Adenomatoid dentinoma. Report of four cases of an unusual odontogenic lesion

Diagnostic Enigma of Adenoid Ameloblastoma: Literature Review Based Evidence to Consider It as a New Sub Type of Ameloblastoma

Adenoid ameloblastoma is a hybrid odontogenic tumour showing histopathological features of both ameloblastoma and adenomatoid odontogenic tumour (AOT), with approximately 40 cases reported in the literature. The aims of the report are to illustrate the diagnostic challenges of adenoid ameloblastoma using three new cases and to analyze evidence in literature to consider adenoid ameloblastoma as a new sub type of ameloblastoma. A literature review was performed with the key words-adenoid ameloblastoma, hybrid/composite odontogenic tumours, hybrid ameloblastoma and adenomatoid odontogenic tumour, ameloblastoma with inductive changes, dentinoid and dentinoma to select the cases compatible with the diagnosis of adenoid ameloblastoma. Out of the 40 cases reported in literature, 31 cases with sufficient information and 3 new cases were analyzed. Out of the 34 adenoid ameloblastomas majority of tumours (76.5%) occurred in adults with age ranging from 25 to 55 years. Slight female predilection with a male:female ratio of 0.9:1 was observed. Approximately, 64.7% occurred in the mandible. Radiologically, 82.4% of adenoid ameloblastomas presented as radiolucent lesions while 47.1% occurred with ill-defined margins and cortical perforation at diagnosis. Histopathologically, 70.8% of tumours presented as plexiform ameloblastomas, while duct like structures/glandular structures were the commonest feature supportive of adenomatoid odontogenic tumour observed in overwhelming majority of 95.9% of adenoid ameloblastomas. 91.6% of tumours showed inductive change in the form of dentinoid. Further, 45.4% of the tumours developed at least one recurrence following surgical excision. The report presents literature review based evidence to show the existence of adenoid ameloblastoma, which is demographically similar to conventional ameloblastoma but with histopathological differences and presenting with higher rate/multiple recurrences, indicating its biological aggressiveness. Thus, we would like to propose the inclusion of adenoid ameloblastoma as a sub type of ameloblastoma in the next revision of the WHO odontogenic tumour classification.

Odontogenic Carcinoma With Dentinoid in Long-Term Follow-up With 2 Recurrences

Dentinoid has been mentioned as a frequent component in several types of benign odontogenic tumors; however, there are some other very rare dentinoid-producing odontogenic tumors that have been described, which are not recognized in the current World Health Organization Histological Classification of Odontogenic Tumours. In this context, we report an unusual malignant odontogenic tumor containing dentinoid located in the left maxilla of a 41-year-old man. The lesion was initially diagnosed and treated as a cemento-ossifying fibroma. After 7 years, a tumor was noted at the same location and was diagnosed as pleomorphic adenoma. The patient developed a new lesion 2 years later. Histological features included an epithelial proliferation of basaloid and clear cells, some with peripheral palisading, which were scattered both in a fibrous stroma and within an amorphous eosinophilic dentinoid product. Because of doubts about the first 2 diagnoses and the current situation, all histopathological slides were reviewed in our service as a consultation case, and the findings were consistent with the diagnosis of an odontogenic carcinoma with dentinoid. Immunohistochemical analysis was performed and an ultrastructural study by scanning electronic microscopy and energy-dispersive X-ray microanalysis was made to characterize dentinoid material. After 1 year of follow-up, the patient is alive and free of the disease. This case highlights the wide variability regarding cytological evidence of malignancy, and adds a new case of odontogenic carcinoma with dentinoid, which represents a distinct entity with locally aggressive behavior and should be considered be included in a future World Health Organization Histological Classification of Tumours.

Ameloblastoma with adenoid features: A series of eight cases

BACKGROUND

Ameloblastoma with adenoid features are characterized by the presence of duct-like structures formed from the parenchyma of the tumor. This study was conducted to report a series of eight ameloblastomas with adenoid features, highlighting their clinicopathological and immunohistochemical aspects.

