Epithelioid Haemangioendothelioma of the mandibular gingiva: case report and literature review

INTRODUCTION

Epithelioid hemangioendothelioma (EHE) is a rare vascular neoplasm that exhibits the potential for recurrence and metastasis but rarely involves the oral cavity.

PRESENTATION OF CASE

We report the management and long term follow up of recurrent EHE in a 23- year-old woman. The lesion initially presented as a small area of erythematous gingival swelling with localised bone loss around the lower anterior teeth. It was treated by buccal and lingual stripping of the gingival tissues. The patient suffered local recurrence after 7 years and was treated with a wider surgical excision of the buccal and lingual gingivae, conserving the adjacent teeth and bone with an excellent cosmetic outcome. Over 21 years later, there have been no further recurrences.

DISCUSSION

This case highlights the management challenges of EHE and is the only case in the literature to have reported a case of mandibular gingivae with a long review period of 21 years.

CONCLUSION

Oral EHE is an unpredictable lesion with a relatively benign course, unlike non-oral EHE where up to one third of cases may metastasise. Because of the propensity to recur locally after excision and curettage, a wide local excision with close clinical follow has been suggested in the literature as the treatment of choice for oral lesions. However, the lack of metastases from oral lesions, the small size, mandibular site and bland histology in this case suggests that a limited soft tissue excision and bone curettage, with long term follow-up would be appropriate for similar gingival lesions in future.

Serum concentration of total soluble CD44 is elevated in smokers

Soluble CD44 isoforms have been reported as markers of specific malignancies and inflammatory diseases. However, recent reports suggest tobacco smoking may lead to an elevation in the circulating concentration of specific CD44 variants. We, therefore, investigated the effect of smoking status on circulating levels of total sCD44. Total soluble CD44 was measured by enzyme-linked immunosorbent assay in the serum of two age- and gender-matched groups consisting of smokers (n = 19) and non-smokers (n = 20). Smoking status was confirmed by analysis of serum cotinine. The concentration of total sCD44 was found to be significantly elevated in smokers compared with non-smokers (p = 0.025). The observation that total sCD44 concentration is raised in smokers may have relevance to the aetiology of smoking-associated diseases. The effect of smoking on sCD44 concentrations should be considered when assessing the role of sCD44 as a marker of inflammatory disease, cancer, or other disease processes.

Apoptin induces apoptosis by changing the equilibrium between the stability of TAp73 and ΔNp73 isoforms through ubiquitin ligase PIR2

Apoptin, a protein derived from the chicken anaemia virus, induces cell death in various cancer cells but shows little or no cytotoxicity in normal cells. The mechanism of apoptin-induced cell death is currently unknown but it appears to induce apoptosis independent of p53 status. Here we show that p73, a p53 family member, is important in apoptin-induced apoptosis. In p53 deficient and/or mutated cells, apoptin induced the expression of TAp73 leading to the induction of apoptosis. Knockdown of p73 using siRNA resulted in a significant reduction in apoptin-induced cytotoxicity. The p53 and p73 pro-apoptotic target PUMA plays an important role in apoptin-induced cell death as knockdown of PUMA significantly reduced cell sensitivity to apoptin. Importantly, apoptin expression resulted in a marked increase in TAp73 protein stability. Investigation into the mechanisms of TAp73 stability showed that apoptin induced the expression of the ring finger domain ubiquitin ligase PIR2 which is involved in the degradation of the anti-apoptotic ∆Np73 isoform. Collectively, our results suggest a novel mechanism of apoptin-induced apoptosis through increased TAp73 stability and induction of PIR2 resulting in the degradation of ∆Np73 and activation of pro-apoptotic targets such as PUMA causing cancer cell death.

Grading oral epithelial dysplasia: analysis of individual features

BACKGROUND

Assessing epithelial dysplasia to predict malignant transformation remains problematic in many tissues because grading systems are poorly structured and individual features poorly defined. Dysplasia grading is criticised for lack of reproducibility and poor predictive value. Grading systems for upper aerodigestive tract dysplasia have evolved over several decades and are not supported by good outcome experimental data.

METHODS

 This study analysed the individual features of dysplasia in 86 oral dysplastic lesions and determined the reproducibility of scoring for each, and correlated them with other features and clinical factors using complex clustering analyses.

RESULTS

A uniform pattern of dysplasia was found in 37 lesions, focal dysplasia in 36 and in 13 lesions dysplasia formed complex discontinuous patterns. There was wide variation in reproducibility of scoring of individual features and many, including thickness, some types of rete morphology, basaloid cell anisonucleosis, basal dyscohesion, and dyskeratosis as deep single cells correlated with sub-sites. Rete morphology, type of keratinisation, hyperchromatism of the basaloid compartment, prickle cell anisonucleosis and extension down salivary ducts correlated with smoking. Conventional grading and oral intraepithelial neoplasia (OIN) grading by 'thirds affected' showed strong correlation overall but scores obtained with the OIN system tended to a higher grade at all sites except soft palate/fauces. There was poor correlation between the systems for moderate dysplasia and also severe dysplasia at some sites. Individual features could not be shown to cluster to form distinct patterns of dysplasia.

CONCLUSIONS

These variations may account in part for the lack of reproducibility and poor predictive value of the grading systems in current use and could inform the design of future grading systems.

Impact of WWOX alterations on p73, ΔNp73, p53, cell proliferation and DNA ploidy in salivary gland neoplasms

OBJECTIVE

WWOX gene is altered in a variety of neoplasms. Wwox is pro-apoptotic through interaction with p73 and may be involved in chromosomal stability by interaction with p73 and p53. The aims of this study were to characterize WWOX transcription, methylation status and immunoexpression in salivary neoplasms and to determine whether these were associated with p73, p53, cell proliferation and DNA ploidy.

