Malignant transformation of oral leukoplakia: a follow-up study.

OBJECTIVE: The main objective of the study was to identify the determinants that contribute to the malignant transformation of oral leukoplakia in a group of patients managed in secondary care. A secondary objective was to compare two dysplasia grading systems to determine their utility in assessing the prognosis. MATERIAL AND METHODS: The cohort consisted of 93 patients diagnosed during the period 2009-2013. The variables recorded and analysed included age and sex, clinical presentation (colour) and severity of oral epithelial dysplasia (OED) scored by the WHO (2005) and the binary grading systems. The planned management included excision of high-grade dysplasia and observation of low-grade dysplasia lesions based on the WHO grading system. Patient factors were transcribed from the pathology records and updated using a questionnaire sent out to the whole group of patients. Data were analysed using χ2 test and Kaplan-Meier analysis (P < 0.05). RESULTS: Complete follow-up data were available for 93 patients. Malignant transformation occurred in 7 patients (7.5%) during a mean follow-up period of 30 months. Among the surgically excised group (n = 51), a recurrence of oral leukoplakia was noted in 16 patients (31%). WHO OED grading (P = 0.02) and the presence of red areas (P = 0.012) were useful in predicting malignant transformation with severe epithelial dysplastic lesions and red and white mixed lesions showing higher rates. CONCLUSION: Leukoplakias (7.5%) transformed over a mean follow-up period of 30 months. Dysplasia grading and the clinical appearance by colour (mixed white and red) were significant predictors of malignant transformation CLINICAL SIGNIFICANCE: Patients with erythroleukoplakia and those diagnosed with moderate or severe epithelial dysplasia require more intensive interventions as such lesions have a higher risk of developing a malignancy.

Descriptive study of 896 Oral squamous cell carcinomas from the only University based Oral Pathology Diagnostic Service in Sri Lanka.

BACKGROUND: The main objective of this study was to describe selected clinico-pathological characteristics of Oral Squamous Cell Carcinoma (OSCC) in Sri-Lanka. MATERIALS & METHODS: The study sample comprised of eight hundred and ninety six biopsies diagnosed as OSCC. The clinical and histopathological features were analyzed using the Chi-square test. RESULTS: Of the 896 biopsies, 801 were primary OSCCs, while 95 were recurrent OSCCs. Majority of the patients (78 %) were in the 5(th) to 7(th) decades of life and showed a male predilection. The buccal mucosa was the commonest site of primary OSCC comprising of 43 % of the sample. Of the primary OSCCs, with known TNM stage, 86 % were in stage 3&4 and majority (59 %) of stage 4 tumours showed tumour at one or more excision margins. Of the recurrent OSCC, 46 % developed their recurrences within one year of the excision of the primary tumour. CONCLUSION: In Sri-Lanka, OSCC is a major problem. Only half the patients had completely excised tumours (with clearance of >5 mm at all excision margins) at operation, and recurrences appeared early. This data should be considered in the future management policy of OSCC in Sri-Lanka.

A literature review on oral basaloid squamous cell carcinomas, with special emphasis on etiology.

In the recent years, basaloid squamous cell carcinomas (BSCCs) have gained attention because of (1) observation of a relative increase in the number of tumors arising particularly in head and neck sites, (2) identification of human papillomavirus (HPV) in BSCCs arising predominantly in the oropharynx, and (3) controversies that exist regarding the biological aggressiveness of the tumor. The objective of the present review was to address the issues mentioned above by focusing primarily on oral BSCCs, using literature that has been published in the English language up to 2013. According to the literature review, oral BSCCs were found to be relatively more common in elderly patients with a mean age of 64 years. A male predominance with a male/female ratio of 3:1 was observed. The predominant site was the tongue, with almost half of the reported cases occurring at this site, followed by the floor of the mouth and palate. With reference to habit history, majority were found to be tobacco and alcohol users. However, only 3 studies revealed data on HPV status of purely oral BSCC, and according to the results of these studies, of the 17 tumors tested, 4 had harbored high-risk HPV. Furthermore, most oral BSCCs were in an advanced clinical stage, namely, stage III or IV with T3 or T4 lesions and cervical lymph node metastasis at initial presentation, whereas 41% of patients had presented with local recurrences and 45% had died of the disease. In conclusion, although, the present literature review found enough evidence to consider tobacco and alcohol as risk factors for the development of oral BSCC, steps should be taken to fill the gap in our knowledge that exist with reference to contribution of oncoviruses, particularly HPV in the etiology of oral BSCC.

