstream molecules of the oncogenic mTOR signaling pathway in intra-oral minor salivary gland tumors (SGTs).

MATERIALS AND METHODS

Tissue samples consisted of 39 malignant and 13 benign minor SGTs, and 8 controls of normal minor salivary glands (NMSG). An immunohistochemical analysis for phosphorylated Akt, 4EBP1 and S6 (total and phosphorylated), and eIF4E was performed.

RESULTS

Expression of pAkt and 4EBP1 was observed in all SGTs and in most NMSG. p4EBP1 was detected in almost all SGT cases, NMSG being negative. S6 immunoreactivity was observed in 37.5% of NMSG, 92.3% of benign and 100% of malignant SGTs, while pS6 expression was observed in 77% of benign and 95% of malignant SGTs, but not in NMSG. Finally, eIF4E was expressed in 12.5% of NMSG, 69.2% of benign, and 76.9% of malignant tumors. All molecules studied had statistically significantly lower expression in NMSG compared with SGTs. Moreover, malignant neoplasms received higher scores compared with benign tumors for all molecules with the exception of eIF4E.

CONCLUSION

The mTOR signaling pathway is activated in SGTs, especially in malignancies. Therefore, the possible therapeutic role of targeting the mTOR pathway by rapamycin analogs in SGTs needs further investigation.

JNK1/2 expression and modulation of STAT3 signaling in oral cancer

Mitogen-activated protein kinases (MAPKs) are a family of protein kinases that link extracellular stimuli with intracellular responses and participate in numerous cellular processes such as growth, proliferation, differentiation, inflammation and apoptosis. Persistent activation of signal transducer and activator of transcription 3 (STAT3), which is accompanied by increases in STAT3 tyrosine phosphorylation, is associated with cell proliferation, differentiation and apoptosis in oral squamous cell carcinoma (OSCC). The role and significance of the activation of MAPKs, particularly of c-Jun N-terminal kinase (JNK), on STAT3 signaling in OSCC have not been thoroughly investigated. The present study examines the effects of JNK1/2 modulation on STAT3 signaling and cellular activities in OSCC cells. The expression levels of STAT3 [total, tyrosine phosphorylated (p-Tyr) and serine phosphorylated (p-Ser)], JNK, c-Jun and cyclin D1 were assessed in the OSCC cell lines SCC25 and SCC9. Inhibition of JNK1/2 was achieved by pharmacological agents (SP600125) and by small interfering RNA (siRNA) silencing, while JNK1/2 was induced by active MAPK kinase 7. Cell proliferation and viability rates were also evaluated. Inhibition of JNK1/2 with either SP600125 treatment or specific siRNA silencing resulted in decreased levels of p-Ser STAT3 and increased levels of p-Tyr STAT3 and cyclin D1 in both cell lines. Furthermore, JNK1/2 inhibition resulted in a dose-dependent increase in cell growth and viability in both cell lines. Opposite results were observed with JNK1/2 induction in both cell lines. The present results are supportive of a potential tumor suppressive role of JNK1/2 signaling in OSCC, which may be mediated through negative crosstalk with the oncogenic STAT3 signaling pathway. The possible therapeutic implications of JNK1/2 inhibition for patients with OSCC require to be investigated.

Peripheral Tumor with Osteodentin and Cementum-like Material in an Infant: Odontogenic Hamartoma or Odontoma?

The purpose of this report is to describe a peripheral tumor on the mandibular alveolar ridge of a seven-month-old Caucasian boy, consisting of ectomesencymal odontogenic tissues, in particular osteodentin and cementum-like material, in a cellular or loose vascular connective tissue stroma. This case may be considered either a peripheral odontogenic hamartoma or a peripheral odontoma.