MATERIALS AND METHODS

Seven malignant and 21 benign fresh salivary neoplasms were included. WWOX expression was determined by RT-PCR and sequencing of transcripts, quantitative PCR and immunohistochemistry. Methylation-specific PCR was used to assess the methylation of its first exon. For p73, ΔNp73, p53 and ki67 immunohistochemistry and ploidy analysis, 29 malignant samples from archives were included.

RESULTS

No consistent pattern of WWOX exon 1 methylation was found, but aberrant and novel transcripts were observed in 17/28 neoplasms; 55% of tumours showed reduced WWOX RNA. WWOX RNA levels were associated with p53 immunopositivity. Immunohistochemical Wwox expression did not correlate with methylation status, p53 or p73 expression or proliferation. p73, proliferation and DNA ploidy were associated with malignant phenotype.

CONCLUSION

Aberrant WWOX transcription and decreased expression are frequent in salivary neoplasms and WWOX transcription is associated with p53 staining.

PML involvement in the p73-mediated E1A-induced suppression of EGFR and induction of apoptosis in head and neck cancers

Epidermal growth factor receptor (EGFR) tyrosine kinase is commonly overexpressed in human cancers; however, the cellular mechanisms regulating EGFR expression remain unclear. p53, p63 and p73 are transcription factors regulating many cellular targets involved in controlling the cell cycle and apoptosis. p53 activates EGFR expression, whereas TAp63 represses EGFR transcription. The involvement of p73 in the regulation of EGFR has not been reported. Here, a strong correlation between EGFR overexpression and increased levels of the oncogenic DeltaNp73 isoform in head and neck squamous cell carcinoma (HNSCC) cell lines was observed. Ectopic expression of TAp73, particularly TAp73beta, resulted in suppression of the EGFR promoter, significant downregulation of EGFR protein and efficient induction of cell death in all six EGFR-overexpressing HNSCC cell lines. EGFR overexpression from a heterologous LTR promoter protected lung cancer cells from TAp73beta-induced EGFR suppression and apoptosis. Expression of TAp73beta efficiently induced promyelocytic leukaemia (PML) protein expression and PML knockdown by shRNA attenuated the downregulation of EGFR and induction of apoptosis by p73 in HNSCC cells. Furthermore, PML was found to be important for E1A-induced suppression of EGFR and subsequent killing of HNSCC cells. Our data therefore suggest a novel pathway involving PML and p73 in the regulation of EGFR expression.

DNA ploidy in proliferative verrucous leukoplakia

Proliferative verrucous leukoplakia (PVL) is a clinicopathologically distinctive form of oral leukoplakia presenting with multifocal flat, nodular and verrucous lesions that progress inexorably to squamous carcinoma. The aims of this investigation were to describe the clinical and histopathological features of six cases of PVL and to determine whether lesional epithelium demonstrates DNA ploidy anomalies prior to malignant transformation. The clinical and pathological features of six patients were reviewed and all biopsy specimens were subjected to image-based DNA ploidy analysis. The female:male ratio was 5:1 and the average age on first biopsy was 66 years. Only one patient reported both tobacco smoking and alcohol intake. The most frequently affected sites were alveolar ridge and/or gingiva (6/6), buccal mucosa (3/6), palate (3/6), tongue (2/6), buccal sulcus (2/6), and lip (1/6). Three patients developed multiple primary carcinomas, either invasive or verrucous. A ploidy anomaly at any oral site would have predicted malignant transformation in four cases and probably in a fifth for whom DNA ploidy failed to meet diagnostic criteria but was suspicious of aneuploidy. The site of transformation was predicted by ploidy and histopathology for three carcinomas and a further carcinoma showed severe dysplasia and a suspicious ploidy result in adjacent tissue. Both conventional histopathology and DNA ploidy proved effective in predicting the site of transformation in this limited series.

Heterogeneity, histological features and DNA ploidy in oral carcinoma by image-based analysis

Oral squamous carcinomas appear heterogeneous on DNA ploidy analysis. However, this may be partly a result of sample dilution or the detection limit of techniques. The aim of this study was to determine whether oral squamous carcinomas are heterogeneous for ploidy status using image-based ploidy analysis and to determine whether ploidy status correlates with histological parameters. Multiple samples from 42 oral squamous carcinomas were analysed for DNA ploidy using an image-based system and scored for histological parameters. 22 were uniformly aneuploid, 1 uniformly tetraploid and 3 uniformly diploid. 16 appeared heterogeneous but only 8 appeared to be genuinely heterogeneous when minor ploidy histogram peaks were taken into account. Ploidy was closely related to nuclear pleomorphism but not differentiation. Sample variation, detection limits and diagnostic criteria account for much of the ploidy heterogeneity observed. Confident diagnosis of diploid status in an oral squamous cell carcinoma requires a minimum of 5 samples.

British Society for Oral and Maxillofacial Pathology, UK: minimum curriculum in oral pathology

This paper describes a minimum curriculum in oral pathology for undergraduate dental education in the United Kingdom prepared by the Teachers Group of The British Society of Oral and Maxillofacial Pathology. Curricular development in UK dental schools is overseen by the General Dental Council (GDC), the Quality Assurance Agency for Higher Education (QAA) and the European Union. These organisations define the framework for education and learning outcomes but provide little or no detailed guidance on syllabus or curriculum. This recommended minimum curriculum has been drawn up by a consensus process involving teachers of oral pathology from all 13 UK and one Irish dental schools and is cross-referenced to the GDC and QAA published requirements for undergraduate dental education.

Clinico-pathological conference 2002

INTRODUCTION

Six cases are reported, each presented at the 11th Biennial Congress of the International Association of Oral Pathologists as an instructive case for differential diagnosis on the basis of clinical, imaging or histological features.

CLINICAL PICTURE

Case diagnoses included a large, possibly intraosseous, myofibroma presenting with an oral mass; Langerhans cell histiocytosis with facial skin lesions; an intraosseous vascular hamartoma of the maxilla with worrying radiological features; an unusual mixed radiolucency of the jaw caused by cemento-ossifying fibroma; an osteosarcoma of the posterior mandible causing a well-defined radiolucency and an intraoral squamous cell carcinoma in a child.

