Granular cell ameloblastoma: A rare case report and review of literature.

Ameloblastoma is a benign locally aggressive type of odontogenic tumor derived exclusively from the epithelium. Histologically, ameloblastoma is classified into many variants, of which granular cell ameloblastoma (GCA) is a rare type, characterized by nest of large eosinophilic granular cells. This article describes a case of GCA in a 50-year-old female patient with clinical, radiological, and histological features along with a systematic review of the literature.

ESEM Detection of Foreign Metallic Particles inside Ameloblastomatous Cells.

Ameloblastoma is a borderline tumor of odontogenic origin, with a high recurrence rate and possible local aggressiveness. The etiopathogenetic factors involved in its occurrence are not still defined and our study has been precisely aimed to search for novel factors associated with its development. Sections cut from paraffin blocks, containing the representative specimens of 18 different ameloblastomas, collected in a 15-year period (1999-2014), have been observed by an environmental scanning electron microscope, in order to search micro- and nano-sized particles and to identify their composition. In all the neoplastic cases, micro- and nano-sized metallic debris, differing in size and composition, have been detected inside the ameloblastomatous cells. On the contrary, the total absence of metallic particles in the healthy control cases has been emerged. Our results reveal a relationship between ameloblastoma and metallic particulate. The cigarette smoke and the routine dental practice appear the most probable source for the presence of these biopersistant inorganic particles inside the neoplastic cells.

Ghost cells in pilomatrixoma, craniopharyngioma, and calcifying cystic odontogenic tumor: histological, immunohistochemical, and ultrastructural study.

BACKGROUND: Pilomatrixoma, craniopharyngioma, and calcifying cystic odontogenic tumor are the main entities presenting ghost cells as an important histological feature, in spite their quite different clinical presentation; it seems that they share a common pathway in the formation of these cells. The aim of this study is to examine and compare the characteristics of ghost and other cells that form these lesions. METHODS: Forty-three cases including 21 pilomatrixomas, 14 craniopharyngiomas, and eight calcifying cystic odontogenic tumors were evaluated by immunohistochemistry for cytokeratins, CD138, ß-catenin, D2-40, Glut-1, FAS, CD10 and also by scanning electron microscopy. RESULTS: The CKs, CD138, ß-catenin, Glut-1, FAS, and CD10 were more often expressed by transitional cells of craniopharyngioma and calcifying cystic odontogenic tumor, compared with pilomatrixoma. Basaloid cells of pilomatrixoma showed strong positivity for CD138 and CD10. Differences on expression pattern were identified in transitional and basal cells, as ghost cells were negative for most antibodies used, except by low expression for cytokeratins. By scanning electron microscopy, the morphology of ghost cells were similar in their fibrillar cytoplasm, but their pattern varied from sheets in pilomatrixoma to small clusters in craniopharyngioma and calcifying cystic odontogenic tumor. CONCLUSIONS: Mechanisms involved in formation of ghost cells are unknown, but probably they follow different pathways as protein expression in the basal/transitional cells was not uniform in the three tumors studied.

Quantitative and qualitative analysis of argyrophilic nuclear organizer regions in follicular cyst, keratocystic odontogenic tumor and ameloblastoma.

BACKGROUND: Multicystic ameloblastoma is a benign odontogenic tumor that exhibits a more aggressive behavior than keratocystic odontogenic tumor (KCOT) and follicular cyst. AIM: The purpose of the study was to evaluate the proliferation index nuclear organizer regions (NORs) and their distribution among the four odontogenic lesions with known different clinical invasive behavior. STUDY AND DESIGN: In a descriptive-analytical cross-sectional study, 60 paraffin blocks of odontogenic lesions were prepared for silver nitrate staining. MATERIALS AND METHODS: For the quantitative analysis, 100 cells were counted at ×100 and the mean value was calculated. The morphometric analysis of NORs showed that they can be distributed into normal (round to oval-shaped) and abnormal (large, bean-shaped and cluster-shaped) groups. One-way analysis of variance (ANOVA) and multiple comparison with Tukey test were used for the statistical analysis of the results. RESULTS: The argyrophilic NOR (AgNOR) numbers in multicystic ameloblastoma, unicystic ameloblastoma, KCOT, and follicular cyst were 7.4 ± 2.7, 6.1 ± 2.56, 4.7 ± 1.84, and 2.82 ± 1.052, respectively. The difference between ameloblastoma (unicystic and multicystic types) and either_KCOT, or follicular cyst was statistically significant (P<0.001) and, (P=0.001), respectively. In follicular cysts, normal AgNOR dots were not detected outside the nuclei. NOR histological patterns of KCOT were large, bean shaped and rarely cluster shaped and it was cluster-shaped in multicystic and unicystic ameloblastoma. CONCLUSION: The current study suggests that determination of clinical behavior of ameloblastoma in comparison with KCOT and follicular cyst in silver nitrate staining is related to higher proliferation activity and different NORs' distribution pattern. However, further clinical follow-up studies must be performed to prove this.