In Vivo Antineoplastic Effects of the NSAID Sulindac in an Oral Carcinogenesis Model

The antineoplastic properties of the NSAID sulindac have long been studied. The purpose of this study was to explore sulindac's in vivo effects on oral squamous cell carcinoma (SCC) oncogenesis using the hamster cheek pouch oral carcinogenesis model (HOCM). Thirty Syrian golden hamsters were divided into three experimental and two control groups (n = 6 each). The animals' right buccal pouches were treated with carcinogen for 9 weeks in one experimental and one control group and for 14 weeks in all other three groups. The animals of two experimental groups received sulindac from the 1st week and those of the third experimental group from the 10th week. After the end of carcinogenesis, treated buccal pouches were removed and examined. In animals treated with carcinogen for 14 weeks, development of oral SCC and tumor volume were significantly lower in animals that received sulindac from the first week of the experiment. Oral SCC developing in animals that received sulindac were more frequently well differentiated compared with the control group. In animals treated with carcinogen for 9 weeks, the animals that received sulindac developed lower grade of epithelial dysplasia. Proliferation index Ki-67 and positivity for the antiapoptotic molecule survivin were lower in the animals that received sulindac. Treatment with sulindac appears to delays the progression of oral premalignant lesions to oral SCC in the HOCM, also resulting in smaller and better differentiated tumors. These in vivo antineoplastic effects may be related to sulindac's ability to decrease cell proliferation and to prevent survivin expression.

The role of mTOR signaling pathway in premalignant and malignant cervical lesions

PURPOSE OF THE STUDY

Aberrant activation of the Akt/mTOR/pS6 signaling pathway has been identified in various types of cancer and is under investigation in cervical cancer. The purpose of this study was to assess the expression of the phosphorylated/activated forms of Akt (upstream molecule), 4E-BP1 and pS6 (downstream molecules) in biopsy samples of cervical low grade squamous intraepithelial lesions (LSIL), high grade squamous intraepithelial lesions (HSIL), and squamous cell carcinoma (Ca) compared to normal cervical epithelium.

MATERIAL AND METHODS

The study included 38 cases diagnosed as LSIL, 31 cases as HSIL, 29 cases as Ca, and eight control cases from normal cervix. Immunohistochemistry was used to assess the expression of pAkt, p4E-BP1 and pS6.

RESULTS

Statistical analysis revealed significant differences between HSIL and Ca groups compared to controls regarding intensity, positivity, and total scores for all three molecules (p < 0.001). A trend for higher expression with increasing grade of dysplasia was demonstrated.

CONCLUSION

These results strongly support the view that the mTOR signaling pathway is involved in cervical carcinogenesis.

mTOR inhibitor-associated stomatitis (mIAS) in three patients with cancer treated with everolimus

Mammalian targets of rapamycin inhibitors (mTOR inhibitors, mTORI) are indicated for the management of several cancer types, including hormone receptor--positive or HER2-negative breast cancer, advanced renal cell carcinoma, advanced neuroendocrine tumors of pancreatic origin, and tuberous sclerosis complex-related tumors. Among the most common adverse events of mTORI medication are discrete, large, solitary or multiple, superficial ulcers, almost exclusively situated on nonkeratinized oral mucosa, described as mTORI-associated stomatitis (mIAS). We describe the clinical presentation, course, and management of mIAS in three patients receiving the mTORI everolimus (Afinitor, Novartis, East Hanover, NJ). In two patients, mIAS manifested 9 and 30 days after first using everolimus, respectively, whereas in the third patient, it recurred 3 months after re-introduction of everolimus. Oral rinses with a "magic mouthwash" solution (dexamethasone oral drops solution 2 mg/mL × 10 mL, lidocaine gel 2% × 30 g, doxycycline suspension 50 mg/5 mL × 60 mL, and sucralfate oral suspension 1000 mg/5 mL × 150 mL, dissolved in sodium chloride 0.9% × 2000 mL) four times daily proved helpful in alleviating the symptoms, and the ulcers healed in 4 to 15 days. No side effects were recorded, and dose reduction or discontinuation of everolimus was not necessitated in two cases.

Periapical lesions are not always a sequelae of pulpal necrosis: a retrospective study of 1521 biopsies

AIM

To record the incidence of lesions that were not the sequelae of pulpal necrosis (non-SPN) amongst 1521 biopsies of periapical lesions submitted with a clinical diagnosis of a sequelae of pulpal necrosis (SPN).