Basal cell adenocarcinoma in minor salivary glands

Basal cell adenocarcinoma is a rare and relatively recently characterized malignant salivary gland tumour, the malignant counterpart of basal cell adenoma. Diagnosis depends on finding features similar to adenoma but with an infiltrative growth pattern and exclusion of adenoid cystic carcinoma, sialoblastoma and basaloid squamous carcinoma. Basal cell adenocarcinoma is very rarely reported in minor salivary glands. We report three cases of basal cell adenocarcinoma affecting the labial, buccal and palatal minor salivary glands. One recurred following complete removal but with lesional disruption and further local wide excision appeared curative. A further lesion failed to recur in 5 years' follow-up despite marginal excision and a third after 3 years' follow-up. Basal cell adenocarcinoma is considered a low-grade malignancy, and in the minor glands wide excision and radiotherapy are recommended. However, the reported lesions appear to have a more indolent behaviour than previously reported lesions in minor glands.

Expression of ICAM-1 and E-selectin in gingival tissues of smokers and non-smokers with periodontitis

BACKGROUND

Tobacco smoking affects systemic concentrations of soluble intercellular adhesion molecule (ICAM)-1, but its effect on local expression of adhesion molecules in gingival tissue has not been studied previously.

METHODS

E-selectin and ICAM-1 expression on small blood vessel endothelia in gingival biopsies obtained from smokers (n=17) and non-smokers (n=17) with periodontitis was examined with immunohistochemistry. Blood vessels were identified with monoclonal antibody for von Willebrand's factor.

RESULTS

A significantly larger number of vessels were observed in inflamed tissues of non-smokers than smokers (P<0.05). The number and proportion of vessels expressing both ICAM-1 and E-selectin was greater in sites with inflammation compared to non-inflamed sites in both smokers and non-smokers (P<0.05). The proportion of the total number of vessels expressing ICAM-1 in non-inflamed sites was greater in non-smokers compared with smokers (P<0.05).

CONCLUSIONS

These results suggest that the inflammatory response in smokers with periodontitis may not be accompanied by an equivalent increase in vascularity. Reduced ICAM-1 expression in non-inflamed areas of smokers could reflect a systemic effect of tobacco smoking on ICAM-1 independent of inflammation.

Rapid growth of giant cell granuloma in pregnancy treated with calcitonin

The giant cell granuloma of the jaws is a benign osteolytic lesion that may be treated by curettage, intralesional corticosteroids, or calcitonin. These medical treatments may be particularly useful when lesions arise in the immature facial skeleton, recur, or enlarge very rapidly-the last two situations being recognized complications of pregnancy. In this study, a patient is presented with a central giant cell lesion of the maxilla that switched from a relatively indolent growth pattern to become a rapidly enlarging and destructive lesion in the maxilla almost immediately after the patient became pregnant. Although calcitonin treatment is normally avoided in pregnancy, it proved highly effective, caused no obstetric or fetal side effects, and was not contraindicated by renal failure due to lupus nephritis. Histologically, the lesion was converted to a fibro-osseous lesion-like appearance. On the basis of the results of this case, calcitonin appears to be a safe, effective, and conservative treatment for giant cell granulomas that enlarge rapidly during pregnancy.

Participating dentists' assessment of the pilot regional online videoconferencing in dentistry (PROVIDENT) project

OBJECTIVE

To assess the educational effectiveness of delivering continuing professional education (CPE) from dental schools to small groups of dentists at distant sites via videoconferenced links using relatively inexpensive equipment and ISDN2 links.

DESIGN

41 videoconferences between the four campuses of London Dental Schools and postgraduate centres in South East England were assessed using a pre-piloted questionnaire which contained open and specific questions. The questionnaire was given to all participants at the end of each videoconference. Answers to the specific questions were graded using the Likert scale.

RESULTS

40 of the 41 videoconferences were completed satisfactorily and were attended by 257 participants, all of whom completed questionnaires. However, no individual question was answered by all the participants. Of the responses 90% were positive on the topics of appropriateness of the teaching material for delivery by videoconference and of its educational level. 90% of responses also indicated a wish to attend further videoconferences and satisfaction at avoiding the need to travel to London for similar educational activity. 87% rated the lecturers as good or excellent in their use of the medium. 85% of responses indicated that the question and answer sessions within the videoconferences were useful and 82% that the visual aids enhanced the sessions. The technical aspects of the videoconferences were rated positively but to a lesser extent than the educational aspects with 69% of positive responses for visibility of visual aids, 54% for sound quality and 76% for the lecturers use of the technology. The technical aspects of the videoconferences improved during the pilot study. In response to the open questions, participants stated that they found the most useful aspects of the videoconferences were not having to travel, access to first rate lecturers, the discussions and the opportunity to interact with experts.

CONCLUSIONS

The participants in this pilot study were positive about the use of videoconferencing to deliver educational material from dental schools to small groups. Once the technology has improved, this medium has the potential to provide CPE for dentists at work or at home in response to their specific needs.

A study of videoconferencing for postgraduate continuing education in dentistry in the UK--the teachers' view

Videoconferencing is an established method for providing medical education over long distances. Our aims were to assess the feasibility of videoconferencing in dental postgraduate education, to evaluate its practicability, teacher satisfaction and evaluate equipment. Twenty-seven teachers from the 4 London Dental Schools provided 41 postgraduate dental education sessions on a range of topics to regional postgraduate centres and dental practices as part of the Thames Health Region's programme. Videoconferencing was carried out using a relatively inexpensive personal computer system link using ISDN2 telephone lines and Z350 protocol. Presenter views and assessment were obtained by questionnaire, interview and videotape. Teachers felt that minimal additional preparation time was required for videoconferencing and 21/27 preferred it to in-person teaching, most noting the saving in travel time. Only 3 of the teachers were dissatisfied with their ability to communicate, 4 were equivocal and 20 were either pleased or very pleased. The teachers largely enjoyed the experience and performed well in the new medium. However, sound quality proved inadequate in 5/41 links and most sessions included some periods of suboptimal sound. Only 4 teachers were satisfied with their ability to perform question and answer interaction with the audience. We conclude that experienced teachers adapt readily to videoconferencing and learn to communicate effectively very quickly. Teachers were positive about the medium despite its shortcomings and improvements in sound quality would allow a rapid expansion of postgraduate dental education by videoconference.

