Grading of Oral Leukoplakia: Can It be Improvised Using Immunohistochemical Markers p63 and CD31.

INTRODUCTION: Oral squamous cell carcinoma is usually preceded by potentially malignant disorders (PMDs), the most common being oral leukoplakia. A conservative management protocol is followed for milder dysplastic cases, while severe dysplastic lesions are surgically excised. Several classification systems have been developed based mainly on histopathological features with a lot of inter-observer variations. The present study was done to assess the use of immunohistochemical (IHC) markers in grading leukoplakic lesions in addition to histopathological grading. AIMS AND OBJECTIVES: To grade leukoplakia using different grading systems and assess if IHC markers can aid in categorizing leukoplakia. MATERIALS AND METHODS: Thirty-five cases of leukoplakia were graded using Ljubljana, 2005 World Health Organization (WHO), and Binary System followed by IHC staining with p63 and CD31. RESULTS AND STATISTICS: Variation was noted in 12 cases while using WHO, 11 using Ljubljana, and 7 using Binary System and was significant on Cohen-Kappa statistics, with the least significant variation noted on Binary System. p63 staining assisted to group doubtful cases and even identify variation in cases graded positively on histopathology. In total, 17 cases stained one-third (mild/low), while 15 cases stained one-half or more (higher grade) epithelial thickness. A weak correlation was observed between all grading systems and p63 on Kendall's Tau-b analysis and the weak correlation was significant for the WHO and binary grading systems. Analyzing p63 and CD31 using Kruskal-Wallis test, an increase in mean vessel density (MVD) was noted for mild/moderate cases but decreased for severe cases. CONCLUSION: Addressing histological categorization of PMDs assisted by IHC markers to understand the biological behavior of the tissues is currently essential with studies on more markers to assist in the management protocol.

Characterization of perineural invasion in different histological grades and variants of oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) accounts for 3% of all malignant neoplasms and is the fifth most frequent cancer in the world. They usually spread by hematogenous or lymphatic spread, and perineural invasion (PNI) is considered an alternate method of tumor spread where it is described as the tumor affinity toward a neural tissue. AIM AND OBJECTIVES: The present study aims to evaluate the biological behavior of OSCC with respect to PNI and to evaluate the importance of PNI with respect to different histopathological grades and variants, tumor stage and lymph node status of OSCC. PNI was also assessed with respect to its frequency, patterns, types and number in various grades of OSCC. MATERIALS AND METHODS: This retrospective, double-blind study was conducted on 148 histopathologically proven cases of different histopathological grades and variants of OSCC. The tissue sections were examined for PNI and its patterns and were further compared with habit history, site of the lesion, tumor staging, grading and lymph node status. RESULTS: A Chi-square test was performed. A percentage positivity of 45.27% (67 cases) among 148 cases was found. PNI positivity of 63.6% and 50% was observed in T4 and T3 tumor stages, respectively, with high significance. Seventy percent of cases belonging to poorly differentiated squamous cell carcinoma showed positivity for PNI, which was statistically significant. PNI positivity with respect to lymph node status is nonsignificant. CONCLUSION: The present study showed that there is a direct proportionality between PNI and different grades and stages of OSCC. Given this context, a histopathologist ought to examine for PNI and make it mandatory to report the same to the clinician for better treatment and follow-up of the patient.

