Role of fine needle aspiration cytology in the preoperative presumptive diagnosis of ameloblastoma

OBJECTIVE: To determine the role of fine needle aspiration cytology (FNAC) on the preoperative presumptive diagnosis of ameloblastoma. STUDY DESIGN: Sixty-three patients, diagnosed preoperatively and postoperatively with ameloblastoma, were evaluated between 1990 and 2003. The patients were classified according to whether they were diagnosed with ameloblastoma preoperatively or postoperatively, on histologic examination. RESULTS: The accuracy rate for ameloblastoma was 0.95% for all biopsy methods, while the incisional biopsy rate was 75.00%. Concerning clinical diagnosis, ameloblastoma was mistaken mostly (56.41%) for odontogenic cysts (22 of 39). CONCLUSION: FNAC should be utilized more commonly on intraosseous and soft tissue lesions in the oral and maxillofacial regions, to obtain sufficient material. It is convenient, inexpensive and noninvasive as compared with other biopsy methods.     

Incidence and Overall Survival of Malignant Ameloblastoma

BackgroundMalignant ameloblastoma, comprising metastasizing ameloblastoma and ameloblastic carcinoma, represents 1.6–2.2% of all odontogenic tumors. Due to its rare nature, malignant ameloblastoma has only been reported in the literature in small case series or case reports. Using the Surveillance, Epidemiology and End-Results (SEER) database, we have performed a population-based study to determine the incidence rate and the absolute survival of malignant ameloblastoma.MethodUsing the International Classification of Diseases for Oncology (ICD-O) codes 9310/3 and 9270/3, data from the SEER database were used to calculate the incidence rate and absolute survival rate of population with malignant ameloblastoma.ResultsThe overall incidence rate of malignant ameloblastoma was 1.79 per 10 million person/year. The incidence rate was higher in males than females and also higher in black versus white population. The median overall survival was 17.6 years from the time of diagnosis and increasing age was associated with a statistically significant poorer survival.ConclusionsTo our best knowledge, we report the largest population-based series of malignant ameloblastoma. The incidence rate was 1.79 per 10 million person/year and the overall survival was 17.6 years.     

Cytology of recurrent ameloblastoma with malignant change. A case report

BACKGROUND: Ameloblastoma is a rare tumor of the jaw that arises from the odontogenic epithelium. Ameloblastomas have a propensity for local recurrence and, rarely, for metastasis. The term malignant ameloblastoma is reserved for those metastasizing tumors that retain the typical morphology of ameloblastoma. Fine needle aspiration (FNA) reports on ameloblastomas are scant, and those on malignant ameloblastomas are still more so. CASE: In a case of malignant ameloblastoma diagnosed by FNA cytology, the clinical presentation was that of a malignant neoplasm. FNA smears were highly cellular and showed isolated, scattered cells and small groups of basaloid cells and polygonal squamous epithelial cells. Stellate and spindle-shaped cells were also seen in the background. The cytologic diagnosis was subsequently confirmed on histopathology. CONCLUSION: The characteristic combination of cells in FNA smears facilitated the diagnosis of ameloblastoma. Since the biologic behavior of the tumor was that of a malignant neoplasm, the slides were reviewed. The cytologic smears did not exhibit sufficient features of malignancy to label the lesion malignant.     

Granular cell ameloblastoma of the jaw. A report of two cases with fine needle aspiration cytology

BACKGROUND: Fine needle aspiration cytology (FNAC) of jaw tumors has not been studied extensively. Ameloblastomas are jaw tumors that show a wide morphologic spectrum and thus may pose some diagnostic difficulties. Of the many types, granular cell ameloblastoma (GCA) is an uncommon variant that possesses distinctive features. To the best of our knowledge, there have been no previous reports on the cytologic findings of GCA. We present two cases diagnosed by FNAC. CASES: Two cases of GCA were diagnosed on cytology and subsequently confirmed on histology. Both patients presented with a large, lytic jaw tumor. FNAC smears showed characteristic granular cells along with spindle and basaloid cells. CONCLUSION: Although GCAs are rare tumors, they possess distinctive features that permit an accurate diagnosis, provided that this entity is kept in mind. This tumor has to be differentiated from cystic odontogenic lesions, epulis and granular cell myoblastoma. An accurate preoperative diagnosis also helps the surgeon to plan more extensive surgery as these tumors show a great propensity for malignant change and metastases.     