Cystic and glial mixed hamartoma of the tongue

Choristomas and mixed hamartomas of the oral cavity are uncommon lesions that show a variety of clinical presentations, histological appearances and growth patterns. We report a case of an unusual mixed hamartoma of the posterior tongue composed of dermoid cyst, sebaceous and glial elements. Magnetic resonance imaging indicated a predominantly cystic lesion limited to the pharyngeal and posterior part of the anterior tongue. A conservative approach was adopted and the lesion has shown minimal growth for 2 years following diagnosis.

Characterization of CD44 splicing patterns in normal keratinocytes, dysplastic and squamous carcinoma cell lines

The CD44 glycoprotein is spliced from a complex gene of 10 constitutive and 10 variant exons. In this study, CD44 splicing patterns and intron 9 retention were investigated by exon-specific RT-PCR for variant exons v1-v10 and intron 9 in normal, immortalized, dysplastic and malignant keratinocytes. Expression of product was determined immunohistochemically for some of the exons. Normal keratinocytes showed one major transcript including exons v2-v10 and 3 minor transcripts. No lines showed a normal CD44 splicing pattern but rather a variety of truncated transcripts of contiguous variant exons which overall correlated with expression. Squamous cell carcinoma (SCC)-4 and SCC-9 lines showed relatively normal transcripts although protein was expressed only by SCC-9. SCC-12B2, SCC-15, SCC-25 and SCC-27 showed a series of shorter overlapping transcripts, with loss of exons v8-v10 in the major transcripts. Intron 9 was not retained in normal keratinocytes or cell lines. Despite the fact that keratinocytes constitutively express all variant exons, splicing patterns are distinctly abnormal and merit investigation as potential markers for epidermal and oral squamous malignancy.

Expression of E-cadherin, cellular differentiation and polarity in epithelial salivary neoplasms

To investigate whether expression of E-cadherin correlates with polarised tissue organisation, grade or tumour type in salivary neoplasms, frozen sections from 30 salivary gland neoplasms were stained immunohistochemically for E-cadherin using the antibody HECD-1 and compared to the staining patterns in five samples of normal salivary gland. Lesions with areas of lack of staining were restained at two higher antibody concentrations. Normal salivary gland stained strongly around the periphery of acinar and ductal cells. Neoplasms mostly stained strongly regardless of neoplasm type. Reproducible loss of expression was found only in epithelial cells showing stromal or plasmacytoid (hyaline) differentiation in pleomorphic adenoma. Low- and high- grade mucoepidermoid carcinomas, adenocarcinoma NOS and carcinoma ex pleomorphic adenoma showed focal loss of expression but this was not related to tissue architecture, differentiation or invasiveness. We conclude that the relationship seen between E-cadherin expression and cell polarity/glandular organisation in breast and colon does not appear to exist for salivary gland neoplasms in which the diversity of architectural patterns precludes detection of any simple relationship. E-cadherin expression seems unlikely to be a useful marker for diagnosis or prognosis in salivary neoplasia in general.

Plasma concentrations of reputed tumor-associated soluble CD44 isoforms (v5 and v6) in smokers are dose related and decline on smoking cessation

There is some evidence to suggest that smoking may affect circulating levels of CD44 (sCD44) molecules. Therefore, we investigated the effect of smoking on the circulating level of sCD44 by comparing the change in total sCD44, sCD44v5, and sCD44v6 concentrations over 1 year in a group of people who quit smoking (n = 30) and a control group of people who continued to smoke (n = 30). Smoking status and compliance were monitored by analysis of plasma cotinine and expired CO levels and also by self-reported tobacco use. We show a dose-dependent relationship between smoke intake and baseline plasma concentrations of reputed tumor-associated CD44 variant isoforms (sCD44v5 and sCD44v6) in smokers (n = 60). There was a significant decline in the level of both sCD44v5 and sCD44v6 in quitters as compared with continuing smokers [-13.2 (95% confidence interval, -7.6 to -18.8; P < 0.001) and -62.2 ng/ml (95% confidence interval, -33.9 to -90.6; P < 0.001), respectively], but not in the total sCD44 concentration. These results show that the increased concentrations of sCD44v5 and sCD44v6 in smokers are dose related and reversible and suggest that the attributed diagnostic specificity and prognostic value of sCD44 molecules in malignant and inflammatory disease may be affected by smoking status.

The acute influence of tobacco smoking on adhesion molecule expression on monocytes and neutrophils and on circulating adhesion molecule levels in vivo

Soluble adhesion molecules have been reported as risk markers of a wide range of human diseases and specific adhesion molecules may play a direct role in pathological processes. Serum soluble intercellular adhesion molecule-1 (sICAM-1) is known to be significantly elevated in smokers compared to non-smokers. We examined the acute effects of smoking a standard 2R1 research cigarette on the serum concentration of sICAM-1 and other circulating adhesion molecules (sP-selectin, sE-selectin, sL-selectin, sVCAM-1 and sPECAM-1) in heavy smokers (serum cotinine >/= 100 ng/ml), light smokers (serum cotinine </= 60 ng/ml) and non-smokers (serum cotinine </= 10 ng/ml) by ELISA. Adhesion molecule expression on the cell surface of monocytes and neutrophils in peripheral blood was examined by flow cytometry. The sICAM-1 concentration directly correlated to serum cotinine concentration (p= 0.047) and nicotine load (p= 0.033) in smokers and was significantly elevated compared to non-smokers (p= 0.037). Other than a decrease in the concentration of sP-selectin over 1 hour regardless of smoking, no significant temporal alterations of any adhesion molecule were observed following the smoking experience or in the non-smoking control group. No significant difference in surface expression of ICAM-1, CD18, PECAM-1 or L-selectin on peripheral monocytes or neutrophils was observed over a 1-hour period following smoking. These data suggest that the elevated concentration of sICAM-1 in smokers is not due to an immediate effect of smoking.

