Diagnosis of oral potentially malignant disorders: Overview and experience in Oceania.

The diagnosis and management of oral potentially malignant disorders (OPMD) should be the same the world over, but there are important nuances in incidence, aetiological factors, and management opportunities that may lead to differences based on ethnogeography. In this review, we update and discuss current international trends in the classification and diagnosis of OPMD with reference to our experience in various regions in Oceania. Oceania includes the islands of Australia, Melanesia (including Papua New Guinea, Fiji, Solomon Islands, Micronesia and Polynesia (including New Zealand, Samoa, Tonga) and hence has diverse populations with very different cultures and a range from well-resourced high-population density cities to remote villages.

The Risk of Oral Cancer among Different Categories of Exposure to Tobacco Smoking in Sri Lanka

Background: The global incidence of oral squamous cell carcinoma (OSCC) is on the rise with no improvement seen in survival rates. Tobacco consumption varies depending on geographic location, ethnicity and culture. The present case-controlled study aimed to determine the relative risk of OSCC for different tobacco consumption patterns in a selected Sri Lankan population. Methods: One hundred and five patients with histopathologically confirmed OSCC attending the National Cancer Institute (Apeksha Hospital) of Sri Lanka and 210 age and gender-matched controls from the community responded to an interviewer-administered questionnaire regarding their smoking and betel-quid chewing (with/ without smokeless tobacco) habits were included in the study. The odds ratios (OR) and 95% confidence intervals (CI) were calculated. p<0.05 was considered as statistically significant. Results: The overall risk of OSCC increased 2.93-fold for smokers. Those smoking two packets of cigarettes or more per day (OR=5.56; 95% CI-2.822- 10.984; p=0.000) had more than double the risk of OSCC than those smoking 1-2 packets per day. Smoking for more than 20 years had a 3.4-fold risk of OSCC. Consumption of betel quid containing tobacco (smokeless tobacco) had a 4.26-fold higher risk for OSCC (OR=4.26; 95% CI-2.21-8.21; p=0.000), and the risk increased when all four ingredients (betel leaf, slaked lime, areca nut, and tobacco) were consumed together (OR=4.26; 95% CI-2.34-7.74; p=0.000). The combined effect from concurrent smoking and betel chewing emerged as the highest risk for OSCC (OR=15.34) which significantly exceeded the risks evident for the two habits practised in isolation from each other. Conclusions: Use of smokeless tobacco, consumption of all four ingredients together, duration of smoking, the number of cigarettes smoked per day and combined consumption of betel quid and smoking are significant risk factors in the development of OSCC among Sri Lankans.

Immunohistochemical and immunofluorescence expression profile of lymphatic endothelial cell markers in oral cancer.

Lymphangiogenesis makes an important contribution to the tumour microenvironment (TME), but little is known about this in oral squamous cell carcinoma (OSCC). Archival formalin-fixed paraffin-embedded specimens (28 OSCC, 10 inflamed and 6 normal oral mucosa controls) were processed using immunohistochemistry (IHC) with antibodies against lymphatic markers D2-40 (podoplanin), LYVE-1, VEGFR3 and Prox1. After the endothelial cells had been highlighted by the various markers for lymphatic endothelium, the positive stained cells and vessels were identified and counted in a systematic manner to determine microvessel density. Double-labelling immunofluorescence (DLIF) was used to investigate the specificity of D2-40 and LYVE-1 to lymphatic endothelial cells (LECs) as opposed to blood ECs. There was higher D2-40 and Prox1 lymphatic vessel density (P = .001) in the OSCC group when compared with both control groups. Some malignant keratinocytes expressed lymphatic markers, as did a much smaller number of epithelial cells in the control groups. DLIF showed that no vessels co-expressed D2-40/CD34 or LYVE/CD34. Some D2/40+ LVs were LYVE- . D2-40 was the most specific LEC marker in OSCC tissues. These results establish that the OSCC TME contains significantly more lymphatic vessels expressing D2-40 and Prox1 than the control groups, which may play a role in facilitating lymphatic invasion and metastases.

The relative frequency of paediatric oral and maxillofacial pathology in New Zealand: A 10-year review of a national specialist centre.