Encephalocraniocutaneous lipomatosis accompanied by maxillary compound odontoma and juvenile angiofibroma: report of a case

BACKGROUND: Encephalocraniocutaneous lipomatosis (ECCL) is a rare neurocutaneous syndrome characterized by congenital cutaneous, ocular, and neurologic abnormalities, which may be pronounced in the head and neck. CASE: In this article we present a well-documented case of a six-year-old boy with ECCL associated with oral manifestations. In this case, typical features such as large lipomatous brown pigmented plaques of the top of the skull with overlying alopecia, ptotic eyelid with decreased function, bulbar conjunctiva lipodermoid, microcalcifications and atrophy of cerebral parenchyma, and the widening of the frontal subarachnoid space and the fissure of Sylvius were accompanied by intraoral lesions, maxillary compound odontoma, and juvenile extranasopharyngeal angiofibroma of the gingiva. CONCLUSIONS: Although cases of odontomas have already been described and angiofibromas are a quite common extraoral finding, to our knowledge this is the first case of intraoral evaluation of both extranasopharyngeal juvenile angiofibroma and maxillary compound odontoma in ECCL syndrome.     

Maxillary sinusitis as an indicator of respiratory health in past populations

Chronic infectious respiratory disease in a past human population is investigated through the quantification of maxillary sinusitis among Iroquoian horticulturists. Three hundred forty-eight right and left maxillae of a Southern Ontario Iroquoian skeletal sample, Uxbridge Ossuary, ca. AD 1440, were examined for evidence of chronic infection (minimum number of individuals = 207: 114 adults, 22 adolescents, 38 juveniles and 33 infants). Modern clinical criteria were applied to differentiate lesions of respiratory and dental origin. Osseous lesions of the maxillary sinuses were observed in 50% of the individuals examined. These lesions are morphologically consistent with nonspecific lesions observed in other past populations that have been attributed to the presence of pathogens. The prevalence of maxillary sinusitis increases with age. Osseous changes suggestive of maxillary sinusitis of respiratory origin are at a maximum prevalence in juveniles and adolescents. In adults, infection of dental origin becomes a confounding factor in the identification of sinusitis of respiratory origin. Fifteenth century Iroquoians were experiencing high airborne pathogen levels and poor indoor air quality. The prevalence of maxillary sinusitis and the exploration of the origin of tissue injury may contribute to our reconstruction of the quality of life and the respiratory health status of past human populations.     

Activation of Wnt signalling reduces the population of cancer stem cells in ameloblastoma

ObjectivesThe treatment of ameloblastoma, an odontogenic epithelial tumour destroying jawbone, mainly depends on radical destructive resections. Other therapeutic options are limited by the characteristics of ameloblastoma, such as high recurrence rates and resistance to radiation and chemotherapy, which implies possible existence of cancer stem cells (CSCs) in ameloblastoma. Here, we identified a putative CSC population in immortalized and primary human ameloblastoma cells and examined possible therapeutic reagents to reduce the CSC population.MethodsWe investigated subpopulations of AM‐1 cell line and human ameloblastoma cells using immunocytochemistry and flow cytometry and the effects of Wnt signalling activators on the 2‐ and 3‐dimensional cultured ameloblastoma cells using molecular biological analyses.ResultAmong heterogenous ameloblastoma cells, small‐sized and round‐shaped cells were found to be proliferative and expressed a marker of dental epithelial stem cells, SRY‐box 2 (Sox2). Exogenous activation of Wnt signalling using glycogen synthase kinase 3β inhibitors, lithium chloride (LiCl) and valproic acid (VPA), increased the cell size and decreased proliferation of cells and expression of Sox2 in 2 dimensionally cultured AM‐1 and human primary ameloblastoma cells. Furthermore, the growth of 3 dimensionally cultured AM‐1 cells as suspended or embedded in gel was suppressed by treatment with Wnt signalling activators, VPA and CHIR99021, or antibodies to sclerostin, an antagonist of Wnt signalling.ConclusionWe suggest that Wnt signalling activators are potential drug candidates to suppress CSCs in ameloblastoma.     

Odontogenic tumors in Nigerian children and adolescents- a retrospective study of 92 cases

Background

Tumours arising from odontogenic tissues are rare and constitute a heterogenous group of interesting lesions. The aim of this study was to determine the relative frequency of odontogenic tumors (OT) among Nigerian children and adolescents 19 years or younger.

Patients and methods

The histopathology records were retrospectively reviewed for all the tumors and tumor-like lesions of the oral cavity and the jaws seen in children and adolescents ≤ 19 years seen between January 1980 and December 2003. Hematoxylin and eosin-stained sections were re-evaluated and the diagnosis in each case was confirmed or modified according to World Health Organization (WHO) classification, 1992; and were subjected to analysis of age, sex, site of tumor and histopathologic type.