Dental findings in Lowe syndrome

This paper presents the dental findings of a child with the oculocerebrorenal syndrome of Lowe. The genetic abnormality in this condition results in an inborn error of inositol phosphate metabolism. Renal tubular dysfunction leads to metabolic acidosis and phosphaturia. At 4 years, generalised mobility of all primary teeth was noted. It is postulated that a defective inositol phosphate metabolism was responsible for the periodontal pathology found in this case. This is in direct contrast with previous reports of prolonged retention of primary teeth in children with this condition. Histology of extracted primary incisors demonstrated enlarged pulp chambers and mildly dysplastic dentin formation. This is consistent with a chronic subrachitic state, a known feature of Lowe syndrome, but no prominent interglobular dentin was present.

Potential mechanisms of susceptibility to periodontitis in tobacco smokers

Tobacco smoking is probably the most important, controllable environmental risk factor in periodontitis. It results in changes in the vascular, inflammatory, immune and healing responses. The degree of exposure to tobacco smoking can be measured in pack years or by measuring serum cotinine and nicotine levels. In a previous paper we reported elevated levels of serum soluble intercellular adhesion molecule-1 (sICAM-1) in smokers, regardless of periodontal status. Elevated sICAM-1 has been found to be a risk marker for cardiovascular disease. In the present paper we report the short-term effects of an episode of smoking on blood flow and levels of sICAM-1. Human volunteers included non-smokers, light smokers and heavy smokers. Relative blood flow was monitored in the gingivae and forehead skin using a laser Doppler flowmeter and serum levels of sICAM-1, cotinine and nicotine measured before during and up to 60 min following an episode of smoking. We could not provide evidence to support the theory that there is localized vasoconstriction within the gingival tissues. In contrast, there was a significant increase in blood flow in the forehead skin of light smokers which was not observed in non-smoking controls or in heavy smokers, suggesting a long-term tolerance in this latter group. The level of sICAM-1 remained unchanged during this episode, further suggesting a long-term effect. In a parallel group of subjects, we were able to demonstrate a direct significant correlation between sICAM and serum cotinine levels. These observations may be relevant to aetiological mechanisms in periodontitis and other smoking-associated diseases.

Quantitative assessment of apoptosis in oral lichen planus

OBJECTIVE

The aims of this study were to examine the frequency of apoptoses in oral lichen planus by in situ end labeling, to ascertain whether this technique is as sensitive as conventional histologic analysis, and to examine the effect of lymphocytic infiltration.

STUDY DESIGN

Numbers of apoptoses in hematoxylin-eosin stained sections were compared with numbers of apoptotic nuclei identified by in situ end labeling in oral lichen planus (n = 26) and normal buccal epithelium (n = 8). Immunohistochemical staining with MIB-1 and for Bcl-2 and Bax enabled possible regulatory pathways to be investigated.

RESULTS

In oral lichen planus, approximately 1 apoptotic cell was detected per millimeter of basal layer, cell death increasing with lymphocytic infiltration. Epithelial cell proliferation did not correlate with apoptosis. Bcl-2 expression was weak or absent in basal cells, and Bax was localized to upper prickle cells.

CONCLUSIONS

Increased numbers of apoptoses were detected in oral lichen planus, especially in association with lymphocytic infiltration, higher numbers being seen with hematoxylin-eosin staining than with in situ end labeling.

A case of metastasizing pleomorphic adenoma

The pleomorphic adenoma is the most common benign salivary neoplasm. A case is presented in which a palatal pleomorphic adenoma seeded a metastasis in the medullary cavity of the anterior maxilla, apparently by hematogenous spread after surgical manipulation.

Pyostomatitis vegetans associated with asymptomatic ulcerative colitis: a case report

Pyostomatitis vegetans, a rare pustular disorder of the oral mucosa, is a highly specific marker for inflammatory bowel disease and may be difficult to treat. A case of pyostomatitis vegetans in a patient with long-standing asymptomatic ulcerative colitis is presented. Complete remission was achieved with topical steroids; no systemic treatment was required.

A helical region on human lactoferrin. Its role in antibacterial pathogenesis

Human lactoferrin contains a 47 amino acid peptide, named lactoferricin H, which is thought to be responsible for its antimicrobial activity. Lactoferricin includes a loop region, which resides on the outer surface of the N-lobe of lactoferrin, adopting an alpha helix with a hydrophobic tail. Peptides have been synthesised corresponding to the highly charged alpha helix (HLP 2) and hydrophobic tail region (HLP 5). HLP 2 has potent antibacterial activity whereas HLP 5 had no activity. To investigate the relationship between structure and function of HLP 2, HLP 6 was synthesised with a proline replacing methionine. This substitution was predicted to disrupt the helical region of the peptide and the orientation of the positively charged residues. Antibacterial activity was significantly reduced when tested against Escherichia coli serotype 0111, NCTC 8007. The mode of action of HLP 2 against the bacterial membrane was investigated by flow cytometric analysis, using Escherichia coli, NCTC 8007. Membrane potential and integrity were monitored using the fluorescent probes, bis 1,3-(dibutylbarbituric acid) trimethine oxonol and propidium iodide respectively. HLP 2 caused complete loss of membrane potential and integrity, with irreversible damage to the cell as shown by rapid loss of viability. We conclude that HLP 2 causes membrane disruption and that helicity is an important factor for antibacterial activity.

Gingival fibromatosis with prune-belly syndrome

A case is described in which a child appeared for evaluation with marked gingival overgrowth, facial dysmorphism, and abdominal defects consistent with prune-belly syndrome. The relationship between this case and other reports of gingival enlargement are discussed. Coincidence of the oral, facial, and abdominal abnormalities has not been previously reported.