A Preliminary Study on Early Detection of Oral Cancer with Opportunistic Screening: Insights from Dental Surgeons in Sri Lanka.

In Sri Lanka, opportunistic screening is encouraged as a cost-effective tool to bring down the prevalence of oral cancer, which is the most common cancer among males. The objectives of the study were to determine the practices, attitudes, and level of competency of dental surgeons regarding the early detection of oral cancer and oral potentially malignant disorders (OPMDs) through opportunistic screening. A prospective study was conducted online via a Google form using a pretested, self-administered questionnaire of 22 close-ended questions and 3 open-ended questions. Out of the 137 dental surgeons who responded, 88% (121/137) of the participants believed that screening high-risk target groups would be more effective in the early detection of oral cancer rather than opportunistic screening. Only 64% (88/137) of the participants frequently check for oral cancer and OPMDs when patients visit for dental treatment. Participants recalled an average of 34 patients (4628/137) with clinically suspicious lesions being diagnosed during examination at general dental practice during the past year, and 98% (134/137) of the participants believed that they should receive additional training in order to identify and diagnose clinically suspicious oral OPMDs and oral cancer. Opportunistic screening in general dental practice as an oral-cancer prevention strategy is appreciable, but due emphasis should be given to other prevention strategies such as population screening and screening high-risk target groups. The level of confidence of general dental practitioners in the early detection of oral cancer has to be raised in order to achieve higher standards in oral cancer prevention through opportunistic screening.

Regenerative Potential of Mesenchymal Stem Cell-Derived Extracellular Vesicles.

Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into diverse cell lineages. MSC based therapy has become a widely experimented treatment strategy in regenerative medicine with promising outcomes. Recent reports suggest that much of the therapeutic effects of MSCs are mediated by their secretome that is expressed through extracellular vesicles (EVs). EVs are lipid bilayer bound components that carry cellular proteins, mRNA, lncRNAs, and other molecules in order to mediate intercellular communication and signaling. In fact, MSC-derived EVs have been observed to implement the same therapeutic effects as MSCs with minimal adverse effects and could be used as an alternative treatment method to MSC-based therapy. The regenerative activity of MSC-EVs has been observed in relation to multiple cell/tissue lineages using various animal models. However, further research and clinical trials are essential for the advancement of this novel treatment strategy. This review provides an insight into the available literature on applications of MSC-EVs in relation to angiogenesis, neurogenesis, hepatic and kidney regeneration, and wound healing.

Clinical and demographic characteristics of adenomatoid odontogenic tumors: analysis of 116 new cases from a single center.

INTRODUCTION: The adenomatoid odontogenic tumor is a relatively uncommon odontogenic neoplasm representing about 4.7% of all odontogenic tumors. OBJECTIVE: The aim of this study was to determine the demographic and clinical profile of the adenomatoid odontogenic tumors in a Sri Lankan population. METHODS: Data gathered from the cases received for a period of 38 years from the Department of Oral Pathology, Faculty of Dental Sciences, University of Peradeniya. Request forms, biopsy reports and electronic data base of the department were used to obtain relevant information. Demographic data including age, gender and location of the tumor were included in the analysis. RESULTS: Out of 116 cases of adenomatoid odontogenic tumor, the mean age was 21.02 ±â€¯11.24. It occurs more fre quently in the second decade of life, more prevalent in females, most often associated with the maxilla, predominantly affecting anterior jaw bones and presenting mostly in the right side of the jaw bone. The results from the present study showed the statistically significant relationship with site of occurrence (maxilla/mandible) and age (p < 0.005). Further, depending on whether it occurs in anterior/mid/posterior site also showed a significant relationship with age (p ≤ 0.001). However, side of occurrence, left or right or site of occurrence, showed no statistically significance with age (p > 0.05). CONCLUSION: Adenomatoid odontogenic tumor occurs more frequently in the second decade of life with a significant female predominance and the commonest site is anterior maxilla. This study revealed few differences on demographic and clinical presentations of adenomatoid odontogenic tumor from some regions of the world.

