Odontogenic Fibromyxoma in a Cat: First Confirmed Case in This Species.

An inflammatory gingival mass surrounding resorbing teeth was diagnosed via biopsy in a 9-year-old domestic shorthair cat. A dorsal rim excision was performed to remove the entire mass with associated teeth and bone. Histopathological diagnosis of the en bloc tissue revealed an odontogenic fibromyxoma. Extensive literature review revealed few case reports of companion animals with this neoplasm, and none in a feline patient. This report documents the clinical presentation, diagnostic differentials, surgical therapy, and long-term follow-up of an odontogenic fibromyxoma in a cat.

The expression of cytokeratin in keratocystic odontogenic tumor, orthokeratinized odontogenic cyst, dentigerous cyst, radicular cyst and dermoid cyst.

The epithelial lining of odontogenic keratocysts exhibits either parakeratosis or orthokeratosis. In 2005, the WHO classified odontogenic keratocysts with parakeratosis as keratocystic odontogenic tumors (KCOT). Odontogenic keratocysts with orthokeratosis were not classified as odontogenic tumors, but instead referred to as orthokeratinized odontogenic cysts (OOC). To clarify the difference between these two lesions, we investigated their biological characteristics using immunohistochemical studies for cytokeratins (CK) in KCOT and OOC as well as in dentigerous cysts (DC), radicular cysts (RC) and dermoid cysts (DMC). We examined twenty-five cases of KCOT, fifteen cases each of OOC, DC and RC, and ten cases of DMC. We studied the immunohistochemical expression of CK10, 13, 17 and 19. To evaluate the immunohistochemical staining pattern, we divided the epithelial lining of the lesions into three layers (surface layer: su, spinous layer: sp, basal layer: ba). For CK10, most OOC and DMC specimens of su and sp were positive. For CK13 and 19, most KCOT, DC and RC specimens of su and sp were positive. For CK17, most KCOT specimens of su and sp were positive. The percentages of total CK expression of su and sp, and ba of CK19 differed significantly between the lesions (P < 0.001). These results support the hypothesis that OOC originate from not the odontogenic apparatus, but the oral epithelial component.

Molecular markers of cell adhesion in ameloblastomas. An update.

Ameloblastoma is the most common odontogenic tumor of epithelial origin, and though it is of a benign nature, it frequently infiltrates the bone, has a high rate of recurrence and could potentially become malignant. Cellular adhesion potentially plays an important role in the manifestation of these characteristics and in the tumor biology of ameloblastomas. Losses of cell-cell and extracellular matrix adhesion and cohesion are among the first events that occur in the invasion and growth of tumors of epithelial origin. The present review includes a description of the molecules that are involved in cell adhesion as reported for various types of ameloblastomas and discusses the possible roles of these molecules in the biological behaviors of this odontogenic tumor. Knowledge of the complex mechanisms in which these molecules play a role is critical for the research and discovery of future therapeutic targets.

Expression of odontogenic ameloblast-associated protein, amelotin, ameloblastin, and amelogenin in odontogenic tumors: immunohistochemical analysis and pathogenetic considerations.

Screening for expression of amelogenesis-related proteins represents a powerful molecular approach to characterize odontogenic tumors and investigate their pathogenesis. In this study, we have examined the presence and distribution of odontogenic ameloblast-associated protein (ODAM), amelotin (AMTN), ameloblastin (AMBN), and amelogenin (AMEL) by immunohistochemistry in samples of adenomatoid odontogenic tumor (AOT), calcifying epithelial odontogenic tumor (CEOT), developing odontoma, ameloblastoma, calcifying cystic odontogenic tumor (CCOT), ameloblastic fibroma (AF), myxoma, odontogenic fibroma (OF), and reduced enamel epithelia (REE). Positive results were obtained in those tumors with epithelial component, except for AF, OF, and ameloblastoma. ODAM was found around mineralized structures (dystrophic calcifications) and CEOT's amyloid, whereas AMTN stained the eosinophilic material of AOTs. The CCOT transitory cells to ghost cells were strongly positive with all proteins except AMEL, and the REE as well as odontomas showed immunoexpression for ODAM, AMTN, AMBN, and AMEL similar to those found in normal rat tooth germs. Based on these results, some histopathogenetic theories were formulated.

Arenavirus as a potential etiological agent of odontogenic tumours in humans.