METHODOLOGY

A retrospective study of 1521 biopsy request forms of specimens submitted for histopathological examination with a clinical diagnosis 'periapical inflammation', 'periapical abscess', 'periapical granuloma' or 'periapical cyst' during an arbitrarily selected 14-year period was undertaken. Gender and age of the patient, site and maximum diameter of the lesion, symptoms, inclusion of the final diagnosis in the differential diagnosis and specialty of the clinician submitting the biopsy material were recorded in each case. The final diagnosis for each case was extracted from the pathology report, and two groups were formed, SPN and non-SPN lesions. Differences between the respective features of SPN and non-SPN cases were analysed with Yate's chi-square test and t-test (significance level P < 0.05) RESULTS: In 52 of the 1521 cases examined (3.42%), the histological diagnosis was not consistent with a SPN. In most non-SPN cases, the histopathological diagnosis was not included in the differential diagnosis. The keratocystic odontogenic tumour [odontogenic keratocyst (OKC)] was the most frequent non-SPN lesion (34.62%). Other, yet less frequent, non-SPN lesions included glandular odontogenic cysts, lateral periodontal cysts, central ossifying fibromas as well as malignancies (metastatic carcinomas and Langerhans cell histiocytosis).

CONCLUSIONS

Non-SPN lesions appeared in the periapical region mimicking a SPN, although rarely. Most of them were developmental cysts, in particular OKCs, but odontogenic tumours, such as ameloblastoma, or malignant lesions were also diagnosed. Histological examination of tissue harvested from periapical lesions should be performed, in particular when those lesions are large.

Endoplasmic Reticulum Stress-Associated Chaperones, Bip/GRP78 and Calnexin are Overexpressed in Keratocystic Odontogenic Tumours

Objectives

Odontogenic keratocysts (OKCs) are developmental cysts that have been reclassified according World Health Organization (WHO), to keratocystic odontogenic tumours (KCOTs), a term that better reflects their neoplastic nature. The aim of present study is to evaluate the induction of stress of the endoplasmic reticulum and execution of the resulting unfolded protein response in keratinocystic odontogenic tumours.

Material and Methods

We analyzed by immunohistochemistry the expression of the chaperones BiP/GRP78 and calnexin in 24 cases of KCOTs. As controls, we have used 9 cases of periapical or radicular cysts (PACs) and 5 cases of Fibromas (FBs). The PACs and the FBs were included in the analysis, as PACs are the most common type of inflammatory odontogenic cysts of and FBs, as lesions of the connective tissue with unaffected epithelium.

Results

Analysis revealed a strong association between both BiP/GRP78 and calnexin expression and KCOTs: 18 out of 24 (75%) KCOTs expressed BiP/GRP78 as opposed to 1 out of 9 (13%) PACs, and none of 5 FBs evaluated (P < 0.001, x²-test). Calnexin was expressed in 11 out of 24 KCOTs (46%) but only one out of 9 (13%) PACs, and none of the 5 FBs analyzed (P < 0.001, x²-test).

Conclusions

Study results imply that induction of endoplasmic reticulum stress maybe of diagnostic value in keratocystic odontogenic tumours characterization. In addition to recent findings suggesting that endoplasmic reticulum stress plays a causative role in keratinization of epithelia, pharmacological interference with the execution of the unfolded protein response should be considered for the management of keratocystic odontogenic tumours.

Junctional spitz tumor (nevus) of the upper lip

Spitz tumor (nevus) is a rare, melanocytic lesion that primarily affects children and adolescents. The lesion may share many clinical and histological similarities with malignant melanoma and careful microscopic examination is required to render the proper diagnosis. Complete excision with close follow-up is considered the appropriate treatment. Despite the common presentation of Spitz nevi on the facial skin, lip involvement has only rarely been described in the English language literature. In the present study, a case of Spitz tumor located on the vermilion border of the upper lip in a 16-year old female patient is reported.

Assessment of angiogenic markers and female sex hormone receptors in pregnancy tumor of the gingiva

PURPOSE

Oral pregnancy tumors (OPTs) arise on the inflamed gingiva of women after the first trimester of pregnancy. The expression of angiogenic markers and female hormone receptors was assessed.

MATERIALS AND METHODS

Immunohistochemistry was used to analyze the expression of estrogen and progesterone receptors and the expression of angiogenic factors, such as vascular endothelial growth factor (VEGF) and its receptor, fibroblast growth factor (FGF), and hypoxia inducible factors 1α and 3α (HIF1α and HIF3α). Experimental groups included 9 OPTs, 10 oral pyogenic granulomas from nonpregnant women of the same age, and 9 oral pyogenic granulomas from postmenopausal women.