An image processing software applied to oral pathology.

This study presents the development and evaluation of an image processing software for computer-assisted cellular structure counting. The proposed software consists of a set of processing and analytical tools which allows its use in several applications of cell and cellular structure counting. A particular application in AgNOR quantitative analysis is presented. The knowledge obtained from experienced pathologists has been codified in a sequence of processing steps in order to allow automatic estimation of the mean number of AgNORs per cell in ameloblastomas. The performance of the presented software in such application was verified by comparing the data provided by visual analysis, by two observers previously calibrated and under supervision of two experienced specialists (Group 1) and by the computer program (Group 2). No statistical difference was observed (p<0.05) between the two groups. The use of the proposed method in AgNOR applications permitted attainment of accurate and precise data without the difficulties frequently found in the traditional visual analysis method (time, training and subjectivity). The developed software is an interesting tool as an aid in the study (estimation of the number of cells and cellular structures) of malignant and benign neoplasms.

Odontoma: retrospective study and confocal laser scanning microscope analysis of 52 cases.

AIM: The aim of this study was to perform a retrospective analysis of 52 cases of odontoma treated at the Department of Dentistry and Surgery, University of Bari, in the period 1971-2005. METHODS: The odontogenic tumors were diagnosed as complex or compound odontoma following histological analysis and clinical radiological examination, and applying the 2005 WHO classification. The data analysis was conducted by considering the following factors: gender, age, site of the lesion, association with impacted teeth, aplasia, presence of supernumerary teeth as well as preoperative diagnosis by panoramic and periapical radiographs. Biopsy tissue samples were conventionally processed for histopathologic paraffin embedding and then were observed by optical microscopy and subsequently by confocal laser scanning microscopy (CLSM) in autofluorescence. RESULTS: Thirty specimens (57.6%) were from females and 22 (42.3%) were from males patients. The patients' age ranged from 5 to 75 years. Fifty-one percent of the specimens were excised from the mandible. In the maxilla, the most common location for odontomas was the anterior region. Most odontomas were associated with impacted teeth and only in one case there was an odontoma instead of a permanent tooth. CONCLUSION: Odontomas are considered hamartomatous malformations whose diagnosis is generally formulated by routinary radiographic examination. The CLSM analysis could help in diagnosis and histopathological analysis showing well-defined follicular area entrapped in hard tissues and pointing out ghost cells, otherwise not identifiable by traditional microscopy.

Ultrastructural studies of jaw lymphomas and apoptosis.

Research on ultrastructural cytopathological changes and apoptosis that occur in jaw lymphoma were done by using electron microscopy and ground sections. The author described this tumor in 1977-1978 as a highly malignant and lethal condition affecting children between 2 and 8 years (mean age 5 years). A duration of illness between 2 and 3 weeks is common and with a general condition of severe toxicity, anemia, and high body temperature. Clinical and pathological features of 24 children with jaw lymphoma seen in the Maxillofacial Unit, Surgical Specialized Hospital, Medical city, Baghdad, are described. Thirteen males and 11 females were included, with a death rate at 91.1%. The morphological characteristics were examined by ground sections. Lymphoblastic lymphoma features were observed and apoptotic changes were seen in some of the cells. Electron microscopy showed a high number of mitotic figures and lymphoblast transformation to plasma cells with high nucleo-cytoplasmic ratio. Some cells had double nuclei and some nuclei were more convoluted. Apoptotic changes were seen in some cells; chromatin clumps aggregated near the nuclear membrane. Cytoplasmic processes and mitochondria showing degeneration and virus-like particles were seen in both nuclei and cytoplasm. The presence of a high mitotic figure with active oncogenic virus growth and reduced apoptosis is a poor prognostic feature in jaw lymphoma.

Analysis of ghost cells in calcifying cystic odontogenic tumors by confocal laser scanning microscopy.

OBJECTIVE: The confocal laser scanning microscope represents an effective tool for studying biological samples stained for fluorescence observation. In this study we have used the confocal microscope to analyze ghost cells in calcifying cystic odontogenic tumors. STUDY DESIGN: Specimens from 15 calcifying cystic odontogenic tumor cases were stained with hematoxylin and eosin, and scanned by a confocal laser scanning microscope to generate optically sectioned images. RESULTS: All of the analyzed samples presented autofluorescent cells that were identified as ghost cells. The degree of autofluorescence intensity was variable and may be a result of the presence of hard keratin. CONCLUSION: The confocal laser scanning microscope may be of help in analyzing and defining the nature and extent of keratinization processes in calcifying cystic odontogenic tumor ghost cells.

