单囊型成釉细胞瘤临床病理及凝集素免疫组织化学研究

目的 研究单囊型成釉细胞瘤的临床病理及凝集素免疫组织化学特点，探索有助于诊断和临别诊断的组织学标记物。方法 对４０例单囊型成釉细胞瘤行ＨＥ染色及组织学观察；并对其中的２５例行荆豆凝集素（ＵＥＡ－１）、兀鹰血凝集素（ＢＳＡ－１）免疫组织化学染色。结果 ４０例 单囊型成釉细胞瘤，组织学上可分为３个亚型：第一型５例（１２．５％），第二型２０例（５０．０％），第三型１５例（３７．５％）；ＵＥＡ－１、ＢＳＡ     

Small Central Odontogenic Fibroma Mimicking Hyperplastic Dental Follicle and Dentigerous Cyst

Central odontogenic fibroma has been defined as a benign odontogenic tumor, representing the intraosseous counterpart of a peripheral odontogenic fibroma. The odontogenic fibroma is a rare tumor. Differential diagnosis of radiolucent lesions in the molar-premolar region of mandible which involve impacted tooth may include central odontogenic fibroma, hyperplastic dental follicle, dentigerous cyst, unicystic ameloblastoma, and keratocystic odontogenic tumor. We describe an example of a small central odontogenic fibroma mimicking hyperplastic dental follicle and dentigerous cyst, resulting in uneruption of a primary tooth.     

Comparison of angiogenesis in keratocystic odontogenic tumours, dentigerous cysts and ameloblastomas

Objective:  The aim of the present study was to evaluate and compare angiogenesis in keratocystic odontogenic tumours, dentigerous cysts (DCs) and ameloblasomas using monoclonal antibody against CD34.
Materials and methods:  Microvessel density was assessed in a total of 53 cases including 20 keratocystic odontogenic tumours, 13 DCs and 20 ameloblastomas (14 solid and six unicystic variants). Microvessel density was expressed as the mean number of microvessels per high-power-field.
Results:  Statistically significant differences in mean microvessel density were observed between keratocystic odontogenic tumours, DCs and solid ameloblastomas ( P  < 0.001). Mean microvessel density was significantly higher in solid ameloblastomas compared with both keratocystic odontogenic tumours and DCs; and was also significantly higher in keratocystic odontogenic tumours than in DCs.
Conclusion:  Within the limitations of the present study, it can be suggested that angiogenesis may be one of the mechanisms possibly contributing to the different biological behaviours of keratocystic odontogenic tumours, DCs and solid ameloblastomas.     

Inability to distinguish ameloblastomas from odontogenic cysts based on expression of blood cell carbohydrates

This study was designed to confirm the report by Vedtofte and coworkers that the epithelium of ameloblastomas can be distinguished from that of nonneoplastic odontogenic cysts by differences in expressivity of cell surface carbohydrates with blood group specificity. Immunoperoxidase techniques were used to study four radicular cysts, seven dentigerous cysts, six ameloblastomas, and six examples of plexiform unicystic ameloblastoma. No consistent differences were found in the expressivity of the blood group carbohydrates A, B, and H type 2 in the nonneoplastic odontogenic cysts as compared to the ameloblastomas. Consequently, the demonstration of these blood group carbohydrates is of no value in the differential diagnosis of nonneoplastic odontogenic epithelium from ameloblastomas, including especially the plexiform unicystic ameloblastoma, the pattern that so closely resembles hyperplastic odontogenic epithelium.     

Unicystic ameloblastoma of the maxilla: a case report

Unicystic ameloblastoma is believed to be less aggressive and responds more favorably to conservative surgery than the solid or multicystic ameloblastomas. This report is a rare case of unicystic ameloblastoma of the maxilla that was treated by enucleation under suspicion of a radicular cyst related to a dens in dente. The neoplastic nature of the lesion became evident only when the enucleated material was available for histologic examination. With this report, the authors illustrate the importance and complexity of a differential diagnosis of lesions with a cystic aspect in the anterior region of the maxilla, among them - inflammatory radicular cysts, odontogenic keratocysts, adenomatoid odontogenic and unicystic ameloblastoma. Relevant diagnostic problems and choice of treatment of unicystic ameloblastoma are presented along with a review of the literature.     