RESULTS

VEGF expression in stromal histiocytes and endothelial cells of small vessels was positively correlated in the OPT group (P < .05 by χ(2) test). VEGF receptor also was overexpressed in stromal histiocytes and endothelial cells of OPTs compared with oral pyogenic granulomas from nonpregnant and postmenopausal women (P < .005 by χ(2) test). No correlation was detected among estrogen and progesterone receptors, FGF and HIF1α and HIF3α (ER and PgR respectively) in the 3 experimental groups.

CONCLUSIONS

VEGF-associated angiogenesis is most likely involved in the pathogenesis of the lesion. These results imply that local inhibition of VEGF activity could be an adjuvant therapeutic approach for OPTs to control hemorrhage, which can be massive at the surgical excision of such lesions during pregnancy.

TGF-β1, Smad-2/-3, Smad-1/-5/-8, and Smad-4 signaling factors are expressed in ameloblastomas, adenomatoid odontogenic tumors, and calcifying cystic odontogenic tumors: an immunohistochemical study

OBJECTIVES

The TGF-β/Smad signaling pathway regulates diverse cellular functions, including tooth development, and is involved in numerous pathological processes such as tumorigenesis. The aim of this study was to investigate the immunoexpression of the TGF-β/Smad signaling pathway members in ameloblastoma (AM), calcifying cystic odontogenic tumor (CCOT), and adenomatoid odontogenic tumor (AOT).

MATERIALS AND METHODS

This retrospective cross-sectional study included 65 tissue specimens: 34 AMs, 13 CCOTs, and 18 AOTs. Serial sections were immunohistochemically stained with TGF-β1, Smad-4, Smad-1/-5/-8, and Smad-2/-3 antibodies, and a semiquantitative measurement of the positive cells was carried out by two oral pathologists using a 0-3 scale (0: no immunoreactivity, 1: <20% positive cells, 2: 20-50% positive cells, 3: >50% positive cells).

RESULTS

All biomarkers studied were found significantly decreased in AM compared to CCOT and AOT. AOT and CCOT expressed Smad-1/-5/-8 more strongly compared to AM (OR = 11.66, P < 0.001 and OR = 5.34, P = 0.013, respectively), and Smad-2/-3 immunostaining was found significantly increased in CCOT (OR = 10.42, P = 0.001) and AOT (OR = 5.16, P < 0.004) compared to AM. Similarly, Smad-4 was expressed more strongly in AOT and CCOT compared to AM (P = 0.001), while AOT demonstrated a fivefold higher chance to express TGF-β1 compared to AM (P = 0.011).

CONCLUSION

TGF-β/Smad signaling pathway is activated in AM, AOT, and CCOT. The statistically significant reduced TGF-β1/Smad immunoexpression in AM compared to AOT/CCOT could be associated with the more aggressive biological behavior of AM including increased cell proliferation and reduced apoptosis and differentiation. Thus, the biomarkers TGF-β, Smad-4, Smad-1/-5/-8, and Smad-2/-3 could serve as supplementary diagnostic indices between odontogenic tumors of high and low neoplastic dynamics.

Prosthodontic treatment of a class IV ACP PDI patient, with Langerhans cell histiocytosis (LCH)

Langerhans cell histiocytosis (LCH) is a disease of unknown etiology with a frustrating and unpredictable course. Surviving adult patients suffering from the multisystem type of the disease present with problems in most organs. This article presents the oral rehabilitation of a 28-year-old patient, with multisystem sequelae that included the oral cavity, classifying him as a Class IV American College of Prosthodontists Prosthodontic Diagnostic Index patient. A 5-year course of treatment is analyzed, starting from merely replacing missing teeth with a removable partial denture. The second stage of prosthetic rehabilitation included replacement of the removable prosthesis with fixed partial dentures. The final and most important aspect of treatment was the 2-year follow-up, when the patient presented with no problems or adverse effects. The purpose of this presentation is to offer an insight to prosthodontic treatment possibilities for patients suffering from multisystem LCH and to show the value of a "team approach" to achieving a positive outcome.

p21/waf1 and smooth-muscle actin α expression in stromal fibroblasts of oral cancers

Background: Concerted alterations between stromal fibroblasts and neoplastic cells underline the carcinogenic process. Activation of alpha-smooth muscle actin (SMA) expression, a cytoskeleton protein normally expressed only in myoepithelial cells, is considered a landmark for the activation of stromal fibroblasts with little however being known regarding the mechanism governing the expression of SMA in the stroma.

