Ameloblastic Carcinoma

Ameloblastic carcinoma (AC) is a rare aggressive malignant epithelial odontogenic tumor of the maxillofacial skeleton with a distinct predilection in the mandible. It may appear de novo or originate from a pre-existing ameloblastoma or odontogenic cyst. It exhibits cytological features of ameloblastoma and carcinoma. It may present as a cystic lesion with benign clinical features or as a large tissue mass with ulceration, significant bone resorption and tooth mobility. The clinical course of ameloblastic carcinoma is typically aggressive, with extensive local destruction. Direct extension of the tumour, lymph node involvement and metastasis to various sites has been reported. Wide local excision is the treatment of choice. Regional lymph node dissection should be considered and performed selectively. Radiotherapy and chemotherapy have limited role in the treatment of ameloblastic carcinomas. Close periodic reassessment of the patient is mandatory.     

Ameloblastic carcinoma: a clinicopathologic study and assessment of eight cases

The term ameloblastic carcinoma is differentiated from the term malignant ameloblastoma and is defined as an ameloblastoma in which there is histologic evidence of malignancy in the primary tumor or the recurrent tumor (or metastasis), regardless of whether it has metastasized. Eight cases of ameloblastic carcinoma from the Armed Forces Institute of Pathology (AFIP) are reported. The mean age of patients was 30.1 years, with no sex predilection noted. Seven cases involved the mandible and one involved the maxilla, with the posterior regions favored. The most common sign was swelling, although pain, rapid growth, trismus, and dysphonia also occurred. Lesions characteristically were evident as ill-defined destructive radiolucencies, with occasional radiopacities noted. Histologic features generally resembled those of conventional ameloblastoma but with cytologic features of epithelial malignant disease. The clinical course was uniformly aggressive with extensive local destruction and spread, frequent recurrences, and one case of neck node metastasis. The nomenclature and classification of odontogenic carcinomas are discussed, as well as entities that should be included in the differential diagnosis. Further reporting of ameloblastic carcinoma is encouraged.     

Ameloblastic carcinoma, secondary type: a case report

Malignant variants of ameloblastoma include metastasizing ameloblastoma, which microscopically appears benign but has metastasized and ameloblastic carcinoma that exhibits malignant histopathologic features. Ameloblastic carcinoma is classified into 2 types: a primary odontogenic malignancy and a secondary type resulting from malignant transformation of ameloblastoma. Most secondary ameloblastic carcinomas result from malignant transformation of a primary lesion after repeated postsurgical recurrences. Therefore it is rare to find an untreated secondary type presenting with histologic features of malignant transformation from an earlier benign lesion. We experienced a rare case of ameloblastic carcinoma, secondary type which might arise in an untreated ameloblastoma. The mechanism by which a preexisting benign ameloblastoma goes through a malignant transformation is also described.     

Ameloblastoma: analysis of 207 cases in a Nigerian teaching hospital.

OBJECTIVE: The aim of the study was to review all the cases of ameloblastoma seen at the Oral and Maxillofacial Surgery Clinic of the Lagos University Teaching Hospital, Nigeria, between 1980 and 2003. METHODS AND MATERIALS: In this retrospective study, case files and biopsy reports of new cases of ameloblastoma covering a 24-year period were retrieved and analyzed for sex, age on presentation, histologic type, and site distribution. RESULTS: A total of 207 cases of ameloblastoma were seen in the given period. One hundred and ninety-eight (95.7%) were benign, and 9 (4.3%) were malignant. A male-to-female ratio of 1.1:1 was found. The average ages on presentation for ameloblastoma and ameloblastic carcinoma were 31.67 and 46.44 years, respectively. The lesion was found to be more common in the premolar-molar region of the mandible. The most common histologic type was follicular ameloblastoma (25.1%). Nine (4.3%) cases of ameloblastic carcinoma were also reported. CONCLUSIONS: Ameloblastoma with a predilection for the posterior mandibular region is relatively common in our environment. Sex and site distributions are similar to previous reports in the literature.     

Ameloblastic Carcinoma of the mandible

Odontogenic carcinomas are rare lesions arising from dental embryogenic residues and have been designated by a variety of terms like malignant ameloblastoma, ameloblastic carcinoma, metastatic ameloblastoma or primary intra-alveolar epidermoid carcinoma. Ameloblastic carcinoma combines the histological features of ameloblastoma with cytological atypia, even in the absence of metastasis. The lesion has been reported to arise either from the odontogenic cyst or the ameloblastoma. Majority originate de novo and the remaining are malignant transformation of an ameloblastoma.     

Ameloblastic carcinoma: case report and review

The histologic classification for odontogenic carcinomas is still under revision; thus, the differentiation between the terms "malignant ameloblastoma" and "ameloblastic carcinoma" has not been definitely stated. Nevertheless, it is recommended to reserve the former for those lesions that, in spite of an apparently innocuous histology, have given origin to metastatic growths, and to apply the latter for those ameloblastomas in which there is histologic evidence of malignancy in the primary, recurrent or metastatic lesions. A case of an ameloblastic carcinoma in the mandible is presented. Histologically, it was characterized by areas with features of a typical ameloblastoma and areas with anaplastic appearances.     