Spindle-cell ameloblastic carcinoma: A case report with immunohistochemical, ultrastructural, and comparative genomic hybridization analyses.

Spindle-cell ameloblastic carcinoma is a classification proposed for a group of rare odontogenic carcinomas with sarcomatoid components and is distinguished from odontogenic carcinosarcoma. We report a case of spindle-cell ameloblastic carcinoma of the right mandible that occurred in a 67-year-old Japanese man. Growth of the tumor was destructive, there was extensive lung metastasis, and the outcome was unfavorable. Ultrastructural and immunohistochemical examination showed the spindle-cell component of the tumor to be epithelial in character. A gain of 5q with amplification of 5q13 was detected in the tumor by comparative genomic hybridization.

Immunohistochemical localization of large chondroitin sulfate proteoglycan in odontogenic tumor.

The present study investigated the localization of versican in odontogenic tumors by immunohistochemistry, using paraffin-embedded sections obtained from 27 patients with odontogenic tumors (17 ameloblastomas, 1 adenomatoid odontogenic tumor, 4 odontogenic keratocysts, 1 calcifying odontogenic cyst, 2 ameloblastic fibromas, and 2 malignant ameloblastomas). Deparaffinized sections were immersed in a buffered 1 : 1000 solution of an antibody, 5D5 (raised against a large chondroitin sulfate proteoglycan from bovine sclera), which mainly recognizes versican. All samples showed a positive reaction for versican in connective tissues, whereas positive staining of epithelial nests was observed in only some samples. The positive staining in epithelial nests was in areas showing stellate reticulum-like, cuboidal, columnar cells at the periphery, and tear-drop structures. These results indicated that versican might be involved in, at least in part, the morphogenesis of neoplastic epithelium and mesenchymal tissues in odontogenic tumors.

[Ameloblastic fibrosarcoma: an immunohistochemical and ultrastructural study of the mesenchymal component].

To study the characteristics of the mesenchymal cells of ameloblastic fibrosarcoma (AFS), three cases of AFS were studied immunohistochemically and ultrastructurally. The results showed that the mesenchymal component of AFS consisted predominantly of fibroblastic cells with a small number of undifferentiated cells, a few histiocytes and occasionally myofibroblastic cells under electron microscope. The fibroblastic cells were Vimentin positive only, and myofibroblastic cells were positive for Vimentin, HHF35 and alpha-SMA. The histiocytes were positive both for kp1 and PG-M1, suggesting that these cells were infiltrating cells from peripheral blood rather than histiocytic differentiation of tumor cells. Compared with ameloblastic fibroma, AFS showed much higher PCNA labeling index, suggesting higher proliferation activity of AFS.

Morphometric study of nucleolar organiser regions in ameloblastoma and basal cell carcinoma.

Ameloblastoma and basal cell carcinoma share histological similarities. Morphometric analysis of nucleolar organiser regions (NORs) from ameloblastoma and basal cell carcinoma (BCC) was carried out by silver (Ag) staining. Mean counts were lower in ameloblastoma (1.652 +/- 0.032) compared to those in BCC (2.354 +/- 0.054). Ameloblastoma presented one or two NORs per nucleus, in a narrow distribution (one to four NORs per nucleus). In contrast, BCC exhibited two or three NORs per nucleus, in a broad distribution (one to six NORs per nucleus). Perimeter and area measurements of AgNOR dots yielded significantly higher mean values for ameloblastoma. Our data suggest that most BCC cells are in mitosis, showing small and numerous NORs in each nucleus, while ameloblastoma cells are in interphase, showing one or two large NORs in each nucleus. Although ameloblastoma and BCC are neoplasms with similar growth patterns, they have cell populations with statistically significant differences in AgNOR patterns.

Odontogenic myxoma of the jaws: a clinical, radiologic, immunohistochemical, and ultrastructural study.

Ten cases of odontogenic myxoma were evaluated radiologically, histologically, and histochemically. Ultrastructural examination was performed in five cases. Stellate cells with branching processes were seen in an abundant acid mucopolysaccharide background. Occasionally macrophages were found in the tumors. In two cases islands of inactive odontogenic epithelium were identified. The ultrastructural features suggest that many lesional cells are very similar to a myofibroblast. With the avidin-biotin complex immunohistochemical technique, the lesions were tested with antibodies to S- 100 protein, neuron-specific enolase, neurofilaments, glial fibrillary acid protein, keratin, desmin, muscle-specific actin, and vimentin. All the lesions were found to be positive for vimentin and muscle-specific actin, and negative for the rest. The results of our study seem to confirm the muscle-specific actin-positivity of odontogenic myxomas as previously reported.