Low-Grade Myofibroblastic Sarcoma of the Oral Cavity: A Report of Three Cases Illustrating an Emerging Disease in Children.

Low-grade myofibroblastic sarcoma (LGMS) is a mesenchymal tumor of myofibroblasts that occurs more frequently in adults. A series of three cases is presented to illustrate that LGMS may also occur within the oral cavity in children and adolescents. The first case (Case 1) occurred intra-osseously in the mandible, while the remaining two presented as gingival swellings and were purely restricted to soft tissue (cases 2 and 3). The intra-osseous lesion arose in a 7-year-old girl, whereas the gingival lesions were observed in a 12-year-old girl (Case 2) and a 13-year-old boy (Case 3). Histopathologically, all cases were composed of spindle shaped cells arranged into long fascicles showing mild to moderate degree of nuclear atypia. Ki-67 (MIB-1) proliferation activity was relatively low, amounting to 3-5% in all cases. Immunohistochemically, all cases showed smooth muscle actin (SMA) positivity in spindle cells, while desmin, beta catenin, cytokeratin, and CD34 were negative, resulting in a diagnosis of LGMS. In conclusion, current series of three cases of LGMSs that occurred in the oral cavity in a child and two adolescent patients is presented to highlight an emerging disease that requires additional data for further characterization.

A clinico-pathological comparison between mandibular and maxillary ameloblastomas in Sri Lanka.

BACKGROUND: The aim of this retrospective study was to analyse the relative prevalence and the clinico-pathological characteristics of mandibular and maxillary ameloblastomas in Sri Lanka. METHODS: Clinico-pathological features of a total of 286 cases of ameloblastomas were analysed. RESULTS: Out of the 286 cases, 87.8% (251/286) of ameloblastomas occurred in the mandible, while 10.8% (31/286) occurred in the maxilla indicating a ratio of 8:1. In the mandible, 54% (136/251), 40% (100/251) and 6% (15/251) of tumours and in the maxilla, 23% (7/31), 48% (15/31) and 29% (9/31) of tumours were solid/multicystic ameloblastomas (SMA), unicystic ameloblastomas (UA) and desmoplastic ameloblastomas (DA) respectively. No gender predilection was observed in mandibular or maxillary ameloblastomas. Most of the lesions were observed in 2nd to 5th decade of life (mean age 33.2 years). No differences between mandibular and maxillary ameloblastomas were observed with reference to overall cellularity and mitotic activity. Solid/multicystic and UAs showed a predilection to posterior region, while DAs were frequently found in the anterior region of both jaws. Twenty-one percentage (60/286) of ameloblastomas presented with recurrences, and 94% (34/36) of these recurrences were observed in cases treated conservatively. CONCLUSION: In conclusion, mandibular ameloblastomas were more prevalent than maxillary ameloblastomas, while no differences were observed in age or gender distribution between the mandibular and maxillary ameloblastomas. However, higher proportion of DAs and UAs was observed in the maxilla compared with some of the other studies. SMA should be treated with resection to prevent recurrences.

Proliferative Verrucous Leukoplakia of the Gingiva: An Early Lesion Refractory to Surgical Excision.