Methods: We have evaluated by immunohistochemistry the expression of SMA in the stroma of oral malignant and pre-malignant lesions, in association with the expression of p53 and p21 tumor suppressors that were shown previously to be deregulated and/or mutated in stromal fibroblasts of various cancers. The effects of p21 knockdown in SMA expression and cell migration and the mRNA levels of endogenous p21 in fibroblasts co-cultured with cancer cells were also assessed.

Results: We found that both p21 and SMA expression was elevated in the stroma, but not the epithelium, of malignant as compared to pre-malignant lesions. We also noted that the expression of both was positively correlated, implying that SMA expression may be regulated by p21. Consistently with this notion we found that siRNA-mediated p21 suppression resulted in the reduction of SMA levels and also inhibited cell migration.

Conclusion: Our results show that p21 deregulation is associated with the activation of stromal fibroblasts of oral cancers by a mechanism that involves the stimulation of SMA expression.

Oral manifestations of T-cell large granular lymphocytic leukemia: a case report

Background

T-cell large granular lymphocytic (T-LGL) leukemia is a rare, chronic, often indolent lymphoproliferative disorder of mature T cells (CD3+). Severe neutropenia and other cytopenias are common features in patients with T-LGL leukemia and may cause infections, thus representing a major cause of morbidity in this disease. Immunosuppressive therapy with low-dose regimes of methotrexate, cyclophosphamide, corticosteroids or cyclosporine A is the treatment of choice. Amongst the variety of T-LGL leukemia complications, oral manifestations such as ulcers have been rarely reported. The purpose of this paper is to report a case of T-cell large granular lymphocyte leukemia with oral manifestations and to discuss their pathogenesis and management.

Methods

In the present case, a 65 year old female with a two-month history of diagnosed T-LGL leukemia presented with oral lesions, including ulcerations on the ventral tongue and soft palate as well as swollen, erythematous and ulcerated gingiva. The patient was under treatment with methotrexate, granulocyte colony-stimulating factor (G-CSF) and erythropoietin.

Results

Considering patients' medical history and clinical appearance of the lesions, a clinical diagnosis of a neutropenic ulcer of the tongue was established. The oral lesions resolved after treatment with antibiotics, topical steroids and antiseptics combined with improvement of the hematological condition. The pertinent literature related to T-LGL leukemia ethiopathology, diagnostics and treatment was discussed.

Conclusions

Although rare, T-cell large granular lymphocytic leukemia should be included in the list of lymphoproliferative disorders, which may present with oral manifestations as a result of the disease and its treatment complications.

Granular cell ameloblastoma: an unusual histological subtype report and review of literature

Background

Granular cell ameloblastoma is a rare histological subtype of ameloblastoma accounting for less than 5% of the total. The characteristic microscopic features of granular cells are attributed to the increased presence of lysosomes in the cytoplasm of the tumour cells.

Methods

A case of bone expansion in the mandible of 65 year old patient was examined on the basis of the clinical examination, radiographic imaging and microscopic features. A complete surgical removal was performed.

Results

The radiographic imaging characteristics were consistent with a locally aggressive jaw lesion. Histological examination of the tumour revealed typical features of granular cell ameloblastoma. The specimen margins were free of tumour and the postoperative course was uneventful. No evidence of recurrence was noticed during a 1.5 years follow-up period.

Conclusions

The rarity of the granular cell ameloblastoma subtype and the possibility of confusion with other odontogenic and non-odontogenic lesions with a granular cell component require an understanding of the salient features of this locally aggressive neoplasm. A literature review is provided focusing on emerging molecular parameters in the pathogenesis of these tumours and the differential diagnosis of oral lesions featuring granular cells.