MATERIAL AND METHODS

Out of 71 cases of ameloblastomas, this study classified 8 cases as ameloblastomas with adenoid features. Clinicopathological data and immunohistochemistry for CK7, CK14, CK19, IMP3, p53 and Ki-67 were evaluated.

RESULTS

From those cases of ameloblastoma exhibiting adenoid features, there were 4 women and 4 men, with mean age of 39 years. Most cases affected the mandible and all presented radiographically as a radiolucency. The predominant histopathological features were pseudoducts, squamous metaplasia, nuclear hyperchromatism, clear cells, whorled aspect of epithelial structures, cribriform growth pattern, proliferation of spindle cells and extracellular eosinophilic material. Immunohistochemical analysis showed high expression for CK14 (n = 6) and CK19 (n = 3) and all cases (n = 8) were negative for p53, IMP3 and CK7. In addition, all samples (n = 8) showed low expression for Ki-67.

CONCLUSIONS

The similarities between the histopathological and immunohistochemical features of eight cases described in the present study and those described in previous studies support the possibility that these lesions are adenoid ameloblastomas. In addition, the immunohistochemical results of CK14, CK19, p53 and Ki-67 did not differ from those of conventional ameloblastomas.

A rare case report of an adenomatoid odontogenic tumor associated with odontoma in the maxilla

INTRODUCTION

The adenomatoid odontogenic tumor (AOT) associated with odontoma has been described as a new entity with overlapping features of adenomatoid-like structures and odontoma. Presentation of the case: We report the second case of AOT associated with odontoma in the posterior maxillary region. A 22-year-old patient presented expansion of the vestibular and palatine cortical wall of maxilla. Radiographic examination and computed tomography confirmed erosion of maxillary walls, root resorption, displacement of a neighboring tooth and radiopacities within the lesion. Histopathological analysis showed a cystic cavity lined by odontogenic epithelium, organized as duct like structures and tubular dentin. The diagnosis established was AOT associated with odontoma.

DISCUSSION

As fewer cases have been described, the aim of this study is to report clinical behavior and evolution of adenomatoid odontogenic tumor associated with odontoma, as it have not yet been described and its origin is not completely established. The hamartomatous or neoplastic origin of this tumor is under debate.

CONCLUSIONS

Therefore, it is necessary similar cases to be published to increase the knowledge about the clinical behavior and evolution of this tumor, to enable such lesions to be more clearly defined in the next classification of odontogenic tumors.

Adenoid ameloblastoma with dentinoid: A rare hybrid variant

Odontogenic tumors comprise an unusual group of lesions of the jaw and present diverse histological patterns. Derived from the primordial tooth-forming tissues, they represent a heterogeneous group of lesions that range from hamartomas to benign and malignant neoplasms of variable aggressiveness. Sporadic case reports and diverse complex histogenetic source also defy categorization of odontogenic tumors. Many can be diagnosed accurately based on the distinctive clinical, radiological and histopathological presentation. Considerable variations in the clinicopathological presentation of odontogenic tumors can be confusing, increasing the chance of misdiagnosis. An interesting case of adenoid ameloblastoma reported in a 55-year-old male patient in the mandible, presenting with a diverse and intriguing histopathology, is discussed here.

Adenoid ameloblastoma: clinicopathologic description of five cases and systematic review of the current knowledge

OBJECTIVE

To describe the clinicopathologic and immunohistochemical features of five cases of adenoid ameloblastoma.

STUDY DESIGN

Clinicopathologic data were gathered from medical records and compared with those compiled from a systematic review. Slides were also immunohistochemically stained for Ki-67, p16, p53, and cytokeratins (7, 8, 14, 18, and 19).

RESULTS

There were 3 males (60%) and 2 (40%) females. The mean age was 44 ± 10 years. Of the five adenoid ameloblastomas, 4 (80%) occurred in the posterior maxilla. Patients typically complained of asymptomatic swelling. All patients received surgical resection as primary therapy; 1 (20%) patient also received adjuvant radiotherapy. Recurrence was diagnosed in all patients. Immunohistochemically, the tumors stained focally positive for CK7, 8, 14, and 18 and diffusely positive for CK-19, p16, and p53. The mean Ki-67-positive cells were 72.4 ± 24.9 positive cells per high-power field (range 53-111).