This report describes a case of proliferative verrucous leukoplakia (PVL) of the gingiva with no discernible aetiology, which presented in a 36-year-old female. The initial nonscrapable gingival lesion was treated with CO2 laser ablation, and the histopathological evaluation was carried out. The presence of koilocytic cells in the superficial epithelium led to immunohistochemical investigations with p16 antibody, which showed strong nuclear positivity and slight cytoplasmic positivity in >50% of the cells with >25% confluency. However, it was not possible to confirm the presence of HPV infection with further investigations due to logistic reasons. The lesion recurred twice within a short time despite the surgical resection following the first recurrence. Thus, this paper presents a case of proliferative verrucous leukoplakia, which demonstrated a significant resistance to routine treatment protocols recommended in the management of such lesions.

Clinico-Pathological Presentations of Cystic and Classic Adenomatoid Odontogenic Tumors.

The objective of the study is to present the clinico-pathological features of cystic and classic adenomatoid odontogenic tumors (AOTs) in order to identify the differences between the two variants of AOT. MATERIALS AND METHOD: The study sample comprised of 41 AOTs, which were categorized into cystic and classic AOTs. Cystic AOTs are diagnosed as such when macroscopic and microscopic evidence of a cyst is present together with histopathological criteria of AOT (WHO-2017). RESULTS: The study sample comprised of eleven cystic and thirty classic AOTs. Eight cystic AOTs were regarded as arising from dentigerous cysts as these lesions were attached to the cemento-enamel junction of the impacted teeth. Though not statistically significant, in contrast to classic AOTs which showed female predilection, cystic AOTs were more prevalent in males. Cystic AOTs tend to present as significantly larger lesions compared to classic AOTs (p < 0.02). In both cystic and classic AOTs, duct-like structures and epithelial whorls were the two most prominent histopathological features present in the majority of tumors. Two AOTs with massive amounts of dentinoid occurred in the mandible and presented as large lesions that eroded cortical bone. None of the 12 patients with follow-up information presented with recurrences. CONCLUSION: Except for the size of the lesion, no significant clinico-pathological differences were observed between cystic and classic AOTs. Therefore the cystic AOTs can be considered as a variant of AOT with enucleation, simple excision, or radical excision as the treatment of choice depending on the extent of the lesion, similar to classic AOTs.

Clinical and demographic characteristics of adenomatoid odontogenic tumors: analysis of 116 new cases from a single center / Características clínicas e demográficas de tumores odontogênicos adenomatoides: análise de 116 novos casos em um único centro

Abstract Introduction The adenomatoid odontogenic tumor is a relatively uncommon odontogenic neoplasm representing about 4.7% of all odontogenic tumors. Objective The aim of this study was to determine the demographic and clinical profile of the adenomatoid odontogenic tumors in a Sri Lankan population. Methods Data gathered from the cases received for a period of 38 years from the Department of Oral Pathology, Faculty of Dental Sciences, University of Peradeniya. Request forms, biopsy reports and electronic data base of the department were used to obtain relevant information. Demographic data including age, gender and location of the tumor were included in the analysis. Results Out of 116 cases of adenomatoid odontogenic tumor, the mean age was 21.02 ± 11.24. It occurs more fre quently in the second decade of life, more prevalent in females, most often associated with the maxilla, predominantly affecting anterior jaw bones and presenting mostly in the right side of the jaw bone. The results from the present study showed the statistically significant relationship with site of occurrence (maxilla/mandible) and age (p< 0.005). Further, depending on whether it occurs in anterior/mid/posterior site also showed a significant relationship with age (p≤ 0.001). However, side of occurrence, left or right or site of occurrence, showed no statistically significance with age (p> 0.05). Conclusion Adenomatoid odontogenic tumor occurs more frequently in the second decade of life with a significant female predominance and the commonest site is anterior maxilla. This study revealed few differences on demographic and clinical presentations of adenomatoid odontogenic tumor from some regions of the world.