Odontogenic tumors (OT) are considered rare events and their epidemiologic data are scarce and under-estimated in developing countries because there is no systematic collection of clinical features including histological analyses of the tissue samples. Furthermore, there is an underestimation of the disease relevance and affected people are often marginalized in spite of severe functional impairment of aero-digestive tract. Etiology of OT in humans is still unknown and it represents an important therapeutic and diagnostic challenge.Lassa fever is an acute viral haemorrhagic illness caused by Lassa virus, a member of the arenavirus family of viruses. The disease is endemic in the rodent population in West-East Africa. Humans usually become infected with Lassa virus through exposure to the food or household items contaminated with urine or feces of infected rats. It is also reported person-to-person infections. About 80% of people infected by Lassa virus have no symptoms but the virus establishes a life-long persistent infection.The present commentary significance is to start, for the first time ever, a systematic collection of clinical features and tissue sample collection at the St. Mary's Hospital in Lacor (Gulu) North Uganda where the considered pathologies have an important frequency. The systematic collection will allow to corroborate the possible association between arenaviruses infection and pathogenesis of odontogenic tumors in humans.

[Maxillary and mandibular carcinogenesis: research and prospects]. / Tumorogenèse des maxillaires. Recherche et perspective.

Development and growth of odontogenic tumours depend on impairment of numerous genes and molecules. In recent years, most of the genes involved in dental development were identified. This produced a new basis for the study of oral pathology and maxillofacial carcinogenesis. A better understanding of these molecular phenomena should allow to better determine the evolution of such lesions. Research breakthroughs should facilitate the development of new molecular and genetic therapeutic perspectives.

[Benign maxillofacial tumours. Odontogenic tumours]. / Tumoraciones maxilares benignas. tumores odontogénicos.

Regarding the 2004 actualization of the classification of benign odontogenic tumours published by IARC and WHO, we have reviewed our files in order to explain the new parameters established in this actualization. Histologically tree groups can be considered depending on the tissue involved: a) odontogenic epithelium with mature fibrous stroma without odontogenic ectomesenchyme, b) odontogenic epithelium with odontogenic ectomesenchyme, with or without tissue formation, and c) mesenchyme and/or odontogenic ectomesenchyme, with or without odontogenic epithelium. Every tumour appears with clinical features, radiographical and specific epidemiology data to complete the cases, in adittion to recurrences and appropriate surgical resection.

Ortho Keratinized Odontogenic Cyst with Dentinoid Formation.

Orthokeratinized odontogenic keratocyst (OOC) was first identified as orthokeratinized variant of odontogenic keratocyst in 1981 by Wright, due to its different histology and relatively low recurrence rate. Parakeratinized odontogenic cyst is now considered as keratocystic odontogenic tumor (KCOT) owing to its neoplastic nature. Although rare, calcification in the form of dystrophic calcification, dentinoid and cartilage has been reported in KCOT, but calcification in OOC is extremely rare and no case in English literature has been reported so far. Here, we report the first case of OOC with calcification located in the mandible of a 40-year female.

Controversies in Odontogenic Tumours: Review.

Odontogenic tumours are lesions that occur solely within the oral cavity and are so named because of their origin from the odontogenic (i.e. tooth-forming) apparatus. Odontogenic tumours comprise a variety of lesions ranging from non-neoplastic tissue proliferations to benign or malignant neoplasms. However, controversies exist regarding the pathogenesis, categorisation and clinical and histological variations of these tumours. The recent 2017 World Health Organization classification of odontogenic tumours included new entities such as primordial odontogenic tumours, sclerosing odontogenic carcinomas and odontogenic carcinosarcomas, while eliminating several previously included entities like keratocystic odontogenic tumours and calcifying cystic odonogenic tumours. The aim of the present review article was to discuss controversies and recent concepts regarding odontogenic tumours so as to increase understanding of these lesions.

Orthokeratinized Odontogenic Cyst with an Associated Keratocystic Odontogenic Tumor Component and Ghost Cell Keratinization and Calcifications in a Patient with Gardner Syndrome.

