Characterization of stromal calcifications in odontogenic keratocyst: a multicentric study.

Odontogenic keratocysts (OKCs) are locally aggressive cysts that exhibit typical histopathological features and have a propensity for recurrence. Though histological variations are observed in OKCs, hard tissue formation and metaplastic changes are rare, and the underlying pathogenesis is not well understood. This study aimed to characterize stromal calcifications and analyze their association with odontogenic components in non-syndromic and syndrome-associated cases of OKCs. We analyzed 153 cases of OKCs from healthcare institutes in India and Japan. The epithelial and stromal features were evaluated, and the relationship of calcifications with odontogenic rests was determined. Immunohistochemistry for cytokeratin-19 and special stains including Masson Trichrome and Van Gieson, were used for identification of odontogenic rests and calcifications respectively. Stromal calcifications were observed in 29.41% OKCs. The calcification patterns included irregular dystrophic, dentinoid with linear or calcospherite-type mineralization, and psammoma calcifications. Psammoma and dentinoid calcifications were found in the proximity of cytokeratin-19-positive odontogenic rests or satellite cysts, whereas majority cases with dystrophic calcifications did not exhibit co-localization with stromal odontogenic components. Distinct patterns of calcifications were observed in OKCs. Calcifications found in proximity of the odontogenic rests were possibly indicative of an inductive or host-mediated response.

Odontogenic carcinoma with dentinoid: case report and literature review of a rare entity.

BACKGROUND: Odontogenic carcinoma with dentinoid (OCD) is a rare and controversial entity, which has not yet been included in the current World Health Organization classification of odontogenic lesions. Owing to the small number of reported cases, the clinicopathological characteristics, biological behavior, prognosis, and appropriate treatment strategies for OCD remain to be defined. Herein, we present an additional case of OCD with a focus on the differential diagnosis and review of the pertinent literature, in order to enable better recognition by oral clinicians and pathologists and further characterization of this entity. CASE PRESENTATION: This paper reports a case of OCD in the posterior mandible of a 22-year-old female. Radiography showed a well-defined unilocular radiolucency with radiopaque materials. The intraoperative frozen section pathology gave a non-committed diagnosis of odontogenic neoplasm with uncertain malignant potential. Then a partial mandibulectomy with free iliac crest bone graft and titanium implants was performed. Microscopically, the tumor consisted of sheets, islands, and cords of round to polygonal epithelial cells associated with an abundant dentinoid matrix. Immunohistochemically, the tumor cells were diffusely positive for CK19, p63, and ß-catenin (cytoplasmic and nuclear). No rearrangement of the EWSR1 gene was detected. The final diagnosis was OCD. There has been no evidence of recurrence or metastasis for 58 months after surgery. We also provide a literature review of OCD cases, including one case previously reported as ghost cell odontogenic carcinoma from our hospital. CONCLUSIONS: OCD is a locally aggressive low grade malignancy without apparent metastatic potential. Wide surgical excision with clear margins and long-term period follow-up to identify any possible recurrence or metastases are recommended. Histopathological examination is essential to conclude the diagnosis. Special care must be taken to distinguish OCD from ghost cell odontogenic carcinoma and clear cell odontogenic carcinoma, as misdiagnosis might lead to unnecessary overtreatment. Study of additional cases is required to further characterize the clinicopathological features and clarify the nosologic status and biological behavior of this tumor.

The evolving molecular characterisation, histological criteria and nomenclature of adenoid ameloblastoma as a World Health Organisation tumour type.

Adenoid ameloblastoma (AA) was recently recognised as a separate tumour type in the most recent World Health Organisation (WHO) classification of head and neck tumours. This decision has been considered controversial by several groups, who have described AA as a subtype of ameloblastoma, a hybrid odontogenic tumour or to fall within the spectrum of other recognised odontogenic tumours, including dentinogenic ghost cell tumour and adenomatoid odontogenic tumour. Here we review the reasons for the WHO decision to classify AA as a separate tumour type. We also critique molecular and histological findings from recent reports published since the WHO classification. While acknowledging that the classification of tumours is constantly evolving, the balance of current evidence suggests that AA should remain a distinct tumour type, and not a subtype of ameloblastoma, pending further molecular characterisation.