BACKGROUND: There has been no previous report of the prevalence of paediatric oral and maxillofacial pathology in a New Zealand oral pathology diagnostic service. AIM: The aim of this study was to review cases of paediatric oral pathology to determine relative frequencies of oral lesions in this age group. DESIGN: Paediatric oral pathology cases (≤15 years of age) received between 2007 and 2016 were retrieved from the electronic database of the Oral Pathology Centre, University of Otago. Data collected included diagnoses (categorised into 12 groups), age at diagnosis, and gender. The prevalence of each diagnosis was calculated in terms of percentage of all diagnoses made. Male-to-female ratio and mean age at diagnosis were also determined. RESULTS: A total of 1139 paediatric cases were identified representing 5.2% of all cases. The most common diagnostic group was salivary gland pathology (25.4%), followed by dental (24.8%) pathology. The most prevalent lesion was mucocoele (23%), followed by dental follicle (14.1%). Malignancies were rare with only two cases identified. CONCLUSION: The findings provide an insight into the prevalence of paediatric oral pathology for clinicians. Mucocoele was the most common diagnosis made, suggesting a high prevalence of soft tissue injury as a main presenting concern warranting diagnosis and management through biopsy.

The nexus between periodontics and oral pathology.

A wide variety of lesions may arise from the oral mucosa, fibrous connective tissue, bone and cementum of the periodontium. The commonest pathology occurs as a result of bacterial infection and is very well known to dentists and periodontists, but rarer conditions present as gingival pathology. The pathogenesis of these conditions ranges from genetic to traumatic to immunological to neoplastic, and includes benign, malignant and metastatic lesions. This paper outlines some of these conditions and describes how the periodontist and oral pathologist can work together using a framework, and how with careful consideration of the clinical features and the use of appropriate special tests, including obtaining an adequate tissue specimen, a timely and accurate diagnosis can be obtained.

Metastases to the oral region from pleural mesothelioma: Clinicopathologic review.

BACKGROUND: Malignant mesothelioma is a rare neoplasm that usually develops after exposure to asbestos and particularly involves the pleural cavity. It has a poor prognosis with aggressive local invasion and metastatic spread. METHODS: The literature relating to malignant mesothelioma metastatic to the oral region was reviewed. RESULTS: In all, 14 cases of malignant mesothelioma metastatic to the oral cavity were found. All were from pleural mesotheliomas, the tongue was the most common site of metastasis (8/14), and most metastases (9/13) were of the epithelioid type. The newly reported case is only the second report of a mesothelioma metastasizing to the buccal mucosa. It showed strong immunopositivity for keratin markers, vimentin, calretinin, and Wilms tumor product-1. CONCLUSIONS: The incidence of mesothelioma is predicted to continue to increase for at least another decade. Clinicians and pathologists should be aware of this lesion and its propensity to metastasize to the oral cavity.

A double-clear variant of epithelial-myoepithelial carcinoma of the parotid gland.

The hallmark of the histology of epithelial-myoepithelial carcinoma (EMC) is the presence of a regular repetitive mixture of bilayered duct-like structures with an outer layer of myoepithelial cells and inner ductal epithelial cells. Clear cell change in the myoepithelial component is common, but clearing of both cell types, giving an impression of a monocellular neoplasm, is rare. A parotid biopsy was received from an 83-year-old male and subject to routine histologic processing for conventional staining and immunohistochemistry. The encapsulated tumour was composed of sheets of PAS/diastase negative clear cells, separated by fibrous septae. The clear myoepithelial cells were positive for S-100 protein, SMA, and p63 and negative for CK19 and surrounded CK19-positive luminal cells. It is important to utilise immunohistochemistry to differentiate this tumour from others with a similar histologic pattern. Information about the behaviour of the double-clear EMC is limited since there are few cases reported.

Facial Fractures in Kajang Hospital, Malaysia: A 5-Year Review.

OBJECTIVE: The objective of this study was to determine the demographic data as well as other relevant data pertaining to the management of patients with maxillofacial injury in a Malaysian government regional hospital. STUDY DESIGN: Medical records of 313 patients who sustained maxillofacial injury treated in Kajang Hospital, Selangor, Malaysia over a 5-year period (1998-2002) were collected. Data regarding age, gender and race, etiology of injury, site of injury, other associated injuries and treatment undertaken were analyzed. RESULTS: Two hundred and forty-nine male (79.6%) and 64 female patients (20.4%) were treated for maxillofacial trauma. The patients' age range from 1 to 67 years old, with a median age of 23 years old. A high number of Malays (60.1%) sustained maxillofacial injury, followed by Indians (16%), Chinese (13.4%) and other races (10.5%). Road traffic accident was the main etiology for maxillofacial injury with 230 cases (73.5%), followed by fall (16.6%), assault (5.4%), industrial accident (2.6%), sports injuries (0.6%) and others (1.3%). Mandibular fractures were the most common, occurring in 83.1% of the cases while the midfacial fractures accounted for 16.9%. Majority of patients were treated with closed reduction and intermaxillary fixation (88.1%) and 11.9% underwent open reduction and internal fixation. CONCLUSION: Road traffic accident involving motorcyclists was the main cause of maxillofacial trauma in Malaysia. The most common facial fracture was the mandibular fracture. Non-surgical manipulation of fracture was the most common treatment carried out in this hospital.