Results

A total of 477 tumors and tumor-like lesions were seen in patients ≤ 19 years during the period of the study. Of these, 92 (19.3%) were odontogenic tumors. Benign odontogenic tumors constituted 98.9% of the cases seen, while only 1 case (1.1%) of malignant variety was seen during the period. The mean (SD) age of patients was 14.9 (± 3.1) years (range, 4–19 years). Male-to-female ratio was 1:1; and mandible-to-maxilla ratio was 2.7:1. OT's were most frequently seen in patients aged 16–19 years (46.7%) and the least number (2.2%) were found in patients aged 0–5 years. Among nine histologic types of OT seen, ameloblastoma (48.9%), adenomatoid odontogenic tumor (19.6%) and odontogenic myxoma (8.7%) were predominant. Multicystic/solid and unicystic variants of ameloblastoma were diagnosed in 40 (89%) and 5 (11%) cases respectively.

Conclusions

Odontogenic tumors are relatively common in children and adolescents in Nigeria. One out of every 5 children and adolescents with tumors and tumor-like lesions of oral cavity and the jaws seen in this study had a diagnosis of odontogenic tumor.

     

Diagnosis of radiolucent lesions of the jaw by fine needle aspiration biopsy

Radiolucent lesions of the jaw, representing a variety of metabolic, inflammatory, developmental, neoplastic and other disorders, may be quite variable in appearance. Fine needle aspiration biopsy, performed on 57 patients who presented with oral abnormalities, was used in an attempt to differentiate the pathologic processes in the 23 patients with radiolucent changes resulting from bony involvement. Most aspirations were performed on an outpatient basis, and the cytologic findings were correlated with the clinical course and subsequent surgical findings. The entities encountered included ameloblastoma, a variety of odontogenic cysts and inflammatory and infectious processes, such as actinomycosis and giant-cell and eosinophilic granulomas. An unusual salivary gland lesion was also observed. The aspiration biopsy proved to be a valuable adjunct method for the preoperative diagnosis of radiolucent lesions of the jaws. A discussion of the differential diagnostic considerations is presented.     

Cytologic appearance of carcinosarcoma (malignant ameloblastoma and fibrosarcoma) of the maxilla. A case report.

The cytologic appearance of a carcinosarcoma (malignant ameloblastoma and fibrosarcoma) of the maxilla in a 63-year-old man is described. On his first admission the diagnosis of malignant ameloblastoma was made on biopsy. After five surgical excisions, radiotherapy and chemotherapy, the diagnosis was changed to carcinosarcoma because the stromal cells of the tumor had become malignant. Aspiration biopsy cytology of the tumor, with a cystic lesion found at the left suborbital area, revealed malignant epithelial cells, indicating malignant ameloblastoma. Imprint smears of both surgically resected and autopsy material showed two types of malignant neoplastic cells, of epithelial and mesenchymal origin.     

Establishing the Natural History and Growth Rate of Ameloblastoma with Implications for Management: Systematic Review and Meta-Analysis

BackgroundAmeloblastoma is the second most common odontogenic tumor, known to be slow-growing, persistent, and locally aggressive. Recent data suggests that ameloblastoma is best treated with wide resection and adequate margins. Following primary excision, bony reconstruction is often necessary for a functional and aesthetically satisfactory outcome, making early diagnosis paramount. Despite earlier diagnosis potentially limiting the extent of resection and reconstruction, an understanding of the growth rate and natural history of ameloblastoma has been notably lacking from the literature.MethodA systematic review of the literature was conducted by reviewing relevant articles from PubMed and Web of Science databases. Each article’s level of evidence was formally appraised according to the Centre of Evidence Based Medicine (CEBM), with data from each utilized in a meta-analysis of growth rates for ameloblastoma.ResultsLiterature regarding the natural history of ameloblastoma is limited since the tumor is immediately acted upon at its initial detection, unless the patient voluntarily refuses a surgical intervention. From the limited data, it is derived that the highest estimated growth rate is associated with solid, multicystic type and the lowest rate with peripheral ameloblastomas. After meta-analysis, the calculated mean specific grow rate is 87.84% per year.ConclusionThe growth rate of ameloblastoma has been demonstrated, offering prognostic and management information, particularly in cases where a delay in management is envisaged.     