ß-catenin nuclear translocation and WNT pathway mutations in ghost cell odontogenic carcinoma: A literature review and proposal of a new molecular-based classification "WNT pathway-altered malignant odontogenic tumor".

Ghost cell odontogenic carcinoma (GCOC) is defined as a rare type of odontogenic carcinoma that is characterized by ghost cells and occasional dentinoid. However, the current classification system based primarily on the presence of ghost cells has limitations in the diagnosis of GCOC and its histologic mimics including odontogenic carcinoma with dentinoid (OCD). This study reviewed previous studies on ß-catenin nuclear translocation and WNT pathway mutations in GCOC and OCD and discussed the potential utility of a new molecular-based classification "WNT pathway-altered malignant odontogenic tumor" for these rare odontogenic tumors.

A Systematic Review of Adenoid Ameloblastoma: A Newly Recognized Entity.

BACKGROUND: Recently, a new odontogenic tumor has been described, the so-called adenoid ameloblastoma (AdAM). The aim of this review was to determine the clinical and imaging features of AdAM and to describe its main histopathological findings. METHODS: The systematic review included published cases with a diagnosis of AdAM in the gnathic bones, which had sufficient clinical, imaging, and histopathological data to confirm its diagnosis. The following histopathological diagnostic criteria were adopted: presence of ameloblastoma-like components, duct-like structures, spiral cellular condensations, and a cribriform architecture. RESULTS: Fifteen articles, corresponding to 30 cases of AdAM, were selected. Most cases affected men (63.3%), with a slight preference for the mandible (16:14) and the posterior region of gnathic bones was the most commonly affected site. The mean age at diagnosis was 40.8 years. Clinically, the lesions usually presented as a swelling (53.3%) and, radiographically, as a well-defined radiolucency (33.4%). Surgical resection (40%) was the most frequently adopted treatment and recurrence occurred in 30% of cases. Microscopic examination showed cribriform areas in most AdAM cases (93.3%); duct-like structures and spiral cellular condensations were seen in 100% of the cases. CONCLUSION: The small number of reported cases, the existence of erroneous diagnoses, and the adoption of initial conservative management make it difficult to determine whether AdAM has a higher risk of recurrence or more aggressive biological behavior than conventional ameloblastomas.

Demystifying Histologic Conundrum of Adenoid Ameloblastoma: Case Report with Literature Review.

Introduction: Odontogenic tumors encompass a heterogeneous group of lesions that range from hamartomatous lesions to malignancy. Considerable variation in histologic presentation can mislead their accurate diagnosis and categorization. Ameloblastoma is generally well understood and is easy to diagnose but there has been a constant change in the classification systems ever since Broca classified odontogenic tumors in the year 1867. Over the years, it has been modified by the World Health Organization with many additions and omissions. This dynamic change is based on the result and conclusions of molecular and genetic studies with the last modification in 2017. Case Report: We present two cases of females aged 32 and 60 years who reported with facial swellings, revealed the presence of distinct histopathological findings and were diagnosed as ameloblastoma with dentinoid or adenoid ameloblastoma. Literature search revealed dearth of distinct forms of ameloblastoma that show the formation of duct like structures and dentinoid. Conclusion: It is interesting to highlight such cases as the biological behavior is still unexplored due to paucity of relevant studies and follow up of patients. Understanding the pathogenesis and the histopathological characteristics of the newer entities will enable the prompt diagnosis, treatment plan and expanding the spectrum of the lesions. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-03534-6.

Adenomatoid odontogenic tumor: Features of ameloblastic-like epithelial cells differentiation, secretion, and the nature of tumor cells products.