Expression of CD44 variant exons by primary and metastatic oral squamous carcinomas

Abnormal CD44 expression in many neoplasms correlates with behaviour, but reports on its role in oral squamous carcinoma are contradictory. CD44 expression was characterised in a closely matched series of oral carcinomas with and without metastases in both frozen and formalin-fixed tissue and correlated with behaviour and histological grading parameters. Eleven primary oral squamous carcinomas without metastases and nine primary carcinomas with 19 matched metastases were stained immunocytochemically for CD44H and products of variant exons v3, v4/5, v6 and v9. Patterns of staining in frozen and formalin-fixed tissue were correlated with invasive front grading and behaviour using exact inferential statistics. Most primary carcinomas stained for all exons tested but some showed loss of expression of v4/5. Loss of expression was more marked in metastases, but there was no correlation between expression and behaviour or grade. Stromal surfaces of epithelial cells often expressed variant exon products reflecting loss of polarity. This, together with selective loss of v4 and v5 in primary carcinomas and their more frequent loss in metastases, suggests that CD44 may play a role in metastasis of some oral squamous carcinomas.

Structure-function relationship of antibacterial synthetic peptides homologous to a helical surface region on human lactoferrin against Escherichia coli serotype O111

Lactoferricin includes an 11-amino-acid amphipathic alpha-helical region which is exhibited on the outer surface of the amino-terminal lobe of lactoferrin. Synthetic peptides homologous to this region exhibited potent antibacterial activity against a selected range of both gram-negative and gram-positive bacteria. An analog synthesized with methionine substituted for proline at position 26, which is predicted to disrupt the helical region, abolished antibacterial activity against Escherichia coli and considerably reduced antibacterial activity against Staphylococcus aureus and an Acinetobacter strain. The mode of action of human lactoferrin peptide (HLP) 2 against E. coli serotype O111 (NCTC 8007) was established by using flow cytometry, surface plasmon resonance, and transmission electron microscopy. Flow cytometry was used to monitor membrane potential, membrane integrity, and metabolic processes by using the fluorescent probes bis-1,3-(dibutylbarbituric acid)-trimethine oxonol, propidium iodide, and carbonyl cyanide m-chlorophenylhydrazone, respectively. HLP 2 was found to act at the cell membrane, causing complete loss of membrane potential after 10 min and of membrane integrity within 30 min, with irreversible damage to the cell as shown by rapid loss of viability. The number of particles, measured by light scatter on the flow cytometer, dropped significantly, showing that bacterial lysis resulted. The peptide was shown to bind to E. coli O111 lipopolysaccharide by using surface plasmon resonance. Transmission electron microscopy revealed bacterial distortion, with the outer membrane becoming detached from the inner cytoplasmic membrane. We conclude that HLP 2 causes membrane disruption of the outer membrane, resulting in lysis, and that structural considerations are important for antibacterial activity.

Minor salivary gland hyalinisation and amyloidosis in low-grade lymphoma of MALT

Two patients with low-grade lymphoma of mucosa-associated lymphoid tissue (MALT) arising in primary Sjögren's syndrome developed solitary nodules in their lips. Histologically both lesions showed enlargement and hyalinisation of single minor salivary glands with acinar atrophy, loss of most ducts and conversion into almost acellular sclerotic eosinophilic masses. In one case the lesion was shown to contain an amyloid component. No amyloid was detected in the second case but deposition of collagen and basement membrane and sclerotic neoplasm were excluded.

Expression of CD44 variant exons by normal oral epithelia

Altered expression of CD44H an CD44 splice variants is associated with metastasis in several malignancies but its analysis requires knowledge of the normal pattern of expression which is tissue specific. There are considerable regional variations in epithelial differentiation within the mouth, including differences in cell surface glycoproteins. The aim of this study was to determine whether there are regional variations in the expression of CD44 variants in oral epithelia. Frozen and formalin-fixed paraffin-embedded sections of lip vermilion border, buccal mucosa, dorsum and ventrum of tongue, floor of mouth, gingiva and hard palate were stained immunohistochemically for CD44H and the produce of variant exons v3, v4/5, v6 and v9. Paraffin sections were subjected to microwave antigen retrieval. All epithelia stained strongly for all variants in basal, suprabasal and prickle cells and cornified and surface layers and the basal surface of basal cells were negative. Patterns of staining were identical in frozen and formalin-fixed tissue. Despite the structural heterogeneity within oral epithelium, no regional variation was detected.

Hybrid central giant cell granuloma and central odontogenic fibroma-like lesions of the jaws

Ten lesions from eight cases are presented of a rare intra-osseous jaw lesion with the combined histological features of giant cell granuloma and central odontogenic fibroma. Lesions arose over a wide age range and presented as monolocular or multilocular radiolucencies with cortical expansion and, in one case, perforation. Two lesions recurred after curettage, one being eradicated by a second curettage and one by conservative excision. Histologically, zones of typical giant cell granuloma lay in a fibrous stroma containing islands, strands and clusters of epithelial cells. Islands often contained duct-like spaces or hyaline basement membrane globules. Trabeculae of osteoid were present in five lesions. Recurrent lesions showed features identical to the initial lesion, including recurrence of the prominent epithelial component. These features cannot be conclusively ascribed to a variant of either giant cell granuloma, central odontogenic fibroma or aneurysmal bone cyst, but the clinical features are slightly more suggestive of giant cell granuloma. Attention is drawn to the characteristic and potentially confusing histological appearances. The presence of giant cell granuloma-like areas in central odontogenic fibroma-like lesions is associated with an increased risk of recurrence following curettage.