Resumo Introdução O tumor odontogênico adenomatoide é uma neoplasia odontogênica relativamente incomum que representa cerca de 4,7% de todos os tumores odontogênicos. Objetivo Determinar o perfil demográfico e clínico dos tumores odontogênicos adenomatoides em uma população do Sri Lanka. Método Os dados foram obtidos dos casos tratados por 38 anos no Departamento de Patologia Oral da Faculty of Dental Sciences, University of Peradeniya. Formulários de solicitação, relatórios de biópsia e o banco de dados eletrônico do departamento foram usados para obter informações relevantes. Dados demográficos, idade, sexo e localização do tumor foram incluídos na análise. Resultados Dos 116 casos de tumor odontogênico adenomatoide, a média de idade foi de 21,02 ± 11,24. Ocorreu com mais frequência na segunda década de vida, e foi mais prevalente no sexo feminino, mais frequentemente associado à maxila, afetou predominantemente os ossos da mandíbula anterior e apresentou-se principalmente no lado direito dos ossos da mandíbula. Os resultados do presente estudo mostraram uma relação estatisticamente significante com o local da ocorrência (maxila/mandíbula) e idade (p < 0,005). Além disso, de acordo com o local de ocorrência, região anterior/média/posterior, também apresentou relação significante com a idade (p ≤ 0,001). Entretanto, nem o lado acometido, direito ou esquerdo, ou o sítio de ocorrência foi estatisticamente significante em relação à idade (p > 0,05). Conclusão O tumor odontogênico adenomatoide ocorre com mais frequência na segunda década de vida, com predominância feminina significativa, e o local mais comum é a maxila anterior. Este estudo revelou poucas diferenças nas apresentações demográficas e clínicas do tumor odontogênico adenomatoide de algumas regiões do mundo.

Diagnostic Approach to Synovial Sarcoma of the Head and Neck Illustrated by Two Cases Arising in the Face and Oral Cavity.

In the head and neck region, synovial sarcomas (SS) are rare tumours. We describe the diagnostic approach to SS based on two cases which developed in a 26-year-old male in the face and in a 53-year-old female on the alveolar mucosa of the upper jaw. The demographic profile of the patients was compatible with the literature. Histopathologically, both tumours presented as unencapsulated spindle cell tumours arranged into short fascicles. Although the chromosomal translocation of t(X;18)(p11.2;q11.2), transducin-like enhancer of split 1 (TLE-1) and SMARCB1 antibodies derived from gene expression studies are considered as the most sensitive makers to diagnose SS, these facilities were not available. Therefore, our cases were diagnosed as monophasic fibrous SS, utilizing a panel of immunohistochemical markers, including cytokeratins, EMA, Bcl-2, and CD99 as positive indicators and CD34, SMA, MYO-D, and S-100 as negative indicators. PAS staining was used to identify glycogen and to exclude spindle cell carcinomas and leiomyosarcoma, while Alcian blue was used to identify myxoid ground substance and to exclude nodular fasciitis. In conclusion, SS, although rare, should be included in the differential diagnosis of spindle cell tumours of the face and oral mucosa.

A Peripheral Dentinogenic Ghost Cell Tumor With Immunohistochemical Investigations and a Literature Review-Based Clinicopathological Comparison Between Peripheral and Central Variants.

The aim of the study was to present a peripheral dentinogenic ghost cell tumor (DGCT) and to describe clinicopathological differences between peripheral and central variants of the tumor using a selected literature review. The case report is based on a swelling present on the alveolar ridge of a 74-year-old edentulous denture wearer. The lesion was diagnosed as a peripheral DGCT after excluding the presence of a central lesion. Immunohistochemical investigations revealed similar cytokeratin expression pattern, with CK14 and MNF116 positivity in both the tumor and the surrounding surface epithelium. However, in contrast, CK19 expression was restricted to less than 5% of the tumor cells. A clinicopathological comparison was compiled using 30 cases of peripheral DGCTs (including the present lesion) and 16 cases of central DGCTs published over a period of 40 years. Accordingly, peripheral lesions were more often found in elderly denture wearers, in relation to mandibular gingiva and alveolar mucosa. None of the lesions had recurred after excision. In contrast, majority of the central lesions were common in younger individuals and showed a striking male predilection. It occurred equally on both jaws, while approximately 50% of the lesions gave rise to recurrences. In conclusion, similar cytokeratin expression in both the tumor and surface epithelium can be used to support oral surface epithelial origin, while CK14 positivity confirms the odontogenic derivation of the peripheral DGCT described in the report. In contrast to central DGCT, the peripheral DGCT is a distinct lesion with characteristic clinicopathological profile and nonaggressive behavior.