Intercellular signaling between ameloblastoma and osteoblasts

Ameloblastoma is an odontogenic tumor located in the bone jaw with clinical characteristics of extensive bone resorption. It is a locally invasive tumor with a high recurrence rate despite adequate surgical removal. In bone disease, tumors and other cells including osteoblasts, osteoclasts, and osteocytes in the bone microenvironment contribute to the pathogenesis of tumor growth. However, the effect of osteoblasts on ameloblastoma cells is not well-understood, and there has been limited research on interactions between them.This study investigated interactions between ameloblastoma cells and osteoblasts using a human ameloblastoma cell line (AM-3 ameloblastoma cells) and a murine pre-osteoblast cell line (MC3T3-E1 cells). We treated each cell type with the conditioned medium by the other cell type. We analyzed the effect on cytokine production by MC3T3-E1 cells and the production of MMPs by AM-3 cells. Treatment with AM-3-conditioned medium induced inflammatory cytokine production of IL-6, MCP-1, and RANTES from MC3T3-E1 cells. The use of an IL-1 receptor antagonist suppressed the production of these inflammatory cytokines by MC3T3-E1 cells stimulated with AM-3-conditioned medium. The MC3T3-E1-conditioned medium triggered the expression of MMP-2 from AM-3 cells. Furthermore, we have shown that the proliferation and migration activity of AM-3 cells were accelerated by MC3T3-E1 conditioned media.In conclusion, these intercellular signalings between ameloblastoma cells and osteoblasts may play multiple roles in the pathogenesis of ameloblastoma.     

Peripheral calcifying cystic odontogenic tumour of the maxillary gingiva

ABSTRACT: BACKGROUND: Odontogenic tumors are lesions that are derived from remnants of the components of the developing tooth germ. The calcifying cystic odontogenic tumor or calcifying odontogenic cyst is a benign cystic neoplasm of odontogenic origin that is characterized by an ameloblastoma-like epithelium. Calcifying cystic odontogenic tumor may be centrally or peripherally located, and its ghost cells may exhibit calcification, as first described by Gorlin in 1962. Most peripheral calcifying cystic odontogenic tumors are located in the anterior gingiva of the mandible or maxilla. CASE PRESENTATION: Authors report a rare case of a peripheral calcifying cystic odontogenic tumor of the maxillary gingiva. A 39-year-old male patient presented with a fibrous mass on the attached buccal gingiva of the upper left cuspid teeth. It was 0.7-cm-diameter, painless and it was clinically diagnosed as a peripheral ossifying fibroma. After an excisional biopsy, the diagnosis was peripheric calcifying cystic odontogenic tumor. The patient was monitored for five years following the excision, and no recurrence was detected. CONCLUSIONS: All biopsy material must be sent for histological examination. If the histological examination of gingival lesions with innocuous appearance is not performed, the frequency of peripheral calcifying cystic odontogenic tumor and other peripheral odontogenic tumors may be underestimated.     

Computerized tomography of the head in patients with epilepsy

A detection of structural changes in the brain of epileptic patients is of importance to the choice of therapeutical management. Incidence and character of lesions in CT-scans of the skull were analysed in the random group of epileptic patients. Normal areas in CT-scans were prevailing in young patients. Atrophic lesions to the brain increased with the patients' age and duration of the disease. Normal results were obtained in post-traumatic epilepsy and that of unknown etiology similarly to atrophic lesions whereas localized lesions were found in all patients with cerebral tumors. Partial epilepsy, especially of short duration, was characterized by high incidence of localized lesions. Normal EEG records were rare in patients with localized lesions detected with CT-scans whereas normal CT-scans may be related to abnormal EEG record. Presence of the localized lesions in some patients and atrophic areas did not limit clinical results of monitored therapy. CT-scanning of the skull should be performed in case of all patients with epilepsy even if there are no significant changes in EEG records or clinical status.     

A longitudinal study of the growth pattern of the maxillary sinus in the pig-tailed macaque (Macaca nemestrina)

The ontogeny of sexual dimorphism in maxillary sinus size in a nonhuman primate was studied longitudinally for a period of 8 years in 25 female and 25 male Macaca nemestrina via lateral cephalograms. The maxillary sinus was traced and its area digitized. The growth of female maxillary sinuses was described with a Gompertz model; the best fit to the male data was obtained by the logistic model. Growth curves and confidence intervals revealed that the sinuses grew in a similar fashion for 3-4 years in both sexes. After this, female sinuses achieved a plateau in their development while male sinuses continued to grow. Confidence intervals suggested that size dimorphism appeared at the age of 6.3 years. Lowess regression indicated growth spurts in both sexes. Females experienced an earlier and smaller spurt than males. Sexual dimorphism in maxillary sinus size seems to represent a combination of differences in velocity and length of growth. This study indicates that growth of the maxillary sinus follows closely the growth in body size. Nevertheless, due to the variation in sinus size in Macaca, it is questionable if body size is the main determinant of maxillary sinus size. It is suggested that Macaca, with its wide geographic range and different environments, is an especially appropriate genus to use to test hypotheses about the evolution of skull pneumatization in primates.     