Gardner syndrome (GS) is caused by mutations in the APC and besides adenomatous colorectal polyps includes such manifestations as osteomas, epidermoid cysts (ECs) and occasionally multiple pilomatricomas. More than 50 % of ECs in patients with GS exhibit pilomatricoma-like ghost cell keratinization. The latter may be explained by the fact that the development of both GS and pilomatricoma is driven by activation of the Wnt/ß-catenin signaling pathway. A 62-year-old, Caucasian male with history of GS presented with a unilocular, mixed radiopaque/radiolucent mandibular lesion causing divergence and external root resorption of involved teeth. Histopathologically, the lesion was composed of two cystic components, an orthokeratinized odontogenic cyst (OOC) and a smaller one with characteristics of keratocystic odontogenic tumor (KCOT) featuring, focally, ghost cells and an epithelial morule-like structure. Dystrophic calcifications essentially similar to those seen in pilomatricomas were observed in the fibrous connective tissue wall. The KCOT and OOC epithelia revealed strong and diffuse cytokeratin (AE1/AE3) and ß-catenin immunoreactivity. CD10 positive immunostaining was seen in the keratin and superficial spinous cell layers in both OOC and KCOT. The intraepithelial and mural ghost cells showed a cytokeratin (+), ß-catenin and CD10 (-) immunophenotype. The diagnosis of OOC with ghost cell calcifications in association with KCOT was rendered. The patient was lost to follow-up. Although a coincidental co-existence cannot be excluded, ghost cell calcifications mimicking pilomatricoma-like changes in an unusual odontogenic cyst combining OOC and KCOT features as seen in this patient with GS may be explained by the common molecular mechanisms underlying the pathogenesis of cutaneous pilomatricomas and GS.

Recurrent Maxillary Odontogenic Myxoma Following Partial Maxillary Resection and Consecutive Osseous Reconstruction Including Tooth Transplantation.

Odontogenic myxoma (OM) is a rare tumour arising in the jaws. The tumour is purported to be odontogenic in origin due to the frequent localisation of the tumour inside the jaws in close relation to teeth. The aim of this report was to detail the course of a patient who developed OM of the maxilla, underwent adequate ablative surgery and reconstruction, including tooth transplantation to the original tumour site, and subsequently developed a local recurrence in close proximity to the teeth transplanted to the reconstructed maxilla 6 years after the first diagnosis. Once again, a partial maxillary resection was performed, with no reconstruction. The patient has been free from tumour recurrence for over 20 years. We discuss the current hypothesis on OM pathogenesis and the possible impact of actively dividing cells on tumour re-growth.

Odontogenic tumour of lip.

There have been nine cases of ;calcifying epithelial odontogenic tumour' described so far. The histological pattern is quite distinctive, and one feature is the presence of abundant intracytoplasmic and stromal material which (Vickers, Dahlin, and Gorlin, 1965) has been shown to react histochemically as amyloid. The tumour is generally believed to be epithelial in origin, arising from the reduced enamel organ of an unerupted tooth with which all the tumours so far recorded are associated. Another case is described, this time arising in the soft tissue of the lip and remote from a tooth. This tumour showed features which suggest that it is of odontoblastic origin and therefore not epithelial. Evidence is also produced to show that the ;amyloid-like' material is not degenerative but probably dentine being actively produced by the tumour cells themselves.

The pathology of head and neck tumors: cysts of the jaws, part 12.

The jaws are unique bones of the skeleton because of their intimate involvement with tooth and facial development. Abnormal sequelae of these developmental processes may give rise to cystic lesions later in life. This paper reviews the pathogenesis, clinical features, and behavior of these odontogenic and nonodontogenic cysts. Justification is found for the exclusion of the globulomaxillary, midmandibular, and midpalatine cysts from a current classification. Emphasis is placed on the importance and controversy surrounding the odontogenic keratocyst.

A destructive maxillary cemento-ossifying fibroma following maxillofacial trauma.

The cemento-ossifying fibroma, a mesodermal type of non-odontogenic tumor, is rarely discussed in the otolaryngologic literature. It is a tumor that is seen more in blacks than in whites, appears largely in the elderly, is chiefly located in the mandibular molar or premolar area and is generally neither aggressive nor excessively destructive. The triggering mechanism for its derivation from aberrant periodontal membrane growth or development from endosteal fibrous tissue remains controversial. We report a case of cemento-ossifying fibroma in a 26-year-old Hispanic male which was located in the posterior portion of the maxilla which destroyed the maxillary bone, orbital floor, and the lateral wall of the nose. One year prior to discovery of the lesion the patient sustained severe facial trauma resulting in facial bone fractures. It may be speculated that the trauma sustained was the critical triggering factor allowing for unchecked growth and destruction associated with an otherwise non-aggressive tumor, which may have been present prior to the traumatic incident.

Primary intraosseous squamous cell carcinoma arising in a mandibular keratocyst.