Antibacterial activity of peptides homologous to a loop region in human lactoferrin

Human lactoferrin contains a 46 residue sequence named lactoferricin H thought to be responsible for its antimicrobial properties. Synthetic peptides HLT1, corresponding to the loop region of human lactoferricin (FQWQR-NMRKVRGPPVS) and HLT2, corresponding to its charged portion (FQWQRNMRKVR), exerted significant antibacterial effects against E. coli serotype O111 strains NCTC 8007 and ML35. The corresponding sequences in native human lactoferrin were shown to adopt a charged helix and hydrophobic tail within the N-lobe remote from the iron binding site. Sequence similarities between lactoferricin and dermaseptin and magainins suggest that lactoferricin may act as an amphipathic alpha helix.

B-cell monoclonality in salivary lymphoepithelial lesions

It is well recognised that lymphoma may arise in a lymphoepithelial lesion of the salivary glands. Although the histological features of this lesion are well described, it is not clear what proportion contain monoclonal populations of lymphocytes at outset. In this study, 22 routinely processed lymphoepithelial lesions in parotid glands were examined for B-cell monoclonality using the polymerase chain reaction (PCR) to amplify the immunoglobulin heavy chain gene and using in situ hybridisation or immunohistochemistry to detect kappa or lambda light chain restriction. B-cell monoclonality was identified in 17/22 (77.3%) cases using a combination of the three methods. The detection rate for B-cell monoclonality was highest using PCR with 15/22 (68%) cases containing monoclonal immunoglobulin heavy chain gene rearrangements. In a proportion of cases the results of in situ hybridisation and immunohistochemistry were judged to be inadequate and this was probably a reflection of variations in fixation. In 7 patients, sequential biopsies were available from other sites and 6 of these also showed B-cell monoclonality. The results confirm the high prevalence of B-cell monoclonality in lymphoepithelial lesions of the major salivary glands. Furthermore, these results would suggest that PCR is a more reliable technique to identify B-cell monoclonality in routinely processed lymphoepithelial lesions compared to in situ hybridisation and immunohistochemistry.

p53 immunohistochemistry of odontogenic keratocysts in relation to recurrence, basal-cell budding and basal-cell naevus syndrome

Mutation of the p53 tumour suppressor gene can produce a more stable protein that does not inhibit mitosis, accumulates in the nucleus and can then be detected immunohistochemically in many human tumours using antibody CM-1. The protein has also been detected in odontogenic keratocysts. Routinely processed material from 30 odontogenic keratocysts was immunostained with antibody CM-1. Ten were recurrences and five were associated with the basal-cell naevus syndrome (Gorlin-Goltz syndrome). p53 protein was found in 50% (15/30) of the odontogenic keratocysts, in 53.3% (8/15) of non-recurrent cysts, in 40% (4/10) of recurrent cysts and in 60% (3/5) of those associated with the basal-cell naevus syndrome. Staining was weak and speckled and limited to occasional basal and suprabasal cells. There was no statistically significant difference in staining between these groups and no correlation between expression and the presence of satellite cysts, basal-cell budding or islands of odontogenic epithelium. The low levels of expression may represent physiological expression of wild-type p53 protein rather than mutant or complexed p53 protein.

An unusual intraosseous melanoma in the maxillary alveolus

A case is reported of a 31-year-old white man who presented with a solitary melanoma in the maxillary alveolus. The lesion was located between and had displaced the roots of the lateral incisor and canine and was relatively well circumscribed on radiography. No mucosal origin or potential primary lesion was found, and a marginal excision resulted in the patient remaining free from disease after 7 years of follow-up. Metastasis of melanoma to the jaws is rare even in disseminated disease, and this solitary lesion is unusual. Although metastasis from a regressed primary tumor cannot be excluded, some of the features raise the possibility that this melanoma may have arisen as a primary tumor within bone.

Elastase in gingival crevicular fluid from smokers and non-smokers with chronic inflammatory periodontal disease

OBJECTIVE

To compare elastase concentrations in gingival crevicular fluid (GCF) from individual sites of smokers and non-smokers.

MATERIALS AND METHODS

Twelve pairs of smokers and non-smokers with untreated, moderate to advanced chronic inflammatory periodontal disease were matched for gender, age, ethnicity and the clinical and radiographic extent of disease. Durapore filter strip samples were collected over 30 s from two mesiopalatal sites on upper left posterior teeth. Samples were analysed for: 1) polymorphonuclear neutrophil leucocyte (PMNL) cell counts; 2) PMNL elastase-alpha 1-antitrypsin complex in the GCF supernatant by ELISA; and 3) functional elastase, free or bound to alpha 2-macroglobulin, estimated from activity against N-tert-butoxycarbonyl-alanyl-prolyl-norvalyl-p-chlorothiobenzyl ester in supernatant and lysates of GCF PMNLs.

RESULTS

There were no differences in disease parameters between groups except that bleeding on probing was less extensive in smokers (P<0.001). Cell counts and elastase content of crevicular PMNLs showed no differences between groups. Lower concentrations of elastase were found in GCF supernatants from smokers than non-smokers. This difference was observed for functional elastase (mean [s.d.] = 30.21 [17.60] against 73.77 [75.26] ng microliter(-1), p<0.05) and elastase complexed with alpha 1-antitrypsin (8.97 [6.54] ng microliter(-1) against 25.71 [22.07] ng microliter(-1), p<0.001).

CONCLUSIONS

Smokers have lower elastase concentrations in GCF than non-smokers. Further investigation is required to elucidate the underlying cause and its relationship with periodontal disease.

S100, alpha-smooth muscle actin and cytokeratin 19 immunohistochemistry in odontogenic and soft tissue myxomas

AIMS

To compare the expression of S100 protein, alpha-smooth muscle actin (alpha-SMA) and keratin 19 in odontogenic myxomas and non-odontogenic myxoid lesions.

METHODS

Formalin fixed, paraffin wax embedded tissue from seven odontogenic myxomas, three soft tissue myxomas, six hyperplastic myxoid dental follicles, two intramuscular myxomas, 12 cardiac myxomas, and seven normal dental follicles were examined immunocytochemically for S100 protein, alpha-SMA and cytokeratin 19 using the Streptavidin-biotin method.