黑胸大蠊下颚须和下唇须上感器扫描电镜观察

利用扫描电子显微镜观察了黑胸大蠊Periplanetafuliginosa(Serville)成虫下颚须和下唇须上的感器形态。结果发现,在黑胸大蠊下颚须和下庸须末节顶端何感器密集区,尤其是下颚须第5节内侧顶端,有一狭长沟壑,内有大量的带槽锥形感器。通过重点观察感器密集区,发现主要有5~6种类型感器,分别为带槽锥形、毛形、刺形、钟形、齿状、针形感器,其中有些感器又可分为几种亚类型。比较研究发现下颚须和下唇须上感器类型除了带槽锥形感器以外基本相似,只是数量上有区别。     

Talon cusp from two archaic period cemeteries in North America: implications for comparative evolutionary morphology

Talon cusps are rare morphological features of the anterior dentition that represent a spectrum of lingual cingulum diversity. In this paper, talon cusp prevalence is described in two Archaic period North American samples, Windover Pond (Florida) and Buckeye Knoll (Texas). Given the early date of these cemeteries (~7500 BP), these specimens represent the oldest reported cases of lingual talon cusp in the New World, and perhaps globally. Windover preserves three cases of talon cusp (representing three different individuals) affecting the permanent maxillary lateral incisors. The sample frequencies were 1.8% and 3.1% for the left and right maxillary lateral incisors, respectively. Buckeye Knoll preserves four cases of talon cusp representing three individuals. Talon cusps at this site were distributed throughout the maxillary anterior dentition, including a permanent maxillary central incisor, bilateral permanent maxillary lateral incisors, and a deciduous maxillary lateral incisor. The multicomponent nature of this site complicates sample frequency calculation with by-tooth estimates ranging from 3.6% to 25%. This paper discusses the difficulties with comparative frequency estimation, resulting from a proliferation of terminology that is discipline-specific. Understanding the evolutionary basis and significance of dental morphological variation requires an inclusive approach to the comparative literature that focuses on homology within the context of odontogenetic process.     

Mouse-killing in the rat: effects of sensory deficits on attack behaviour and stereotyped biting.

Sensory transections were performed in rats that killed mice after food-deprivation and subsequent satiation. Following partial maxillary or combined maxillary and optic deafferentation, but not after optic lesions alone, the number of mouse-kills declined sharply. This decline was accounted for by approximately a 50 per cent decrease in the number of mouse-presentations in which attack-behaviour took place and in the occurrence of attack-behaviour that did not always lead to a kill because rats frequently failed to bite. Furthermore, examination of killed mice revealed a shift in the distribution of body-bites away from the rostral regions normally seized by rats to more caudal areas of the mouse's body. Results indicate that certain stimulus-characteristics of mice mediated by the maxillary and optic nerves are important determinants of attack-behaviour and stereotyped biting in the rat.     

Sensory organs of the antennae and mouthparts of beetle larvae (Coleoptera)

The sensilla located on the antennae and maxillary and labial palps of the larvae of 64 beetle species from 22 families were studied using electron microscopy. The larvae of beetles living in different habitats and having different trophic specializations possess a uniform structure of the sensory organs. They are composed of two groups of sensilla on the apical and subapical segments of the antennae, one apical group of sensilla on both maxillary and labial palps, and one or several digitiform sensilla on the lateral surface of the maxillary and, occasionally, labial palp. The external morphology of the sensory organs is adaptive and represents modifications of the initial type. Band-shaped sensilla or placoid sensilla, clearly different from the initial sensory organs, appear in some taxa as rare exceptions, while other groups display either partial reduction of the receptor organs (Gyrinidae) or reduction of the cuticular parts of the sensilla (Cantharidae).     

Regulation of IL-6 and IL-8 production by reciprocal cell-to-cell interactions between tumor cells and stromal fibroblasts through IL-1α in ameloblastoma

Ameloblastoma is an odontogenic benign tumor that occurs in the jawbone, which invades bone and reoccurs locally. This tumor is treated by wide surgical excision and causes various problems, including changes in facial countenance and mastication disorders. Ameloblastomas have abundant tumor stroma, including fibroblasts and immune cells. Although cell-to-cell interactions are considered to be involved in the pathogenesis of many diseases, intercellular communications in ameloblastoma have not been fully investigated. In this study, we examined interactions between tumor cells and stromal fibroblasts via soluble factors in ameloblastoma.