Nucleolar organizer regions (AgNORs) in odontogenic cysts and ameloblastomas.

The aim of this study was to determine whether nucleolar organizer regions (AgNORs) may be of value in distinguishing various odontogenic cysts from the unicystic ameloblastoma. Histological sections were prepared from fifteen cases each of odontogenic keratocyst, residual cyst, dentigerous cyst, unicystic ameloblastoma and conventional ameloblastoma. In each case intra-nuclear AgNOR dots were counted in 100 consecutive basal nuclei. Statistical comparison of the least squares means showed that those areas of unicystic ameloblastomas lined by characteristic epithelium had a significantly lower AgNOR count than the other groups (P < 0.05). The dentigerous cysts had significantly higher AgNOR counts than the residual cysts and unicystic ameloblastomas (P < 0.05). These differences may or may not be indicative of variations in metabolic, proliferative or transcriptional activity. We conclude that AgNOR counts are not of diagnostic significance and cannot be used to distinguish the various odontogenic cysts from one another nor from the unicystic ameloblastoma.

Myxoma of the jaws with an unusual intracellular banded structure.

Myxoma of the jaw is a rare odontogenic tumor, probably derived from the dental apparatus. The case described here was studied by both light and electron microscopic methods. Stellate cells with branching processes were reported in an abundant acid mucopolysaccharide stroma, and ultrastructurally these cells were seen to be fibroblast. Occasionally myxoblasts and macrophages were reported in the tumor. No odontogenic epithelium was identified, while an intracellular synthesis of cross-striated fibrils was observed. The ultrastructural features suggest that the connective tissue cell is the proliferating component of the tumor and is very similar to a fibroblast.

African Burkitt's lymphoma: case report and light and electron microscopic findings.

An African Burkitt's lymphoma occurred in a 9-year-old American boy who had jaw tumors, proptosis, and abdominal masses. Histologically, the tumor consisted of a monotonous overgrowth of undifferentiated lymphocytes with a "starry sky" appearance. The differential diagnosis of African versus American form and Burkitt's lymphoma versus non-Burkitt's lymphoma is discussed.

Granular cell lesions of the jaws and oral cavity: a clinicopathologic, immunohistochemical, and ultrastructural study.

A clinicopathological, immunohistochemical, and ultrastructural study of 44 oral granular cell lesions was performed. A total of 35 mucosal granular cell tumors, 4 granular cell ameloblastomas, 1 lichen planus with granular cell change, and 3 congenital epulides of the newborn were studied. Pseudoepitheliomatous hyperplasia was found to occur in only a minority of these cases. Immunohistochemically, the majority of granular cell lesions were uniformly positive for S-100 protein and focally positive for vimentin in one half of the cases, suggestive of origin from a Schwann cell or a precursor mesenchymal cell. Congenital epulis of the newborn and central odontogenic granular cell tumor were negative for S-100 protein, epithelial membrane antigen (EMA), and prekeratin, suggesting a mesenchymal origin for these lesions.

Giant cell lesion of the jaw. Case report.

A case is presented of a male patient affected by a giant cell lesion of the jaw, which had two recurrences in 8 years. Histologically, the lesion appeared to be composed of giant cells and mononuclear cells. Histoenzymatic study demonstrated acid phosphatase in both types of cells, and beta-glucuronidase in giant cells only. In some nuclei of giant cells, ultrastructural investigation showed filaments or microtubular structures of variable length, with irregular transverse periodicity, in addition to other expected findings. These characteristic features, found in giant cells of some giant cell tumors of the long bones, have never before been reported in a giant cell lesion of the jaw. The results are considered in order to assess the diagnosis, and the pathologic profiles of giant cell reparative granuloma, and of giant cell tumor are critically discussed.

Immunohistochemical localization of intermediate filament proteins in calcifying epithelial odontogenic tumors.

Three calcifying epithelial odontogenic tumors (CEOT) were examined immunohistochemically. The localization of intermediate filaments was characterized through the use of polyclonal anti-keratin antiserum (TK which detects 41-65 kd keratins), 2 monoclonal keratin antibodies (PKK1 specific for the 44, 46, 52 & 53 kd keratins and KL1, specific for the 55-57 kd keratins) and monoclonal antibodies for vimentin and desmin. The tumor epithelial cells were slightly positive or negative for PKK1 detectable keratins, but slightly to strongly positive for KL1 and TK antibodies. Tumor epithelium was slightly positive for vimentin but negative for desmin. The tumor foci were composed of both dark-staining and pale-staining cells; the former had a more intense reaction with KL1 and TK antibodies than the latter. Homogeneous acellular material was either PAS-positive or negative, with or without calcification, and keratin-negative.