The synergy of tobacco and alcohol and glutathione S-transferase θ 1 gene deletion and oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is the leading cancer among males in India. It is related to tobacco habits and alcohol consumption as well as the individual susceptibility for xenobiotic metabolizing enzyme polymorphisms. Glutathione S-transferase θ 1 (GSTT1) is a Phase II metabolic enzyme which is directly involved in catalyzing chemicals to mutagenic intermediates. This gene is characterized by genetic polymorphism resulting in complete gene deletion and subsequent absence of the enzyme, which ultimately dictates the risk of cancer development. Scraping buccal mucosa to obtain DNA from the cells is a simple, readily acceptable and rapid method to detect and assess the gene. AIM: To assess GSTT1 gene deletion in individuals giving a history of tobacco smoking and/or chewing and alcohol consumption and absence of clinically detectable lesions; and in OSCC cases to gauge if GSTT1 gene deletion confers protection to an individual and whether it can be used as a "single" marker to arrive at this conclusion. To validate the use of buccal scrape for determining the genotype of an individual by assessing the polymorphism at GSTT1 gene locus (22q11.2). MATERIALS AND METHODS: Fifty-two cases were evaluated using buccal mucosal scrapes of tobacco habituates for 8 or more years, without clinically evident lesion (Group I) and from mucosa of tobacco habituates with clinically evident and histopathologically confirmed OSCC (Group II). DNA extraction and genotype at GSTT1 gene locus was determined by polymerase chain reaction assay. STATISTICAL ANALYSIS: The results were statistically analyzed using Chi-square test. RESULTS: 90.66% of subjects had GSTT1 null genotype in Group I subjects. In Group II, subjects with both clinically and histopathologically diagnosed oral cancer, about 76.96% had GSTT1 null genotype. CONCLUSION: GSTT1 null genotype confers protection to individuals with tobacco habits and alcohol consumption, predominantly to those who used chewable form of tobacco and especially among female population. However, the influence of many other environmental, genetic and epigenetic factors should be considered for the genesis/occurrence of cancer.

Quantification of Porphyromonas gingivalis in chronic periodontitis patients associated with diabetes mellitus using real-time polymerase chain reaction.

INTRODUCTION: Periodontal diseases, if left untreated, can lead to tooth loss and affect at least one tooth in 80% of adults worldwide, with the main cause being a bacterial plaque. Among subgingival plaque bacterial species, Porphyromonas gingivalis has been implicated as a major etiological agent causing tooth loss. Diabetics and smokers are two patient groups at high risk for periodontal disease. The increase in the number of this organism with the coexistence of other pathogenic microbes leads to rapid destruction of the periodontium, premature loss of teeth and also because of its virulence has implications in systemic pathology. Our aim was to observe the involvement of P. gingivalis in diabetes mellitus (DM) patients associated with periodontitis with and without tobacco-associated habits and to compare them with periodontitis patients having no other systemic pathologies. MATERIALS AND METHODS: Subgingival plaque samples from a total of seventy subjects were included in the study. DNA was isolated from the collected sample and was quantified using spectrophotometer for standardizing the polymerase chain reaction. The quantity of the isolated DNA was checked in a ultraviolet-visible spectrophotomer. STATISTICS: One-way ANOVA and Tukey's multiple post hoc procedures were carried out. RESULTS: The maximum score of P. gingivalis was seen in periodontitis patients having DM, whereas the least score was seen in periodontitis patients having DM with tobacco smoking habit compared to the other groups. CONCLUSION: P. gingivalis count is significantly reduced in periodontitis patients having DM with smoking habit; it is concluded that P. gingivalis might not be a key causative organism responsible for the periodontal destruction in case of smokers despite the DM condition. The decrease in counts may be attributed to change in the local environment like chemical (tobacco nitrosamines) and physical changes preventing the growth of P. gingivalis.

Survivin expression in oral lichen planus: Role in malignant transformation.

CONTEXT: Oral lichen planus (OLP) is a potentially malignant disease with a prevalence rate of 0.5-2.2%. It is a T-cell-mediated autoimmune disease, in which cytotoxic CD8+ T-cells trigger apoptosis of the basal cells of oral epithelium. The reported progression of OLP to oral squamous cell carcinoma (OSCC) ranges from 0.4% to 6.5%. Apoptosis plays a major role in the maintenance of tissue homeostasis. The evasion of apoptosis in the form of dysregulation of inhibitors of apoptosis proteins (IAPs) may lead to malignant transformation. Survivin belongs to the second gene family of IAPs, which is overexpressed in many tumors such as OSCC and gastric carcinomas, and its expression is widely involved in apoptosis as well as in tumor metastasis. MATERIALS AND METHODS: Sections were obtained from the paraffin-embedded archival blocks of patients diagnosed histologically as OLP, and cases with normal epithelium were used for comparison whereas cases with OSCC were used as positive control. RESULTS: We analyzed the expression of survivin in OLP and normal epithelium. Survivin expression with moderate intensity was seen in the cells of basal layer with nuclear positivity in cases of OLP, whereas mild to nil expression was seen in normal epithelium with nuclear and cytoplasmic positivity in different layers. CONCLUSIONS: Survivin positivity was seen predominantly in the basal cells of OLP suggesting increased longevity of these cells which in turn might acquire dysplastic changes leading to increased risk of malignant transformation of this premalignant condition. Although the conversion rate may be low, the potential exists in the indolent course of the disease.