Benign Fibrous Histiocytomas of the Oral Mucosa: Report on Three Cases and Review of the Literature.

Benign fibrous histiocytomas (BFH) of the skin are common lesions, although they only rarely involve the oral mucosa. This article presents 3 additional cases of BFH of the oral mucosa, with a review of previously published cases. Although a malignant variant of BFH also exists, the present review focuses only on benign lesions. The clinical presentation, diagnosis, histopathological and immunohistochemical features of BFH are discussed. According to the present analysis, the majority of oral mucosal BFH have occurred in middle-aged and elderly patients, with a slight female predilection. Within the oral cavity, BHF may occur at any mucosal site, including the lips, tongue, buccal mucosa, mandibular and maxillary gingiva as well as the palate. Histopathology is essential to diagnose the lesion, while immunohistochemical investigations may be utilized to exclude the histopathological differential diagnoses such as juvenile xanthogranulomas and nevi. This review also revealed total excision as the treatment of choice for BFH, with a very good prognosis and an extremely low rate of relapse.

Diagnostic dilemma of unicystic ameloblastoma: novel parameters to differentiate unicystic ameloblastoma from common odontogenic cysts.

AIM: Diagnostic criteria that have been specified for unicystic ameloblastomas (UAs) are not always helpful to differentiate these cystic tumors from common odontogenic cysts. The aim of this study therefore was to identify additional histopathological features (other than the features considered for the diagnosis of UA at present) that would be helpful to differentiate UA from odontogenic cysts. METHODS: One hundred histopathologically confirmed unicystic ameloblastomas and 20 cases each of radicular, inflamed dentigerous and non-inflamed dentigerous cysts were selected. Histopathological features of the UAs that are not used as diagnostic criteria at present were identified. RESULTS: Hyperplastic arcading epithelial proliferations with stellate-reticulum-like and vacuolated cells were always seen associated with inflammation in odontogenic cysts, while in UA plexiform-like areas were also seen without inflammation (P < 0.001). In addition, a spiky rete pattern was observed in non-inflamed UA while this pattern was observed only in inflamed odontogenic cysts. Furthermore, spiky retes together with subepithelial hyalinization were usually observed in UAs while only subepithelial hyalinization was observed in non-inflamed dentigerous cysts. CONCLUSIONS: Combinations of histopathological features were identified to differentiate non-inflamed UA from common odontogenic cysts. However, presence of inflammatory changes in UA precludes the use of features identified in the present study for diagnostic purposes.

Relationship between thickness of fibrosis and epithelial dysplasia in oral submucous fibrosis.

AIM: Although oral submucous fibrosis is characterized by fibrosis of the subepithelial connective tissue, the overlying epithelial changes contribute to malignant transformation. Therefore, the aim of the study was to evaluate the relationship between thickness of fibrosis and epithelial changes in oral submucous fibrosis. METHODS: The relationship between thickness of fibrosis and presence or absence of epithelial dysplasia was evaluated in 107 biopsies containing histopathologically-confirmed oral submucous fibrosis. The results were analyzed using Student's t-test or χ(2) -test. RESULTS: Fifty-seven percent (61/107) of oral submucous fibrosis lesions showed a non-dysplastic overlying epithelium, while 43% (46/107) showed varying degrees of epithelial dysplasia. The mean thickness of fibrosis of non-dysplastic lesions was 0.91±0.41 mm (mean ± standard deviation) and ranged from 0.25 to 1.9 mm. However, the mean thickness of fibrosis of dysplastic lesions was 1.17 ± 0.52 mm and ranged from 0.48 to 3 mm. The results revealed a significant increase in the incidence of epithelial dysplasia as the thickness of fibrosis increased (P = 0.004). As such, the lesions that showed increased fibrosis were more likely to present with epithelial dysplasia. CONCLUSIONS: The advancement of fibrosis increases the risk of development of epithelial dysplasia in oral submucous fibrosis.