CONCLUSIONS

To our knowledge, this is the largest series of adenoid ameloblastoma reported in the literature. Our data suggest that this entity demonstrates aggressive behavior characterized by a high likelihood of recurrence.

Odontogenic carcinoma with dentinoid: a new odontogenic carcinoma

Dentinoid is an integral part of some odontogenic tumors. This article describes the clinico-pathological features of three cases of odontogenic carcinomas with dentinoid (OCD). A comparison of these with previously reported cases of dentinoid-producing epithelial odontogenic tumors allowed us to identify another six cases that may be considered as examples of OCD. Six cases occurred in the mandible and three in the maxilla, all developing behind the canines. There was no sex predilection (five men and four women; age range 14-61 years, mean 38.1). Pain or discomfort was mentioned in five cases, four of which showed tooth resorption. All cases appeared initially as well-defined radiolucencies, five of which showed variable amounts of calcified material. Recurrences were recorded in three instances, but no evidence of metastasis has been found. Seven cases were composed predominantly or entirely of clear cells, usually with minimal cellular atypia and variable mitotic activity; however, in all cases there was evidence of tumor infiltration into adjacent tissues, including the presence of perineural invasion in two tumors. Those cases in which no reference was made to the presence of clear cells exhibited evident mitotic activity and cellular pleomorphism. The epithelium in OCD does not produce buds or enamel organ-like structures such as those found in ameloblastic fibro-dentinoma and this tumor does not contain a mesenchyme-like connective tissue resembling dental papilla as observed in several mixed odontogenic tumors. Based on the existing data and the present series of cases, OCD appears to represent a distinct entity.

Odontogenic tumors, WHO 2005: where do we go from here?

As our knowledge of disease improves, its classification continually evolves. The last WHO classification of odontogenic tumors was 9 years ago and it is time for revision. We offer the following critique as a constructive, thought provoking challenge to those chosen to provide contemporary insight into the next WHO classification of odontogenic cysts, tumors, and allied conditions.

Adenomatoid odontogenic tumor associated with odontoma: a case report and critical review of the literature

We describe a case of adenomatoid odontogenic tumor (AOT) associated with odontoma occurring in the posterior mandible of a 32-year-old man. Although calcifications are commonly found in the AOT, the presence of rudimentary dental structures is a very rare phenomenon. Cases with similar aspects have been described as ameloblastic dentinoma, ameloblastic odontoma, adenoameloblastic odontoma and AOT associated with odontoma. After a careful analysis of the literature we describe the clinical aspects of this tumor. Further case reports and surveys of odontogenic tumors are necessary to define whether AOT associated with odontoma is a variant of AOT or a distinct clinicopathologic condition.

Bilateral adenomatoid odontogenic tumour of the maxilla in a 2-year-old female--the report of a rare case and review of the literature

Multifocal odontogenic lesions are uncommon and have only been observed in conditions associated with known genetic mutations. To the best of our knowledge, only two cases of multifocal adenomatoid odontogenic tumours (AOT) have previously been reported in the literature. In this study, we report the first case of a bilateral, separate AOT in the maxilla in the midline in a 2-year-old female. The patient presented with bilateral expansile masses in the maxilla on either side of the midline which had been present for 6 months. She was asymptomatic and had occasional difficulty in breathing. The tumour was diagnosed as AOT and was surgically enucleated along with the associated teeth. The patient recovered well and has been on recall for 5 years. The follow-up panoramic radiograph made a fortnight ago revealed evidence of three new radio-opaque lesions with an associated tooth in the region of the anterior mandible, the premolar region of the right maxilla and the molar region of the left maxilla. To acquire additional information about AOT, all reports regarding AOT cited in 'PubMed' from 1995 onward were reviewed and the incidence, clinical features, radiographic features and management of AOT are discussed in this study.

