Different methods of cell quantification can lead to different results: a comparison of digital methods using a pilot study of dendritic cells in HIV-positive patients.

BACKGROUND: Although new digital pathology tools have improved the positive cell quantification, there is a heterogeneity of the quantification methods in the literature. The aim of this study was to evaluate and propose a novel dendritic cells quantification method in squamous cell carcinoma comparing it with a conventional quantification method. MATERIAL AND METHODS: Twenty-six squamous cell carcinomas HIV-positive cases affecting the oropharynx, lips and oral cavity were selected. Immunohistochemistry for CD1a, CD83, and CD207 was performed. The immunohistochemical stains were evaluated by automated examination using a positive pixel count algorithm. A conventional quantification method (unspecific area method; UA) and a novel method (specific area method; SA) were performed obtaining the corresponding density of positive dendritic cells for the intratumoral and peritumoral regions. The Mann-Whitney U test was used to verify the influence of the quantification methods on the positive cell counting according to the evaluated regions. Data were subjected to the ANOVA and Student's t-test to verify the influence of the tumour location, stage, histological grade, and amount of inflammation on the dendritic cells density counting. RESULTS: The cell quantification method affected the dendritic cells counting independently of the evaluated region (P-value <0.05). Significant differences between methods were also observed according to the tumour features evaluations. CONCLUSIONS: The positive cell quantification method influences the dendritic cells density results. Unlike the conventional method (UA method), the novel SA method avoids non-target areas included in the hotspots improving the reliability and reproducibility of the density cell quantification.

Oropharyngeal carcinoma: what the dentist should know.

HPV-related oropharyngeal carcinoma (OPC) is a clinically and molecularly distinct form of squamous cell carcinoma (SCC) which has recently shown a dramatc increase in global incidence. The aetiology, clinical presentation and overall prognosis differ from conventional tobacco and alcohol related SCC of the oral cavity. OPC is seen in a subset of younger predominantly male patients. Acquisition of high-risk HPV subtypes is related to oral sex practices with multiple partners. OPC originates deep within tonsillar crypts which hinders early clinical detection. Patients present with advanced disease and frequent cervical lymph node metastases. Despite its aggressive nature, the overall prognosis remains excellent compared wth conventional oral SCC. The increased incidence of OPC is of clinical significance to the general dentist and should always be considered in the clinical differential diagnosis in a young, otherwise healthy, patient with persistent cervical lymph node enlargement. Older patients with a history of tobacco usage and alcohol consumption may also present with conventional SCC of the oropharynx. Potentially malignant disease may precede tumour development at this site in such cases. Clinical examination of the oropharynx should therefore be performed as part of routine dental consultation.

HIV/AIDS associated malignancies of the head and neck.

Patients with HIV/AIDS are at increased risk for the development of malignancy. Kaposi's sarcoma, non-Hodgkin's lymphoma and cervical carcinoma in women are regarded as AIDS-defining malignancies. The spectrum of malignancy is, however, changing, particularly where patients receive highly active antiretroviral therapy (HAART). South Africa has the highest number of HIV-infected individuals globally. The possibility of the oral health care worker encountering HIV/AIDS-related pathology therefore seems inevitable. The aim of this article is to heighten the awareness of head and neck malignancies occurring in HIV/AIDS whilst highlighting some of the clinical features in order to facilitate early recognition and diagnosis. It is of clinical significance that in many instances, identification of these malignancies precedes HIV/AIDS diagnosis. Optimal patient management requires close co-operation between the oral health care practitioner and the extended health care team.

Epidemiology of oral squamous cell carcinoma.

The National Cancer Registry (NCR) of South Africa publishes the pathology-based cancer incidence in the country and is the main cancer data source. The data published by the NCR have been used extensively in the development of the draft national guidelines for cancer prevention and control as well as for cancer research. The list of contributing pathology laboratories is fairly inclusive. Data from the NCR and the University of Limpopo, Department of Oral Pathology for the five years 1997-2001 were combined and then filtered for sites in the oral and oropharyngeal region. Age-Standardised Incidence Rates (ASIR) and the Cumulative Lifetime Risk (LR) for males and females in the different population groups were determined. Comprehensive reporting of oral and oropharyngeal cancer incidence will influence the allocation of government resources for prevention and treatment of oral cancers.

Immunohistochemical profile of odontogenic epithelium in developing dog teeth (Canis familiaris).

Tumors of the jaw bones and oral soft tissue are relatively common lesions in dogs. The aim of this study was to find cell markers to differentiate odontogenic epithelium from nonodontogenic epithelium for future research on the pathogenesis and pathology of odontogenic neoplasms in dogs. Keratin 14 and 19 staining was observed in odontogenic and nonodontogenic epithelium, whereas amelogenin and p75 neurotrophin receptor immunoreactivity was observed in certain odontogenic epithelial cells at various stages of development but not in other epithelial cells. Calretinin staining was observed in the alveolar epithelial cells directly overlying the developing tooth germ in 28 of 39 sections (71.8%), as well as the dental laminae in 30 of 35 sections (85.7%) and Serres rests in 24 of 28 sections (85.7%). Focal positivity was detected in the respiratory mucosa, some hair follicles, and fusion epithelium of the palate, but no calretinin staining was observed in other oral epithelial cells; therefore, calretinin has potential to be utilized as a marker to differentiate odontogenic form nonodontogenic epithelium.