BACKGROUND: This study aimed to investigate the differentiation of ameloblastic-like cells and the nature of the secreted eosinophilic materials in adenomatoid odontogenic tumors. METHODS: We studied histological and immunohistochemical characteristics of 20 cases using: cytokeratins 14 and 19, amelogenin, collagen I, laminin, vimentin, and CD34. RESULTS: Rosette cells differentiated into ameloblastic-like cells positioned face-to-face, displaying collagen I-positive material between them. Epithelial cells of the rosettes can differentiate into ameloblastic-like cells. This phenomenon probably occurs due to an induction phenomenon between these cells. The secretion of collagen I is probably a brief event. Amelogenin-positive areas were interspersed by epithelial cells in the lace-like areas, outside the rosettes and distant from the ameloblastic-like cells. CONCLUSIONS: There are at least two types of eosinophilic material in different areas within the tumor, one in the rosette and solid areas and another in lace-like areas. The secreted eosinophilic material in the rosettes and solid areas is probably a product of well-differentiated ameloblastic-like cells. It is positive for collagen I and negative for amelogenin, whereas some eosinophilic materials in the lace-like areas are positive for amelogenin. We hypothesize that the latter eosinophilic material could be a product of odontogenic cuboidal epithelial or intermediate stratum-like epithelial cells.

Calcifying odontogenic cyst associated with compound odontoma - A rare entity.

Calcifying odontogenic cyst (COC) or Gorlin's cyst categorized as a distinct entity by Gorlin et al. in 1962. It is a rare benign developmental cystic lesion that accounts for less than 1% of all odontogenic cysts. It can occur in association with various types of odontogenic tumors such as odontomas. COC is a hybrid lesion of the jaw presenting a manifold variety of clinical behaviors and histopathological characteristics including cystic, solid (neoplastic), and aggressive forms. COC exhibits diversity in terms of its clinical presentations, histopathologic features, and biological behavior. Normally, it presents as asymptomatic, slow developing lesion affecting the maxilla and mandible equally with strong predilection for the anterior segment. Radiographically, these lesions usually present as a unilocular, well-defined radiolucency with radiopaque structures within the lesion, either as irregular calcifications or tooth-like densities. The distinct features of COC as solid or cystic lesions presents with an ameloblastomous component admixed with varying proportions of ghost cells and spherical calcifications. Here, we report an article of calcifying odontogenic cyst associated with compound odontoma in a young patient with lesion in the anterior mandible with review of the various terminologies and classification and histopathology.

Dentinogenic ghost cell tumor: a case report and review of the literature.

The purpose of this report is to highlight the presentation and review the clinical and histopathological features of DGCT. There have been 130 DCGT diagnoses reported in the literature. DGCT is part of the odontogenic ghost cell tumor family which also includes the calcifying odontogenic cyst (COC) and the ghost cell odontogenic carcinoma (GCOC). In June of 2018, a 48-year-old female presented with a painless, soft tissue growth overlying the right mandibular alveolar ridge. Further workup of the lesion included a panoramic radiograph and maxillofacial computed tomography (CT) which revealed a well-defined, multilocular lytic expansile radiolucency occupying the right mandibular body. An incisional biopsy of the right mandibular gingival mass was performed which revealed an unusual odontogenic neoplasm with mineralization and ghost cells. The patient was subsequently treated with excisional biopsy of the right mandibular lesion via enucleation and curettage. The specimen was sent to pathology and the tumor was found to have an epithelial neoplastic proliferation resembling that of ameloblastoma, accompanied by foci of ghost cells. Since mandibular bone was involved, a diagnosis of a benign central DGCT with extension into the overlying gingiva was rendered. She was successfully treated with excisional biopsy via enucleation and curettage and has no evidence of recurrence at three years post-operatively. DGCT can exhibit locally aggressive behavior and is characterized by ameloblastoma-like epithelial cells and the presence of dentinoid material and ghost cells.