Adjunctive role of dental restorations in personal identification of burnt victims.

BACKGROUND: Fire remains one of the major causes of morbidity and mortality throughout the world and identification of a body from the fatal fire remains a daunting task. Several forensic cases involve interpretation of burnt human bodies from airline and automobile accidents, bombings and unlawful cremation. Fire is also involved in homicides, suicides, accidental death, arson and in attempts to destroy forensic evidence in criminal cases. Soft tissue destruction from fire can be so extensive that conventional methods of identification may be impossible. However, teeth survive even high temperatures due to their resistant composition and so, obviously, the restorative material housed in the teeth are even more secure and can yield valuable information in personal identification. AIM: To assess the usefulness of most common restorations in personal identification in burnt cases. MATERIALS AND METHODS: The study was conducted on 40 extracted teeth which were divided into four groups (Group 1 - Unrestored teeth, Group 2 - Amalgam restored, Group 3 - Glass ionomer restored and Group 4 - Composite resin restored teeth. The effect of incineration at 200°C, 400°C, 600°C, 800°C, 1000°C for 15 min at each target temperature followed by subsequent cooling was studied. RESULTS: Amalgam restoration was resistant and intact even at 1000°C, whereas GIC and composite restoration are identifiable till 600°C, the residual cavity preparation leaves a clue for narrowing down the spectrum of identification.

A phase contrast cytomorphometric study of squames of normal oral mucosa and oral leukoplakia: Original study.

UNLABELLED: Oral leukoplakia represents the most common potentially malignant oral disorder, representing 85% of such lesions. The worldwide prevalence of leukoplakia is 1.5- 4.3%. Leukoplakia is often associated with carcinogenic exposures, such as from use of tobacco, alcohol or betel nut. The level of risk for malignant transformation of leukoplakia is associated with lesion histology. The overall malignant transformation rates for dysplastic lesions range from 11% to 36%, depending on the length of follow-up. Exfoliative cytology is a simple and minimally invasive method. Phase contrast microscope, an essential tool in the field of biology and medical research provides improved discrimination of cellular details. AIMS: To study and compare the cytomorphological and cytomorphometric features of squames obtained from the mucosa of normal individuals, tobacco habituates with and without clinically evident leukoplakia. To assess the role of phase contrast microscopy as an alternative and easy method of cytological evaluation of wet and unstained smears. MATERIALS AND METHODS: Fifty cases from each group were taken. Fixed, unstained smears were viewed under phase contrast microscope and were evaluated morphologically and morphometrically for nuclear and cellular diameters. RESULTS: The study showed a significant increase in the mean nuclear diameter and decrease in the mean cellular diameter. CONCLUSION: Cytomorphometric changes could be the earliest indicators of cellular alterations. This indicates that there could be a cause-effect relationship between tobacco and quantitative alterations.

Expression of Ki-67 in normal oral epithelium, leukoplakic oral epithelium and oral squamous cell carcinoma.