Chronic ulcerative stomatitis: a distinct clinical entity?

Chronic ulcerative stomatitis (CUS) is a mucocutaneous disorder which is characterised by persistent oral mucosal ulceration. The clinical appearance is often reminiscent of oral lichen planus (OLP) leading to erroneous diagnoses. The immune mediated inhibition of the CUS protein (CUSP) is implicated in the pathogenesis of CUS. CUSP acts as an anti-apoptotic protein and when its action is prevented it may result in significant epithelial injury. The objective or this article is to present the first documented case of CUS in South Africa, with relevant reference to current international literature. CUS should be considered in patients previously diagnosed with OLP but who are unresponsive to glucocorticosteroid therapy. The condition can be successfully managed using hydroxychloroquine.

Concomitant Congenital Intraoral Dermoid Cyst and Heterotopic Gastrointestinal Cyst.

Sublingual dermoid cysts and oral heterotopic gastrointestinal cysts are well-documented causes of sublingual swellings in infants. However, the simultaneous occurrence of both cysts is an extremely rare phenomenon, with only two previous cases reported in literature. We present a case of 1-month-old neonate with a cystic ventral tongue mass that on histologic examination showed a dermoid cyst with co-existing heterotopic gastric-type epithelium in the wall. Additional histochemical stains revealed focal areas of colonic metaplasia within the heterotopic gastric epithelium. CDX2 immunohistochemical staining confirmed derivation from colonic epithelium.

Rhino-orbitocerebral entomophthoramycosis.

Conidiobolus coronatus is recognized as a human pathogen causing subcutaneous fungal infection of the face in immunocompetent patients. The disease process is usually benign. We report, what we believe to be the first case of intracranial extension of C. coronatus producing rhino-orbitocerebral syndrome, and subsequent dissemination of C. coronatus in an immunocompetent patient.

The role of DNA ploidy and Ki-67 in the grading of mucoepidermoid carcinomas.

BACKGROUND: The grading of mucoepidermoid carcinomas (MEC) is based on subjective microscopic evaluation of the prevalence of cell types as well as features of atypia and aggressiveness. Our study was aimed at evaluating the role of high-resolution DNA flow cytometry and Ki-67 expression in the grading of MEC. MATERIALS AND METHODS: Fifty-five cases of intraoral and major salivary gland tumours, diagnosed as MEC, were retrieved and the grading system proposed by Brandwein et al. applied. RESULTS: Forty-nine per cent of our sample was graded as high, 35% as intermediate and 16% as low. Eighty-nine per cent of the high-grade MEC showed aneuploid DNA cell populations, while 88% of the diploid tumours were graded as intermediate or low. The mean Ki-67 positivity was significantly different between the high and intermediate grade tumours and between the aneuploid and diploid tumours. CONCLUSION: This study showed that high-resolution DNA flow cytometry of archival paraffin-embedded tissue is accurate in the grading of MEC and can be used with Ki-67 expression as an additional diagnostic tool.

In vitro comparison of three materials as apical sealants of equine premolar and molar teeth.

REASONS FOR PERFORMING STUDY: Surgical endodontic therapy is a conservative dental technique used in horses with some degree of clinical success. Failure of this procedure can partially be explained by inadequate sealing of the root apices with resultant microleakage in the periapical area. OBJECTIVES: To assess and compare in vitro sealing ability of 3 different dental restorative materials used as apical sealants during equine surgical endodontics. METHODS: Thirty extracted equine cheek teeth were divided randomly into 3 groups and subjected to apicoectomy and apical sealing using 3 materials: reinforced zinc oxide-eugenol cement; intermediate restorative material (IRM); a resin-modified glass ionomer; and amalgam. After apical sealing, the teeth were submerged in a solution of Procion Brilliant Cresyl Blue stain for a period of 7 days. The teeth were then washed, embedded in resin, sectioned and assessed microscopically for dye leakage around the apical restorations. RESULTS: Although the materials proved effective as apical sealants, some dye leakage was encountered in all 3 groups with no statistical difference (P = 0.114). CONCLUSIONS AND POTENTIAL RELEVANCE: IRM, a resin-modified glass ionomer and amalgam all showed comparative features as apical sealants when used in vitro in equine teeth. IRM is currently regarded as the superior material in clinical situations due to its ease of handling and lesser sensitivity to environmental moisture during placement compared to the other 2 materials.

Diagnosis and treatment of primary intraoral leiomyosarcomas in four dogs.

This paper describes the clinical and pathological features, diagnosis and management of primary intraoral leiomyosarcomas in the oral cavity of four dogs; they involved the gingivae of the rostral maxilla and mandible, the mucosa of the upper lip and the soft palate. Their features are compared with the those of leiomyosarcomas commonly encountered in the gastrointestinal tract of dogs. Two of the dogs responded well to surgical treatment; one died after its airways were obstructed by a large palatal tumour; and the fourth was lost to follow-up after its owners declined treatment.