Adenomatoid odontogenic tumor concomitant with cystic complex odontoma: case report

This case report describes a 10-year-old female patient with an adenomatoid odontogenic tumor developing together with a cystic complex odontoma. This occurrence is considered very unusual. Immunohistochemical detection of cytokeratins AE1/AE3, CK5, CK8, CK10, CK14, CK19 and Ki-67 was performed.

Bilateral adenomatoid odontogenic hamartoma

We report the first case of bilateral odontogenic lesions consistent with several cases of unifocal adenomatoid odontogenic hamartoma in the literature. The lesions were well circumscribed, unilocular, radiolucent, and located in the region of the third mandibular molar region in a 12-year-old female patient. The lesions were composed of odontogenic hard and soft tissues, dental papilla, dentin, enamel matrix, and adenomatoidlike odontogenic epithelium. The lesions were enucleated with no recurrence at 6 months.

Adenomatoid odontogenic tumor (AOT) originating in a unicystic ameloblastoma: a case report

The follicular variant of the adenomatoid odontogenic tumor (AOT) is thought to originate from the reduced enamel epithelium of the dental follicle. The origin of the extra-follicular variant however, remains less clear. This paper presents a case of an extra-follicular AOT, which we believe originated from the epithelial lining of a unicystic ameloblastoma, and reviews the literature. The available evidence seems to indicate that some extra-follicular AOTs might arise as secondary phenomena within pre-existing odontogenic cysts or cystic tumors.

An updated clinical and epidemiological profile of the adenomatoid odontogenic tumour: a collaborative retrospective study

BACKGROUND

Adenomatoid odontogenic tumour (AOT) is a benign odontogenic jaw lesion. The aim of this study was to update the biological profile of AOT.

MATERIAL AND METHODS

Cases published in the literature and cases in files of co-authors were included.

RESULTS

550 new cases were retrieved, and of a total of 1082 cases analysed, 87.2% were found in the second and third decades. The M:F ratio was 1:1.9. 70.8% were of the follicular variant (extrafollicular: 26.9%, peripheral: 2.3%). 64.3% occurred in the maxilla. 60% of follicular AOTs were associated with unerupted canines. Nineteen cases of AOT (2.8%, M:F ratio was 1:1.4) were associated with embedded third molars. Twenty-two peripheral AOTs (2.3%, M:F ratio was 1:5.3) were recorded. The relative frequency (RF) of AOT ranged between 0.6% and 38.5%, revealing a considerably wider AOT/RF range than hitherto reported (2.2-7.1%).

CONCLUSIONS

This updated review based on the largest number of AOT cases ever presented, confirms the distinctive, although not pathognomonic clinicopathological profile of the AOT, its worldwide occurrence, and its consistently benign behaviour.

Adenomatoid dentinoma or adenomatoid odontogenic hamartoma: what is the better term to denominate this uncommon odontogenic lesion?

We report two cases of an uncommon odontogenic lesion, previously described as adenomatoid dentinoma. They were well-circumscribed unilocular radiolucent lesions exhibiting discrete radiopacities, located in the left mandibular third molar region. Microscopically they were composed of odontogenic hard and soft tissues, similar to a dental germ. Dental papilla and dentin were easily identified. Odontogenic epithelium formed adenomatoid-like structures, and by scanning electron microscopy a layer of enamel was seen in contact with the dentin. Based on these clinical, radiographic, histological and electron microscopical features we proposed the diagnosis of adenomatoid odontogenic hamartoma. Treatment consisted of surgical removal, and no recurrence was observed. In our opinion all similar cases previously reported pertain to the same spectrum of this lesion and thus should be named as suggested above. Moreover, ultrastructural observations using 5 microm sections can be useful to better characterize the presence of hard tissues.

Adenoid ameloblastoma with dentinoid: a case report

A man had a lesion of the anterior mandible that was initially diagnosed at 39 years of age as an adenomatoid odontogenic tumor. The lesion recurred 3 times over a span of 16 years. A consultative review of all histological findings was done and the tumor was reclassified as an ameloblastoma.