Ameloblastic carcinoma ex ameloblastoma of the mandible with malignancy-associated hypercalcemia

Ameloblastoma is a rare, locally destructive, benign neoplasm of the jawbones, which arises from epithelium derived from the epithelial components of the developing tooth. Ameloblastic carcinoma is the term used to designate any ameloblastoma in which there is histologic evidence of malignancy in the primary tumor, regardless of whether it has metastasized. Most ameloblastic carcinomas are presumed to have arisen de novo, with few cases of malignant transformation of ameloblastoma being apparent. Hypercalcemia is the most common metabolic complication of malignancy. Although malignancy-associated hypercalcemia is often reported in association with other malignancies, it is exceedingly unusual in association with ameloblastoma, malignant ameloblastoma, or ameloblastic carcinoma. We describe a patient with multiple recurrences of ameloblastoma, with subsequent malignant transformation presenting with malignancy-associated hypercalcemia.     

Ameloblastic carcinoma of the maxilla. A case report

A case of an ameloblastic carcinoma in an unusual situation in the maxilla is presented. The lesion is characterized histologically by areas with features of a typical ameloblastoma and areas with anaplastic transformation. A Caldwell-Luc operation was followed by a recurrence after 3 years. Due to the advanced age and poor general health of the patient an enlarged, but not radical operation was performed. There is no evidence of metastatic tumour.     

Metastasizing Ameloblastoma – A perennial pathological enigma? Report of a case and review of literature

The Ameloblastoma is a slow growing locally invasive odontogenic epithelial neoplasm with a high recurrence rate and a low tendency to metastasize. Metastasis in Ameloblastoma was first described by Simmons and Emura in the 1920s. Slootweg and Muller proposed the term Malignant Ameloblastoma to describe a well-differentiated ameloblastoma that metastasizes but maintains the characteristic cytologic features of the original tumour and the term Ameloblastic Carcinoma to an ameloblastoma with malignant cytological features. About 2% of ameloblastomas undergo metastasis. So far there have only been two cases of Metastasizing Ameloblastoma reported from the Indian Subcontinent. We present the case of a 22-year-old male Indian patient, who presented with a diffuse swelling in the left posterior mandible. Radiographs revealed a multilocular radiolucency in the left mandible. On histopathological examination, the lesion was diagnosed as follicular ameloblastoma. Four years later the patient presented with a swelling in the left submandibular region. Histological examination revealed metastatic ameloblastoma within the cervical lymph node.     

Desmoplastic ameloblastoma featuring basal cell ameloblastoma: a case report

The desmoplastic ameloblastoma is a histological variant of ameloblastoma. The neoplastic epithelial islands seen in desmoplastic ameloblastoma are small and ameloblastic cells are rare. Basal cell ameloblastoma is also a rare variant of ameloblastoma, in which the tumor is composed of more primitive cells and has even fewer features of peripheral palisading. This report describes the case of a 17-year-old female with an ameloblastoma in the right anterior maxilla. Orthopantomography and computed tomography showed a well-defined lesion in the right maxilla. A partial maxillectomy for tumor resection was performed under general anesthesia. Histologically, ameloblastic tumor cells were seen with dense collagenous stroma and the tumor cells showed primarily basal cell variants of ameloblastoma. After 7 years of follow-up, clinical and radiographic examinations have revealed no evidences of recurrence.     

Ameloblastic carcinoma: a case report with radiological features of computed tomography and magnetic resonance imaging and positron emission tomography

Ameloblastic carcinoma is a rare malignant odontogenic carcinoma that has metastatic potential, and because of its rare incidence, there are few reports focusing on its radiologic imaging. If it shows aggressive appearances, it can be diagnosed as malignant tumor. But in case of negative appearance, it is difficult to distinguish ameloblastic carcinoma from ameloblastoma. We report a case of ameloblastic carcinoma of the maxilla in a 76-year-old female patient with radiologic images and pathologic features.     