RESULTS

A minority of odontogenic myxomas (three of seven) were positive for S100 and the staining was of moderate intensity and in all myxofibroblasts. Soft tissue myxomas, normal dental follicles, intramuscular myxomas, and most enlarged myxoid follicles were negative. In the cardiac myxomas the cells forming cords and islands were positive in approximately half (seven of 12), but the dispersed stellate myxoblasts were positive in only two cases. A population of cells in all the odontogenic myxomas and hyperplastic dental follicles contained alpha-SMA, but such cells were sparse in cardiac myxomas and present in only four cases. Cytokeratin 19 was present in odontogenic epithelium of odontogenic myxoma and follicles.

CONCLUSIONS

A minority of odontogenic myxomas, but not other oral myxoid lesions, may express S100 protein and this could cause difficulty distinguishing myxoma from myxoid nerve sheath tumours. Sparse myofibroblastic cells occurred in all types of myxoma tested. The epithelium sometimes found within jaw myxomas expresses cytokeratin 19 and this is consistent with an odontogenic origin.

The possible association between localized juvenile periodontitis and supernumerary teeth

Supernumerary teeth and localized juvenile periodontitis in the same patient is a very unusual finding. Only 5 cases are reported, 2 of which were identical twins. An additional 2 cases are presented in which localized juvenile periodontitis was associated with multiple supernumerary premolars. These cases are strikingly similar to 3 of the previously reported cases, raising the possibility that this combination of disorders may be more than a chance association.

Oral presentation of minocycline-induced black bone disease

Minocycline hydrochloride is a semisynthetic tetracycline derivative used widely for the treatment of acne vulgaris. Among its side effects is the ability to pigment many tissues particularly thyroid, skin, tooth, and bone. A case is presented in which long-term minocycline therapy (500 g taken orally over 11 years) resulted in dark bone pigmentation (black bone disease) severe enough to be visible through the alveolar and palatal mucosa. No skin or tooth pigmentation was present.

Dental complications associated with repeated orotracheal intubation in infancy: a case report

Various oral and dental problems have been attributed to orotracheal intubation in the neonatal period. A case is described of a child whose dental anomalies are ascribed to multiple orotracheal intubations for the management of a complex cardiac abnormality. Six intubations were required between the ages of 9 days and 4 years for investigation and surgery. His maxillary right primary central incisor did not erupt until 3 years of age and the maxillary left was still unerupted at 6 years and 10 months and was rotated in its crypt. At this time, the mandibular primary incisors were physiologically mobile but the maxillary right primary central incisor remained firm. Both maxillary primary central incisors were extracted and examined histologically and showed abnormal morphology, enamel hypoplasia, and disordered dentine formation and root resorption. Subsequent eruption of the left permanent central incisor revealed hypoplasia of its incisal edge. It is suggested that the delayed eruption and abnormal morphology of the primary incisors were due to pressure effects on the overlying mucosa, follicular displacement and localized trauma caused by intubation. This case highlights the importance of monitoring the developing dentition of patients with a history of orotracheal intubation, so that interceptive treatment may be instituted when appropriate.

The prognostic value of individual histologic grading parameters in small lingual squamous cell carcinomas. The importance of the pattern of invasion

BACKGROUND

The histologic grading of the deep invasive margin of oral squamous cell carcinoma recently has been shown to have prognostic value, but previous series have not been homogeneous enough to allow grading parameters to be assessed individually.

METHODS

Forty-seven small lingual carcinomas limited to the lateral border of the tongue and treated by radiotherapy were graded histologically at their deep invasive front. Clinical and grading parameters were correlated by statistical tests performed by permutational techniques.

RESULTS

Carcinoma recurred locally in 6 patients, and metastases developed in 19. Local recurrence correlated with Broders' grade (P = 0.0143), keratinization (P = 0.017) and pattern of invasion (P = 0.0195). Metastasis had a highly significant correlation with Broders' grade (P < 0.001), pattern of invasion (P < 0.001), and invasive front grading total score (P < 0.001). Seven of 8 carcinomas with diffuse infiltrating patterns metastasised, whereas only 4 of 25 with large islands or a broad infiltrating pattern metastasized.

CONCLUSIONS

The usefulness of the deep invasive front grading system for small lingual carcinoma was demonstrated. The pattern of invasion was the component of the grading system that had the closest correlation with metastasis and recurrence in this type of carcinoma.

Phenotypic characterisation of stellate and giant cells in giant cell fibroma by immunocytochemistry

The origin of the stromal, stellate and multinucleate cells in oral giant cell fibroma is unclear. Sixteen giant cell fibromas were stained immunocytochemically for keratin (MNF 116), vimentin, S-100 protein, neurofilaments, glial fibrillary acidic protein, alpha-smooth muscle actin, desmin, CD31 (PECAM-1), CD68, Factor XIIIa and prolyl 4-hydroxylase (5B5). In all cases positive staining was found with vimentin and prolyl 4-hydroxylase, indicating a functional fibroblast phenotype. Reactivity for Factor XIIIa was seen in two cases and in only one was a small number of giant cells stained, suggesting that the majority of oral giant cell fibromas are unrelated to the histologically similar fibrous papule of the nose or facial angiofibroma.

Symptomatic foreign body reaction to haemostatic alginate

Kaltostat, a haemostatic wound dressing made from non-woven sodium calcium alginate fibres is becoming more frequently and widely used by practitioners. We report a florid foreign body giant cell reaction elicited by Kaltostat which had been used to obtain haemostasis in an apicectomy cavity on an upper lateral incisor approximately 7 months earlier. The case demonstrates that alginate fibres left in situ may elicit a long-lasting and symptomatic adverse foreign body reaction. This material should be reserved for problematic haemorrhage and be removed from the tooth socket soon after haemostasis.

Spindle cell lipoma of the oral cavity: report of a case

A true lipoma is an uncommon lesion intraorally and the spindle cell variant is extremely rare, with only four cases reported in the English language literature. A new case of spindle cell lipoma affecting the tongue of a 68-year old white woman is reported.