Unicystic Ameloblastoma (UA): A Case Series.

Ameloblastomas are true benign tumors of odontogenic epithelial origin mostly seen in the mandible. After odontoma, it is the second most commonly seen odontogenic neoplasm. Ameloblastomas comprise several clinical, radiological, and histological varieties, making them the most significant odontogenic neoplasm. Unicystic ameloblastomas (UAs) refer to those cystic lesions that show clinical, radiographic, or gross features of jaw cysts but on histologic examination, they show a typical ameloblastomatous epithelium lining the cysts' cavities, with or without luminal and/or mural tumor proliferation. UAs are a less encountered variant of ameloblastomas and are believed to be less aggressive. As this tumor shows considerable similarities with dentigerous cysts, both clinically and radiographically the biological behavior of this tumor group was reviewed.

Aneurysmal Bone Cyst Plus Lesions: A Case Report and a Literature Review.

The intraosseous osteolytic lesions mainly involving the metaphyseal region of vertebrae and long bones were diagnosed as aneurysmal bone cysts (ABCs). Further, an ABC was known as an ossifying hematoma. It is considered an expanding osteolytic lesion consisting of blood-filled spaces of variable sizes separated by connective tissue septa containing trabeculae of osteoid tissue and osteoclast giant cells. It is frequently reported to involve long bones; however, only 1.9% prevalence is seen in jaw bones. It represents a very small percentage of all non-odontogenic tumors. ABC shows variations in age prevalence and its clinical presentation may be challenging to the surgeon. In addition, ABC may occur in association with other primary bone pathologies like ossifying fibroma, fibrous dysplasia, and giant cell tumor; such entities are known as ABC plus lesions. Here we present a classic case of ABC plus lesion.

Significance of HIF-1α and CD105 in establishing oral squamous cell carcinoma associated with oral submucous fibrosis a distinct clinicopathological entity.

Context: Oral squamous cell carcinoma associated with oral submucous fibrosis (OSCC with OSMF) is clinicopathologically a distinct entity. However, scientific proof in view of assessment of biomarkers of hypoxia and neoangiogenesis to differentiate them are lacking. The expression of hypoxia-inducible factor 1-α (HIF-1α) and CD105 in OSCC with and without OSMF possibly will be explicated along these lines. Aim: This study aims to evaluate the molecular basis of hypoxia and neoangiogenesis in terms of immunohistochemical expression of HIF-1α and CD105 in OSCC with and without OSMF cases. Settings and Design: A retrospective cohort. Subjects and Methods: The study comprise of 203 histopathologically diagnosed surgically operated cases of OSCC retrieved from the departmental archives. The OSCC cases were subgrouped into two, OSCC with OSMF (Group I) and OSCC without OSMF (Group II). The evaluation of hypoxia and angiogenesis was carried out by immunohistochemical markers, HIF-1α and CD105. MVD is the parameter of angiogenesis expressed by CD105. Statistical Analysis Used: Differences in CD105, and HIF-1α immunoreactivity between study groups were done using descriptive statistics using "Kruskal-Wallis test," "Mann-Whitney test." Statistical significance was set at P < 0.05. Results: On comparison of MVD in Group I and II, statistically significant difference was found in MVD (8.88 ± 3.41, 16.13 ± 5.86, P = 0.0001). The HIF1-α expression was less in Group I (6.85 ± 2.62) as compare to Group II (7.22 ± 3.08) but the difference was statistically nonsignificant (P = 0.35). Conclusions: The OSCC with OSMF is not only clinicopathologically distinct entity of OSCC but also diverse in its molecular pathogenesis as explicited by distinct expression of HIF-1 α and CD105.

Oral submucous fibrosis: An enigmatic morpho-insight.

Oral submucous fibrosis (OSMF) is a chronic progressive, scarring disease affecting oral, oropharyngeal, and sometimes the esophageal mucosa. It is characterized by the progressive fibrosis of the submucosal tissue. The pathogenesis of OSMF has been directly related to the habit of chewing areca nut and its commercial preparation, which is widespread in Indian subcontinent and Southeast Asia. The areca nut has been classified as a "group one human carcinogen." Oral squamous cell carcinoma in the background of OSMF is one of the most common malignancies in South and Southeast Asian countries. Malignant transformation has been reported in 7%-12% cases of OSMF. Histopathological spectrum of OSMF includes the apparent alterations observed in the epithelium and connective tissue. Epithelial atrophy and sometimes epithelial hyperplasia with or without dysplasia are the peculiar alterations seen in the epithelium. In the connective tissue, there is extracellular matrix remodeling which results in excessive collagenization. Further cross-linking of collagen leads to hyalinization which makes the collagen resistant to proteolysis. Owing to fibrosis in the connective tissue, there is narrowing of blood vessels which further results in compromised blood supply to the local tissue milieu, that is, hypoxia. This tissue hypoxia elicits angiogenesis which may result in the malignant transformation of OSMF. Perpetual irritation of areca nut and its constituents to the oral mucosa leads to upregulation of pro-inflammatory cytokines and further juxtaepithelial inflammation. Thus, these coordinated reactions in epithelium and connective tissue leads the OSMF toward malignant transformation.