Review of metastasizing (malignant) ameloblastoma (METAM): pattern of metastasis and treatment.

OBJECTIVES: The rare malignant odontogenic tumor, metastasizing (malignant) ameloblastoma (METAM) is reviewed with the aim of analyzing the pattern of disease and treatment of cervical metastasis based, on 2005 World Health Organization classification. STUDY DESIGN: A total of 65 cases, including reported cases from 1923 to 2009 compatible with the current classification and a new case are reviewed. RESULTS: METAM occurred mostly in lungs (71%), followed by cervical lymph nodes (28%). Female-to-male ratio was 1:1.1. Primary tumor was diagnosed in 28% of cases at ages ≤ 20 years, and maxilla-to-mandible ratio was 1:5.2. The mean disease-free interval and survival for pulmonary metastasis were 14.37 years and 3 years, respectively, and 12.96 years and 6 years for cervical METAM. Five-year survival rate for cervical metastasis treated purely surgically was 71.43%. CONCLUSIONS: According to the available literature, neck dissection is the treatment of choice for cervical METAM. Evidence for the role of chemotherapy and radiotherapy is not conclusive.

A histopathologic comparison between synchronous and single primary oral squamous cell carcinomas.

OBJECTIVE: This study compares synchronous oral squamous cell carcinomas (OSCCs) with single primary OSCCs to assess the histopathologic parameters with a known prognostic significance. STUDY DESIGN: Twenty-eight cases of synchronous OSCCs and a control group of single primary OSCCs were compared for 15 histologic prognostic variables. RESULTS: Results showed significantly less amount of abnormal mitoses (synchronous-1: P = .002; synchronous-2: P = .006) and tumor-induced stroma (synchronous-1: P = .011; synchronous-2: P = .001) in synchronous OSCCs than in single primary OSCCs. Depth of invasion was considerably lower in synchronous OSCCs than in single primary OSCCs (synchronous-1: P = .007; synchronous-2: P = .002). Lymph node metastasis (synchronous-1: P = .051; synchronous-2: P = .051) was found to be rare in synchronous OSCCs compared with single primary OSCCs. CONCLUSION: Synchronous OSCCs show less aggressive histopathologic features than single primary OSCCs.

Epithelial salivary tumors in Sri Lanka: a retrospective study of 713 cases.

OBJECTIVE: The aim of this retrospective study was to evaluate the clinicopathologic data to determine the distribution of epithelial salivary tumors, especially minor salivary tumors, in Sri Lanka. MATERIALS AND METHODS: A total of 713 salivary tumors diagnosed at the Department of Oral Pathology, during the period from 1990 to 2007 were reviewed. RESULTS: Out of the 713 epithelial salivary tumors, 356 (49.9%) were classified as benign and 357 (50.1%) as malignant, indicating a benign-to-malignant ratio of 1:1. The majority of both benign (29%) and malignant (39%) tumors occurred in the minor salivary glands. Malignant tumors were slightly more common in minor salivary glands, indicating a benign-to-malignant ratio of 1:0.75. Among the minor salivary sites, palate was the most frequent location, accounting for 51% of the tumors (246 out of 486). The tumors affected adult patients more commonly, and a slight female predominance (1:1.15) was also evident. Pleomorphic adenoma was the most frequent tumor, representing 38% of all tumors (274 out of 713), followed by mucoepidermoid carcinoma 21.6% (154 out of 713) and adenoid cystic carcinoma 13.5% (96 out of 713). The commonest benign and malignant tumors were pleomorphic adenoma and mucoepidermoid carcinoma in both major and minor salivary glands. CONCLUSION: According to the findings of this study, equal frequencies of benign and malignant tumors indicate higher occurrences of malignancies, especially in the minor salivary glands, in the Sri Lankan population.