Primary intraosseous carcinoma (P1OC) of the jaws is rare. They either arise de novo or as a consequence of malignant transformation of a benign cyst or tumor. A 56-year-old patient with a P1OC of the mandible arising from an odontogenic keratocyst is described.

Impaired oral health in patients with aspartylglucosaminuria.

OBJECTIVE: The aim of this study was to assess the oral health of patients with aspartylglucosaminuria, a heritable lysosomal storage disorder, and to recommend guidelines for treatment. STUDY DESIGN: Eighty-two patients with aspartylglucosaminuria and 122 control subjects were examined clinically; in addition, panoramic radiographs were evaluated in 61 patients with aspartylglucosaminuria and 61 control subjects. RESULTS: High prevalences of caries, gingivitis, and oral Candida (P < .001), extensive gingival overgrowths (18%; P < .001), benign odontogenic tumors or tumorlike lesions (8%; P = .057), reduced maxillary sinuses (P < .001), limited mouth opening (P < .001), and food retention in the mouth (45%) were the major oral findings that distinguished the patients with aspartylglucosaminuria from the control subjects. Adults with aspartylglucosaminuria had diverse oral health problems, early loss of several permanent teeth being the most disabling feature. CONCLUSIONS: Patients with aspartylglucosaminuria appear to be at a higher risk for a number of oral disorders; however, poor oral hygiene and failure to cooperate increase these patients' risk of dental and periodontal diseases, making successful prevention crucial.

The epidemiology of oral tumours. A report prepared by a Working Group of the Commission on Classification and Statistics for Oral Conditions.

The vital statistics collected by the national and international registries and organizations include information on oral cancer. As their work proceeds and the accumulated information increases and probably also becomes progressively more reliable because of increasing accuracy in clinical diagnosis and death certification, the purpose of epidemiological research, that is, the identification of etiological factors, will come nearer to fulfilment. On the other hand, very little is known about the epidemiology and demography odontogenic tumours. Although these tumours are relatively uncommon they are of considerable practical and theoretical importance to dentists, oral surgeons and pathologists. Since workers in the oral field are especially concerned with these lesions they are in a particularly favourable situation to collate data. Although a lengthy period would be required to amass significant numbers of cases, the effect would be well worth while.

Primary intraosseous carcinoma of the jaws originating in odontogenic cysts.

Primary intraosseous carcinoma (PIOC) of the jaws is a rare lesion and majority of them arise from the epithelial lining of pre-existing odontogenic cysts (OCS). In a case of 20 year old male, PIOC presented a painless swelling extending from left posterior side of the mandible to across the midline with a duration of three months. X-rays revealed a cystic Unilocular radiolucency with well demarcated margin. Aspiration revealed the characteristics of cystic fluid. Histological examination of the biopsy specimen following marsupialisation showed SCA arising in cystic lining. In another case of 24 year old female, PIOC presented a painless swelling on the right side of the mandible with a hollow cavity seen intraorally in the region of the first molar, exfoliated itself in one month. X-rays revealed a cystic radiolucency but with irregular margin centrally. Histologic examination of a biopsy specimen from the lining of the cavity showed SCA originating in cystic lining. In both cases habit of tobacco was absent.

Adenomatoid odontogenic tumor arising in a dental cyst: report of unusual case.

The case of an adenomatoid odontogenic tumor developing over a dentigerous cyst is reported. A 12-year-old boy was referred by his pediatric dentist to the service of Oral and Maxillofacial Surgery of the Asturias Central Hospital (Spain) for evaluation of a radiolucent image compatible with a dentigerous cyst. Microscopic examination revealed the presence of an adenomatoid odontogenic tumor located over the linear epithelium of a dentigerous cyst. Based on the literature, the clinico-pathological, diagnostic, radiological and therapeutic characteristics of the case are commented in detail.

[Dissertation 25 years later, part 2. Development of teeth and odontogenic tumors, now and then]. / Proefschriften 25 jaar na dato 2. Tandkiemen en tumorvorming, toen en nu.

Processes playing a role in normal odontogenesis may also occur in development of odontogenic tumours. Studying odontogenesis may shed new light on the pathogenesis of odontogenic tumours and studying odontogenic tumours may do the same for understanding normal odontogenesis. An overview is given on the developments in this field since the last 25 years. Analysis of protein and gene expression have deepened the understanding of mechanisms playing a role in odontogenesis but thus far has not contributed very much to the knowledge on the pathogenesis of odontogenic tumours.