Is the human papillomavirus a mutual aetiological agent in oral and cervical squamous cell carcinoma?

BACKGROUND: Oncogenic HPV-types are the most important risk factor in cervical SSC and have also been implicated in the aetiology of OSSC. This evidence of infection at different anatomical sites suggests systemic susceptibility that implies that different expressions of disease should more or less correlate over long periods of time. MATERIALS AND METHODS: This was undertaken to establish whether any correlation could be found between the incidence of cervical SCC and OSCC in females and OSSC in males in South Africa, over a ten-year period, 1986 to 1995. RESULTS: Several moderate to strong correlations, which ranged from significant (p < 0.05) to highly significant (p < 0.01), between the incidence of cervical SSC and OSSC in the Black and Coloured populations, and OSSC in the White male population, were found. CONCLUSION: These results support the idea of systemic susceptibility, and infection through a common agent such as HPV, contributing to the cause of SSC.

Epstein-Barr virus strain characterisation in South African patients with nasopharyngeal carcinomas.

UNLABELLED: Epstein-Barr virus (EBV) has been implicated in various diseases, among others, nasopharyngeal carcinoma (NPC). In this study we investigated the frequency and subtype distribution of EBV in 39 NPCs. The presence of EBV was detected by using a nested PCR to amplify the Bam Hl W-fragment of the genome. Two regions were targeted for subtype analysis, namely the EBNA-2A and EBER regions. PCR was used to amplify these regions, and the EBER region was sequenced to detect subtype specificity. The results showed that EBV could be detected in 82% (31/38) of the tumours. In 15 of these, EBNA subtypes could be identified of which 14 were subtype A and one tumour had both subtypes A and B present. The EBER region was amplified in 21 samples. The majority of cases (18/21) demonstrated a mutation profile which consisted of 5 type B and one type A mutations. The consensus type is therefore type B. IN CONCLUSION: a strong association was found between EBV and NPCs in our group of patients and their "consensus" genotype was A/B based on the two genome areas investigated.

Human papillomavirus DNA in oral squamous cell carcinomas from an African population sample.

BACKGROUND: The incidence of oral squamous cell carcinoma (OSCC) is on the increase in developing countries. MATERIALS AND METHODS: Formalin fixed paraffin embedded blocks of OSCCs from a Black South African population sample of peri-urban and rural origin were selected as follows: Group 1 - 57 OSCCs with a mean age of 59 years; Group 2 - 43 OSCCs all cases younger than 40 years; Group 3 - 46 OSCCs with blocks containing only tumour tissue without any normal epithelium and Group 4, a control group of 38 non-neoplastic epithelial lesions. Type specific primers were used in a standard PCR to amplify a segment of the E6 region of HPV 6, 11, 16 and 18. RESULTS: HPV 11 and 16 DNA were found in one sample each from groups 1 and 2 respectively. CONCLUSION: HPV is not an etiologic factor in the development of OSCC in the population studied.

Correlation between p53 gene mutation, p53 protein labeling and PCNA expression in oral squamous cell carcinomas.

BACKGROUND: The prevalence of oral squamous cell carcinoma (OSCC) among the Black community in South Africa is unacceptably high. The association between p53 protein, and PCNA overexpression and the presence of p53 gene mutations was evaluated. MATERIALS AND METHODS: One hundred and ten formalin-fixed, paraffin-embedded blocks of OSCC were selected for immunohistochemical studies for p53 protein and PCNA expression using the DO-7 and PC10 monoclonal antibodies, respectively. DNA was extracted from fifty-five blocks and exons 5 to 9 of the p53 gene were amplified with nested primers, thereafter sequencing was performed to confirm the presence of mutations detected by single stranded conformational polymorphism. RESULTS: Fifty-six cases (51%) showed p53 expression, while fourteen mutations (25%) were detected. A significant difference was found between the PCNA index in p53 positive and p53 negative tumors while the mean PCNA index for the tumors with p53 mutations was not significantly different from the tumors without mutations. CONCLUSIONS: No association between p53 protein overexpression and p53 gene mutations could be demonstrated.

Warthin's tumour is not an Epstein-Barr virus related disease.

BACKGROUND: The histogenesis of Warthin's tumour (WT) is controversial. A possible role for Epstein-Barr virus (EBV) has been suggested. MATERIALS AND METHODS: Twenty formaldehyde-fixed, paraffin-embedded blocks of WT from the parotid gland were examined for the presence of EBV. In situ hybridisation was performed using EBV encoded small nuclear RNAs (EBER1/2) probes labelled with fluorescein isothiocyanate. An EBV-positive P3HR-1 cell line processed to paraffin wax was used as a positive control and a brain section as negative control. RESULTS: EBER1/2 could not be found in the neoplastic epithelial cells in any of the tumours nor in the adjacent normal parotid tissues. Individual positive lymphocytes were present in 7 tumours. CONCLUSIONS: These results indicated that EBV is not involved in the pathogenesis of WT.