Ameloblastic fibroma with extensive dentinoid - A rare presentation.

Ameloblastic fibroma (AF) is a rare benign odontogenic tumour first described by Kruse in 1891. Although reported in a wide age range, most of the cases are seen in the first two decades of life with majority of cases being diagnosed before the age of 20 years. There are reported variations in the histopathological presentation of ameloblastic fibroma. In this case report, we present a case of ameloblastic fibroma with extensive dentinoid formation involving the mandible in an 8-year-old male patient which clinically presented as an aggressive lesion.

Incidental finding of orthokeratinized odontogenic cyst with unusual features.

Orthokeratinized odontogenic cyst (OOC) is a rare developmental odontogenic cyst occurring in the jaw with debated etiology. It was originally believed to be a variant of odontogenic keratocyst (OKC) but is now considered to be a distinct entity. The majority of the cases occur in the third and fourth decades of life. The common site is the mandibular posterior region with a male predilection. Swelling is the most common symptom which may be accompanied by pain, although in most cases, the lesion is asymptomatic. These lesions mostly present as unilocular radiolucency often associated with an impacted tooth. They may mimic dentigerous cyst and OKC in radiologic and histopathologic presentation, however, differ in biological behavior, pathogenesis and prognosis in comparison. Hence, making an accurate diagnosis is essential. This article describes an incidental finding of OOC in a 28-year-old female during radiographic investigation for orthodontic treatment. This case showed some rare features such as multilocular radiolucency, nonkeratinized epithelium in areas of inflammation, few cholesterol clefts with giant cells, presence of dentinoid-like material and dystrophic calcification in the capsule.

Clear Cell Odontogenic Carcinoma: A Series of Three Cases.

BACKGROUND: Clear cell odontogenic carcinoma (CCOC) is a rare malignant odontogenic epithelial neoplasm of the jaws. It is composed of irregular nests of clear to faintly eosinophilic cells resembling clear cell rests of primitive dental lamina and an intermixed hyalinized fibrous stroma. Most cases occur in the 5th and 6th decades of life, with a female predominance. The mandible is affected more than the maxilla. Clinical features vary from asymptomatic to non-specific pain, ill-defined radiolucency, root resorption, and sometimes soft tissue extension. Histology varies from bland to high grade. CCOC demonstrated a significant tendency to recur. Metastasis typically involves regional lymph nodes, which haves been reported in 20-25% of cases. Pulmonary metastasis rarely occurs. Differential diagnoses are broad and include odontogenic, salivary, melanocytic, and metastatic neoplasia. CCOCs are positive for cytokeratins, mainly AE1/AE3 and CK19. Most cases show EWSR1 rearrangement and rarely, the BRAFV600E mutation. DESIGN: Patient charts were reviewed at our institution. A total of three cases were found in electronic medical records, which were diagnosed as clear cell odontogenic carcinoma over a period of six years (2014-2019). Patient charts were reviewed for medical history and radiology data. The pathology slides were reviewed by one or more faculty members. RESULTS: We present three cases of CCOC, ranging in age from 40 to 69 years (two women and one man). Two cases involved the maxilla and one involved the mandible. Two presented with painful swelling and one with mass recurrence. Radiography results show that two had poorly defined radiolucent lesions, and one was heterogeneous with a small nodule projecting into the maxillary sinus. Histological examination revealed an epithelial neoplasm composed of irregular sheets, cords, and nests of polygonal cells with central hyperchromatic, mildly pleomorphic nuclei surrounded by clear to pale eosinophilic cytoplasm, with occasional mitotic figures. The tumor had infiltrated the bone and soft tissues. Two cases were immunopositive for CK5/6 and one case was positive for p63 and CK19. Interestingly, the eosinophilic dentinoid matrix interspersed among tumor cells in one case was consistent with its odontogenic origin. Histochemical staining showed PAS-positive and diastase-labile intracytoplasmic material consistent with glycogen. CONCLUSION: Our study highlights the potential diagnostic significance of dentinoid (although reportedly seen in only 7% of cases), along with CK5/6 immunopositivity, in supporting the histologic diagnosis of CCOC among a variety of neoplasia in its differential diagnosis.