AIMS AND OBJECTIVE: To demonstrate the presence, location and pattern of cell proliferation in different histological grades of oral epithelial dysplasia (OED), oral squamous cell carcinoma (OSCC) and normal oral epithelium (NOE) using an antibody directed against the Ki-67 antigen and its intensity of staining evaluated respectively. MATERIALS AND METHODS: A total number of 100 archival paraffin embedded blocks obtained from Department of Oral and Maxillofacial Pathology were studied. The case details were retrieved which consisted of histopathologically diagnosed cases of OSCC (n = 20), low risk OED (n = 30), high risk OED (n = 30) and normal appearing mucosa (n = 20) were taken as standard for comparison. Ki-67 immunostaining was detected. Ki-67 positive cells were counted in the five random high power fields in each case. RESULTS: Ki-67 labeling Index (LI) was restricted to the basal and parabasal layers of the normal oral epithelium irrespective of age, sex and site whereas it was seen in the basal, suprabasal and spinous layers in OED. Ki-67 LI is increased in high risk cases than the low risk cases of OED. Ki-67 positive cells in OSCC were located in the periphery of the tumor nests than the center, where frequent mitoses were observed. CONCLUSION: The architectural alteration evaluated by Ki-67 antibody in proliferating cell distribution in the layers of epithelial dysplasias may provide useful information to evaluate the grading of OED. Ki-67 LI increased in high risk cases than low risk cases of OED. This study showed that over expression of Ki-67 antigen between well-differentiated and poorly differentiated OSCC was in accordance with histologic grade of malignancy but not in accordance with moderately differentiated OSCC.

Chondromyxoid fibroma of zygoma: A rare case report.

Chondromyxoid fibroma (CMF) is a rare benign mesenchymal tumor of the bone. Clinically, it is characterized by a lobular growth pattern and histologically by chondroid and myxoid differentiation. The tumor is rare in the craniofacial bones with only 2% of all reported cases. Extragnathic location in the facial skeleton is extremely rare. Most of the cases reported either originate from gnathic sites or in the cranium. A case of CMF in a 3½-year-old male is presented here, which arose from the root of zygomatic arch. A detailed clinical history and histopathological picture of one more case is added to the literature. It is important to document such cases so that better light can be shed on future reviews and conclusions. This shall facilitate better treatment approaches and prognosis. This case is the first reported case of involvement of the zygomatic arch in a pediatric patient.

Monostostic fibrous dysplasia with nonspecific cystic degeneration: A case report and review of literature.

Fibrous dysplasia (FD) has been regarded as a developmental skeletal disorder characterized by replacement of normal bone with benign cellular fibrous connective tissue. It has now become evident that FD is a genetic disease caused by somatic activating mutation of the Gsα subunit of G protein-coupled receptor. Here we report a case of bilateral monostotic FD in a middle-aged female showing a classic histological picture, but radiologically presenting as a mixed radiolucent radiopaque lesion showing nonspecific cystic degeneration.

Clear cell unicystic ameloblastoma.

Clear cell differentiation in unicystic ameloblastoma with inclusion of many other histologic variants in the same tumor is a very rare occurrence. Here, we report a case of a well-circumscribed large mandibular swelling in a 22 - year old female. The lesion was histopathologically diagnosed as unicystic ameloblastoma which showed multiple histologic patterns and clear cell differentiation. The tumor was treated with surgical enucleation and chemical cauterization. A follow up of 20 months has shown no recurrence after initial surgery.

Myxoglobulosis of lower lip: Report of two cases.

In this paper, we present two case reports of myxoglobulosis, in a 24-year-old female and a 40-year-old male patient who came to our hospital with a chief complaint of painless swelling of the lower lip of approximately 6 months duration. A study of two case reports has been given here. In these patients, histological examination of the surgically excised tissue was carried out. Histopathological examination showed an extravasation mucocele with the lumen exhibiting unique globular organizations of mucin surrounded by granulation tissue capsule and lacking an epithelial lining. Our two cases are possibly an analogue of myxoglobulosis, a rare variant of the appendical mucocele. Thus, though rare, the possibility of occurrence of myxoglobulosis in cystic lesions of the lip should be considered. The prognosis is regarded better as compared to the other types of mucoceles with low recurrence rate due to good host response and globular organizations of mucin. However, follow- up of these cases and more such cases is required to confirm the prognosis. The need for study of many such cases to confirm the etiology, pathogenesis and biologic nature of this variant is being felt.