Ameloblastomas formed 1.1 percent of all oral pathology cases reported. The race, sex and age group distribution of 133 cases are shown. The peak age incidence (70.6 percent) was between 11-40 years. The mandible was involved 9 times more commonly than the maxilla. The anatomical sites of distribution, clinical and radiological features, histological variants and their correlation are discussed. Twenty two patients (15 percent) had ameloblastomas associated with a dentigerous cyst and/or unerupted teeth. Ameloblastomas with the above clinical features represented a much less aggressive form of neoplasm. The authors could not correlate histological variants of ameloblastoma with recurrence rates. The various treatment methods and the respective recurrence rates are outlined. Radiotherapy and marsupialization as treatment of ameloblastoma are not recommended. The indications for enucleation curettage, resection en bloc, segmental resection and hemimandibulectomy
are emphasized. Ameloblastomas involving the maxilla should be treated by complete removal en bloc with a margin of normal tissue. Since ameloblastoma has the capacity to recur after several years of apparent cure patients who have been treated for ameloblastoma must be followed up periodically during their life time. So far no case of ameloblastoma in this study has shown evidence
ofmetastasis.
This is a case report of a recurrent lesion diagnosed histologically as a unicystic ameloblastoma. The concomitant presence of a traumatic neuroma was observed within the wall of the recurrent lesion. The mode of development of the traumatic neuroma, and the reason for the recurrence were presented.
This article consists of two selected case reports of a recently named odontogenic tumour, unicystic ameloblastoma. The clinical and radiographic findings of the two cases mimic that of odontogenic cysts but not dentigerous cysts as in most reported, cases. Histologically, either a normal or ameloblastomatous cyst lining is evident. Other features of ameloblastoma are present within the cyst wall or as luminal nodules within the cystic space. A review of the literature indicates that this is a non-aggressive tumour with a low recurrence rate.
Clinical, radiological and histological characteristics of the peripheral ameloblastoma are briefly outlined. A case found occurring in the palate and presenting with atypical histological features is reported. The differential diagnosis of this lesion, its treatment and histogenesis are discussed.
This report details a case of mandibular peripheral ameloblastoma having a clear cell component. The latter consisted of ovoid cells with vacuolated or clear cytoplasm and vesicular or pyknotic nuclei that may be disposed as discrete clusters or show direct transition from typical acanthomatous areas. Comparison of this lesion with other odontogenic and nonodontogenic tumors that contain clear cells is discussed in the context of the differential diagnosis.
Granular cell ameloblastomas are uncommon lesions accounting for about 3-5% of all histologic subtypes of ameloblastoma. The plexiform granular cell odontogenic tumour, on the other hand, is a newly described lesion characterised by a monophasic plexiform pattern of granular cells. This article reports a tumour found occurring in the left mandible of a 67-year-old Indian male which histologically showed features of both the aforementioned lesions.
A case is described of ameloblastoma of maxilla presenting with numerous calcified keratin pearls. The significance of cellular variation in relation to the behavioural potential of the ameloblastoma in general is briefly discussed.
Four cases of either combined occurrence of ameloblastoma and odontogenic keratocyst or a rare keratinising variant of ameloblastoma are presented. The cardinal histomorphologic characteristics are simultaneous occurrence of ameloblastomatous epithelial islands with central keratinisation and multiple keratinising cysts. Immunohistochemically the tumour elements were keratin positive and occasionally S-100 protein and desmin positive. Major differential diagnosis of these neoplasms are discussed.
Granular cell ameloblastoma (GCA) is a well recognized variant of follicular ameloblastoma with extensive granular cell change. In contrast, plexiform granular cell odontogenic tumor (PGCOT) is a rare and recently described lesion characterized histologically by a monophasic plexiform pattern of granular cells. In this paper, two cases of an unusual granular cell odontogenic tumor exhibiting combined features of these two entities are described along with their immunohistochemical characteristics. The granular cells of both the GCA and PGCOT areas showed similar patterns of expression for keratin and S-100, which differed from those of typical ameloblastoma. No reactivity for desmin or vimentin was noted. The histomorphologic and immunohistochemical features of these hybrid tumors suggest that the granular cells present have a common origin, most probably the odontogenic epithelium.
Seventeen cases of desmoplastic ameloblastoma were examined immunohistochemically. Immunoperoxidase techniques were applied for detection of keratin, desmin, vimentin and S-100 protein expression in these tumors. The tumor epithelium of desmoplastic ameloblastoma exhibited weak, focal, inconstant keratin staining, weak, variable expression of S-100 protein, desmin immunoreactivity of mild to moderate intensity and vimentin non-reactivity. The pertinent literature on the immunohistochemistry of ameloblastomas is briefly reviewed.