Odontogenic carcinosarcoma with dentinoid: a rare case report.

Odontogenic carcinosarcoma is a very rare malignant odontogenic tumor, characterized by malignant epithelial and mesenchymal components. Studies have reported several cases of odontogenic carcinosarcoma, mainly in the upper and lower jaws, with malignant clinical manifestations. Herein, we present the case of a 58-year-old woman with odontogenic carcinosarcoma with dentinoid in the left maxilla. The invasion range was large, and the left maxillary molar was missing. Histology revealed odontogenic carcinosarcoma with bidirectional differentiation characteristics and comprising three components: malignant epithelium, malignant interstitium, and dentinoid. The patient subsequently underwent nasal endoscopic sinus tumor resection, and she recovered well after surgery. After a strict 4-year follow-up, to date, there are still no signs of disease or local recurrence. To our knowledge, this is the first reported case of odontogenic carcinosarcoma with dentinoid. Our study describes the clinical, morphological, and immunohistochemical characteristics of this case, and distinguishes it from related diseases.

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.

Clinico-Pathological Presentations of Cystic and Classic Adenomatoid Odontogenic Tumors.

The objective of the study is to present the clinico-pathological features of cystic and classic adenomatoid odontogenic tumors (AOTs) in order to identify the differences between the two variants of AOT. MATERIALS AND METHOD: The study sample comprised of 41 AOTs, which were categorized into cystic and classic AOTs. Cystic AOTs are diagnosed as such when macroscopic and microscopic evidence of a cyst is present together with histopathological criteria of AOT (WHO-2017). RESULTS: The study sample comprised of eleven cystic and thirty classic AOTs. Eight cystic AOTs were regarded as arising from dentigerous cysts as these lesions were attached to the cemento-enamel junction of the impacted teeth. Though not statistically significant, in contrast to classic AOTs which showed female predilection, cystic AOTs were more prevalent in males. Cystic AOTs tend to present as significantly larger lesions compared to classic AOTs (p < 0.02). In both cystic and classic AOTs, duct-like structures and epithelial whorls were the two most prominent histopathological features present in the majority of tumors. Two AOTs with massive amounts of dentinoid occurred in the mandible and presented as large lesions that eroded cortical bone. None of the 12 patients with follow-up information presented with recurrences. CONCLUSION: Except for the size of the lesion, no significant clinico-pathological differences were observed between cystic and classic AOTs. Therefore the cystic AOTs can be considered as a variant of AOT with enucleation, simple excision, or radical excision as the treatment of choice depending on the extent of the lesion, similar to classic AOTs.

Dentinogenic ghost cell tumor: A case report.

BACKGROUND: Dentinogenic ghost cell tumor (DGCT) is an uncommon locally invasive odontogenic neoplasm. It is considered to be a solid variant of calcifying odontogenic cyst (COC). This tumor makes up for only 2%-14% of all COCs and less than 0.5% of all odontogenic tumors which owes to its rarity. The purpose of this paper was to describe a case of DGCT and the treatment adopted in our case, and to provide a review of this case in the indexed literature. CASE SUMMARY: In this article, we discussed a case of 18 year old male who reported with a chief complaint of a recurrent swelling and dull aching pain in upper left back region of the jaw. Computed tomography scan was carried out which revealed hypodense lesion with a few hyperdense flecks within it suggesting the presence of calcification. On incisional biopsy, diagnosis of COC was given. After segmental resection of the lesion, histopathogically odontogenic epithelium was noted along with calcifications, ghost cells and dentinoid material. Special staining was done with van Gieson and it showed pink areas of dentinoid material and yellow colour represented ghost cells. Hence, amalgamation of careful clinical examination, use of advanced radiographic imaging and detailed histopathological examination confirmed the diagnosis of DGCT. The patient was followed up for one year and there was no recurrence of the lesion or signs of any residual tumor. CONCLUSION: Radical treatment should be carried out along with mandatory long-term follow up in order to avoid recurrence in aggressive lesions.