Impact of virtual microscopy with conventional microscopy on student learning in dental histology.

BACKGROUND: In dental histology, the assimilation of histological features of different dental hard and soft tissues is done by conventional microscopy. This traditional method of learning prevents the students from screening the entire slide and change of magnification. To address these drawbacks, modification in conventional microscopy has evolved and become motivation for changing the learning tool. Virtual microscopy is the technique in which there is complete digitization of the microscopic glass slide, which can be analyzed on a computer. This research is designed to evaluate the effectiveness of virtual microscopy with conventional microscopy on student learning in dental histology. MATERIALS AND METHODS: A cohort of 105 students were included and randomized into three groups: A, B, and C. Group A students studied the microscopic features of oral histologic lesions by conventional microscopy, Group B by virtual microscopy, and Group C by both conventional and virtual microscopy. The students' understanding of the subject was evaluated by a prepared questionnaire. RESULTS: The effectiveness of the study designs on knowledge gains and satisfaction levels was assessed by statistical assessment of differences in mean test scores. The difference in score between Groups A, B, and C at pre- and post-test was highly significant. This enhanced understanding of the subject may be due to benefits of using virtual microscopy in teaching histology. CONCLUSION: The augmentation of conventional microscopy with virtual microscopy shows enhancement of the understanding of the subject as compared to the use of conventional microscopy and virtual microscopy alone.

Tumor angiogenesis: role in locally aggressive biological behavior of ameloblastoma and keratocystic odontogenic tumor.

BACKGROUND: The purpose of this study was to assess and compare angiogenesis in ameloblastoma, keratocystic odontogenic tumors, dentigerous cysts, and normal oral mucosa. METHODS: Angiogenesis was assessed in 28 ameloblastoma-36 keratocystic odontogenic tumors, 28 dentigerous cysts, and 19 normal oral mucosa by measuring the mean vascular density (MVD), total vascular area (TVA) and mean vascular area (MVA). Immunohistochemistry was carried out by using CD105. RESULTS: The nonsignificant difference of MVD was noted between ameloblastoma and keratocystic odontogenic tumors (p = .174). TVA and MVA were significantly higher in ameloblastoma than keratocystic odontogenic tumors, normal oral mucosa, and dentigerous cysts (p < .001). MVD, TVA, and MVA were significantly higher in keratocystic odontogenic tumors than normal oral mucosa and dentigerous cysts (p < .001). CONCLUSION: The results suggest that tumor angiogenesis may play an important role in locally invasive aggressive biologic behavior of ameloblastoma and keratocystic odontogenic tumor. The angiogenesis could be a potent target for developing antiangiogenic therapeutic strategies, particularly in recurrent cases of odontogenic tumors.

Correlation between mucoepidermoid carcinoma grade and AgNOR count.

Mucoepidermoid carcinoma (MEC) is a malignant glandular epithelial neoplasm having an unpredictable behavior and a tendency to recur. Numerous parameters have been assessed to predict the outcome of this lesion, but have been deemed inadequate, with the exception of tumor stage and grade. In the present study, we attempted to correlate the proliferative activity of MEC with its histopathological grade, using argyrophillic nuclear organizer region (AgNOR) count. Thirty cases of MEC were included in the study. All the slides were stained using hematoxylin and eosin and silver nitrate techniques. Counting was performed at a magnification of x1,000 with an oil-immersion lens. Positive correlations were seen between AgNOR count and MEC grade (P < 0.05), with AgNOR count increasing in proportion with tumor grade. The AgNOR count in various grades of MEC indicates a relative progression in the proliferative activity of this tumor. This index is positively correlated with tumor grade, although there are some exceptions. The utility of AgNOR count in predicting the prognosis of MEC can be considered of importance; however, further assessment, such as survival studies, is necessary.