Seventeen cases are reported of desmoplastic variant of ameloblastoma of the jaws observed during the years 1967-1991. There were 12 females and 5 males, and these consisted of 7 Chinese, 6 Malays, 2 Indians, 1 Sikh and 1 Kadazan. Their ages at diagnosis ranged from 21-60 years with a mean of 36.6 years. There were 10 mandibular and 7 maxillary tumours. Of these, 14 cases involved the anterior segment with extension to the premolar region in 5 cases. 60% of cases were radiologically suggestive of fibro-osseous lesions. The main mode of treatment was resection and 1 case presented with recurrence. The findings of this study were compared with those of previous reports.
A case is described of ameloblastoma of the mandible presenting with multiple recurrences and subsequent extension to the maxilla with resultant transformation into an aggressive (malignant?) epithelial odontogenic ghost cell tumour. The latter is a rare, biologically virulent entity that affects mainly males, exhibits a preference for the maxilla and is histologically characterized by atypical malignant odontogenic epithelium associated with areas of ghost cell formation and varying amounts of dentinoid.
A case of unicystic ameloblastoma which recurred after 15 years showing unusual histological features is reported. The prominent pseudo-glandular features present are described. This case highlights the importance of extensive histological examination for more characteristic features of ameloblastoma to reach a correct diagnosis.
Two cases of either peripheral odontogenic fibroma (POF) (WHO type) or peripheral ameloblastoma are reported. Their immunohistochemical characteristics were investigated in an attempt to clarify their histogenesis. The results showed that the epithelial component of this neoplasm tended to retain its distinct odontogenic character and expressed a keratin profile different from that of the overlying oral epithelium from which both cases most probably originated. The connective tissue element of these tumors was vimentin-positive and S-100 protein negative, confirming their mesodermal nature but precluding the possibility of ectomesenchymal derivation. No reactivity for desmin was noted.
In the recent World Health Organization classification of odontogenic tumours, desmoplastic ameloblastoma has been characterized as a variant of ameloblastoma, with specific clinical, radiographical, and histological features. Till date, 145 cases have been reported in Japanese, Chinese, Malaysian, Western, and African populations, with very few cases described in Indians. Here, we report five cases in the Indian population. The male to female ratio was 3:2. The mean age at diagnosis was 33.2 years. Four of the tumours were located in the maxilla, in the anterior premolar region. The lone mandibular tumour was located anteriorly, crossing the midline. Three of the tumours had a mixed radiologic appearance with poorly defined borders. Unilocular change was seen in one of them. Two tumours presented as unilocular radiolucencies with specks of radiopacities and well-circumscribed borders. Histologically, irregular odontogenic islands, with a stretched-out 'kite-tail' appearance, were seen in a dense desmoplastic stroma. The peripheral layer of the epithelial islands was made up of flattened cells and the inner core was made up of spindle-shaped and, in some instances, squamous-shaped cells. In two cases, odontogenic epithelium in the form of follicles, typical of solid/multicystic ameloblastoma, was seen and these were typed as 'hybrid' variants. All the cases were treated by resection.
The purpose of this report is to document a case of unsuspected ameloblastoma involving the right man dibular subpontic region in a 38-year-old Cambodian female patient. This lesion was purportedly preceded by multiple radiolucencies which were diagnosed as radicular cysts and treated a few times in the past years by enucleation followed by endodontic therapy of the affected teeth. Bridgework restoration of the partially edentulous area was performed. This case report demonstrates radiographic changes that occurred in the periods before and after the diagnosis of ameloblastoma. The case may represent an example of radicular cysts and ameloblastoma occurring as a collision phenomenon, or the ameloblastoma may have arisen as a result of neoplastic transformation of the lining epithelium in an inflammatory odontogenic epithelial cyst.
Notch signaling has been implicated in cell fate decisions during odontogenesis and tumorigenesis of some odontogenic neoplasms; however, its role in solid/multicystic (SA), unicystic (UA), and recurrent (RA) ameloblastoma remains unclear. The aim of this study was to determine Notch receptor and ligand expressions in these subtypes and to speculate on their significance.
In mammals, the Notch gene family encodes four receptors (Notch1-4), and all of them are important for cell fate decisions. Notch signaling pathway plays an essential role in tooth development. The ameloblastoma, a benign odontogenic epithelial neoplasm, histologically recapitulates the enamel organ at bell stage. Notch has been detected in the plexiform and follicular ameloblastoma. Its activity in the desmoplastic ameloblastoma is unknown.
Ameloblastoma of the human jaw is an uncommon but clinically significant odontogenic epithelial neoplasm. The aim was to analyze the clinicopathologic characteristics of ameloblastoma in a Malaysian population.
Epithelial-to-mesenchymal transition (EMT) via the mechanism of transcription repression is a crucial process for the induction of invasiveness in many human tumors. Ameloblastoma is a benign odontogenic epithelial neoplasm with a locally infiltrative behavior. Twist, an EMT promoter, has been implicated in its invasiveness. The roles of the other transcription factors remain unclarified.