Dentinogenic ghost-cell tumor of the maxilla: A case report and review of literature.

Dentinogenic ghost-cell tumor (DGCT) is a rare, odontogenic neoplasm which is considered to be a solid variant of the calcifying odontogenic cyst (COC) with locally aggressive behavior and is characterized by ameloblastoma-like epithelial islands, ghost cells and dentinoid. It accounts for only 2%-14% of all COCs. Herewith, we report the case of DGCT in a 40-year-old male patient with clinical presentation as swelling on the right side of the face.

Ameloblastic Fibrodentinoma: A Case with Varied Patterns of Dysplastic Dentin.

Ameloblastic fibrodentinoma is a benign odontogenic tumor belonging to the category of "odontogenic epithelium with odontogenic ectomesenchyme" along with recognition of induction in the form of dentin in atypical or dysplastic forms. The biological behaviour of ameloblastic fibrodentinoma is not very different from ameloblastic fibroma; hence, it is treated similarly by conservative procedures. It is important to understand the histopathogenesis of these rare tumors. Though rare, they are an independent entity awaiting recognition. Here, we report a case of amelobalstic fibrodentinoma in a 14-year-old female patient.

Dentinogenic ghost cell tumor.

Dentinogenic ghost cell tumor (DGCT) is a rare, odontogenic neoplasm which is considered to be a solid variant of calcifying odontogenic cyst (COC) with locally aggressive behavior. It accounts for only 2-14% of all COCs. To the best of our knowledge, only 88 cases of DGCT have been reported in the literature from 1968 to 2014. Herewith, we report a case of DGCT in a 68-year-old male patient with clinical presentation as a soft tissue growth over alveolar ridge and histopathologically characterized by ameloblastomatous epithelium, abundance of eosinophilic material and ghost cells.

Primordial Odontogenic Cyst with Induction Phenomenon (Zonal Fibroblastic Hypercellularity) and Dentinoid Material Versus Archegonous Cystic Odontoma: You Choose!

The most recent A.F.I.P. fascicle defines primordial odontogenic cyst (POC) as a distinct, nonkeratinized, odontogenic cyst of "undetermined origin" forming in the place of a developing normal or supernumerary tooth. However, the majority of examples reported in the literature under this term represent odontogenic keratocysts (keratocystic odontogenic tumors). In addition, there are rare reported cases of cystic odontomas. An 18-year-old Caucasian male presented with a unilocular mandibular radiolucent lesion in the place of a congenitally missing molar. Histologically, it featured nonkeratinizing, thin stratified squamous epithelial lining with areas of spongiosis and foci of vacuolization of individual basal cells without significant nuclear palisading. Focally, budding of the basal cell layer was identified. A zone of increased cellularity featuring induction-type fibroblasts was present subepithelially as well as dentinoid deposits with odontogenic epithelial nests. Immunohistochemically, the epithelial lining was negative for calretinin and the induction-like zone negative for S100 protein, smooth muscle actin, and CD34. The case was externally reviewed by five oral pathologists who provided various diagnostic interpretations including primordial cyst, odontogenic cyst not otherwise specified (NOS), cyst with ameloblastic changes, and unicystic ameloblastoma. At that time, a final diagnosis of odontogenic cyst NOS was rendered with a comment that it may represent a true example of POC or a cystic odontoma. The lesion has not recurred within a 13 year follow-up period after initial excision. An unusual cystic lesion is presented that may represent a true example of POC with dentinoid formation or an archegonous cystic odontoma.