牙源性肿瘤的印片细胞学与组织学比较的探讨

本文对35例牙源性肿瘤的印片细胞学及组织学图像进行了比较性探讨。体会到印片细胞学不仅方便、快捷，可以鉴别组织类型。并且牙源性肿瘤为颌骨内肿瘤，不方便做术前活检；肿瘤内含有骨小梁及钙化物，又不能做冰冻切片。而在手术中取材用印片细胞学进行快速诊断，指导制订治疗计划，有其特殊的，不可替代的优点，值得向同道们介绍推广。     

Ameloblastomatous calcifying odontogenic cyst: a rare histologic variant

Calcifying odontogenic cyst (COC) is an uncommon developmental odontogenic cyst first described by Gorlin in 1962. It is considered as extremely rare and accounts for only 1% of jaw cysts reported. Because of its diverse histopathology, there has always been confusion about its nature as a cyst, neoplasm or hamartoma. Several subclassifications have been proposed. Here, we present a case of calcifying odontogenic cyst with ameloblastic proliferation - an extremely rare histologic variant. The classical histologic features of the lining epithelium in the form of cords and presence of characteristic ghost cells were seen along with ameloblastomatous proliferations. Ameloblastomatous COC microscopically resembles unicystic ameloblastoma except for the ghost cells and calcifications within the proliferative epithelium. The nature of the COC is controversial. The case is presented here for its rarity, and difference between ameloblastomatous COC and ameloblastoma ex COC has been emphasized.     

The histologic similarity between craniopharyngioma and odontogenic lesions: a reappraisal

The histologic similarities between the craniopharyngioma and the ameloblastoma are well recognized and supported by their common embryologic origin from oral ectoderm. Differences in these lesions include a greater tendency for craniopharyngiomas to be cystic and form ghost cells and calcifications. The keratinizing and calcifying odontogenic cyst (KCOC), a lesion that features proliferating ameloblastic epithelium, ghost keratin, calcification, and cyst formation, may more precisely mimic the craniopharyngioma. The histologic features of twenty-seven craniopharyngiomas were studied. Twenty cases resembled KCOC microscopically. Two examples duplicated the histologic features of infiltrative ameloblastoma, while five showed characteristics of both lesions. This study shows that the range of histologic features in craniopharyngioma includes and spans both odontogenic lesions but more often simulates KCOC. The results suggest that the KCOC and the ameloblastoma may be closely related developmentally.     

Ameloblastic carcinoma of the jaws: A report of two cases

Two cases of ameloblastic carcinoma of the jaws are reported. Histopathologically, the lesions showed cytologic features of malignancy in addition to classical ameloblastoma patterns and were therefore documented as examples of ameloblastic carcinoma. The negative cytokeratin expression by the malignant cells on histochemical analysis is notably different from that normally observed in classical ameloblastomas.     

Ameloblastic carcinoma of the mandible resembling odontogenic cyst in a panoramic radiograph

Ameloblastic carcinoma is a rare odontogenic tumor exhibiting histologic evidence of malignancy in the primary or recurrent tumor, regardless of whether it has metastasized or not. Most ameloblastic carcinomas are presumed to have arisen de novo, with few cases of malignant transformation of ameloblastoma being apparent. A case is reported of a 21-year-old caucasian female with ameloblastic carcinoma in the left angulus area of the mandible resembling an odontogenic cyst in the panoramic radiograph. In addition to the panoramic radiograph, computerized tomography (CT) and magnetic resonance (MR) images were taken preoperatively. This report demonstrates that CT or MR examinations may be crucial in differentiating odontogenic tumors from cysts.     

Ameloblastic fibro-odontoma: a case report

Ameloblastic fibro-odontoma is a benign epithelial odontogenic tumour with odontogenic mesenchyme exhibiting the histologic characteristics of ameloblastic fibroma and complex odontoma. It is usually associated with developing teeth and occurs predominantly in children and adolescents. In many cases, such lesions are found on radiographic evaluation of patients in whom eruption of teeth is delayed. Ameloblastic fibro-odontoma is generally asymptomatic but may cause swelling and discomfort. This report describes an ameloblastic fibro-odontoma in the posterior mandible of a 26-year-old woman and discusses the histogenesis and clinical features of the lesion.     

Ameloblastic carcinoma. Report of an aggressive case and review of the literature

Odontogenic carcinomas of the jaws are classified as malignant ameloblastoma, ameloblastic carcinoma or primary intraosseous carcinoma. Because these lesions are extremely rare, microscopic diagnosis is difficult. An aggressive case of ameloblastic carcinoma of the mandible is presented. In spite of radical surgery and radiotherapy, the patient expired eight months following initial diagnosis. - A review of the literature seems to indicate that so called simple ameloblastomas rarely can dedifferentiate and metastasize following multiple inadequate surgical procedures. Although radical surgery is not necessary, local excision should be thorough. - Ameloblastic carcinoma and primary intraosseous carcinomas may be histogenetically similar. They are highly malignant tumours which should be treated aggressively. Metastasis is common and prognosis is poor.     

Ameloblastic carcinoma of the jaws. A report of three Nigerian cases.

Ameloblastic carcinoma is an exceptionally rare and aggressive orofacial neoplasm that belongs to a family of malignant epithelial odontogenic tumours. The aetiology remains largely unknown, however most cases are presumed to have arisen de novo, with few of them presenting following malignant transformation of ameloblastoma. We report our experience with three rare cases of ameloblastic carcinoma seen in Nigerians. This is an addition to the sparse literature and to our knowledge; there has been no such report from sub-Saharan Africa.