Significance of podoplanin expression in keratocystic odontogenic tumor

J Oral Pathol Med (2010) 39 : 110–114
Background:  The most important clinical features of the keratocystic odontogenic tumor (KCOT) are its potential for locally destructive behavior, a tendency to recur, and its origin in the odontogenic epithelium. The clinical features of KCOT are similar to those of ameloblastoma (AM). Histologically, KCOT is distinguished from jaw cyst with keratinization (orthokeratinized odontogenic cyst; OOC). However, current scientifically based clinical parameters cannot predict any potential for neoplastic behavior, or aggressive and localized invasiveness, in patients with KCOT. We have shown that podoplanin, a lymphatic endothelial marker, is highly expressed in AM. The purpose of this study was to determine the usefulness of podoplanin for reclassification of the odontogenic keratocyst (OKC) from cyst to tumor status.
Methods:  Paraffin-embedded tissue specimens of 57 OKCs (46 KCOTs and 11 OOCs) and 15 dentigerous cysts (DCs) were immunohistochemically examined using antibody against podoplanin.
Results:  Immunohistochemical reactivity for podoplanin was detected in the cell membrane and cytoplasm of most of the basal and suprabasal layer, areas of budding basal cell proliferation, epithelial nests and peripheral cells of daughter cysts in the stromal connective tissue in KCOTs. In the case of OOC and DC, only cases associated with inflammation were positive for podoplanin.
Conclusion:  Podoplanin is strongly expressed in KCOTs in comparison with OOCs. The pattern of staining for podoplanin in KCOT could be related to its neoplastic nature, and suggests a role of the protein in tumor invasiveness.     

Parathyroid hormone-related protein (PTHrP) expression in ameloblastoma

OBJECTIVE: Parathyroid hormone-related protein (PTHrP) production has been demonstrated in a variety of tumor subtypes. Local production of PTHrP by metastatic tumor cells in bone has been linked to bone destruction and tumor growth. Ameloblastoma (AB) is a relatively common odontogenic epithelial neoplasm that manifests local infiltrative intraosseous growth. AB recapitulates the developing enamel epithelium, in which PTHrP recently has been demonstrated. Yet PTHrP expression in a series of ABs has not been studied to date. The purpose of this investigation is to assess the expression of PTHrP in ameloblastoma. STUDY DESIGN: Formalin-fixed, paraffin-embedded tissue sections of ameloblastoma (n = 30; 24 conventional, 4 unicystic, and 2 arising in dentigerous cyst) were immunostained with anti-PTHrP antibody using a multistep streptavidin-peroxidase technique. Semiquantitative scoring of immunoreactivity was assessed as mild, moderate, and intense. RESULTS: All cases (100%) demonstrated positive immunoreactivity, with mild reaction in 3 conventional ABs, 1 unicystic and 1 AB arising in dentigerous cyst, and with moderate reaction in 12 conventional ABs, 3 unicystic and 1 AB arising in dentigerous cyst. Intense immunoreactivity was seen in 9 cases of conventional AB. This difference in immunostaining was not statistically significant (Sigma2 = 4.41, df = 4, P = .358). CONCLUSION: The results of this investigation suggest that PTHrP may play a significant role in local bone resorption, offering at least partial explanation for the tumor's infiltrative growth and destructive behavior. The uniformity of PTHrP expression by AB, as detailed in this study, may harbor significant therapeutic implications, particularly through PTHrP-blocking treatment modalities.     

Surgical management of dentigerous cyst and keratocystic odontogenic tumor in children: a conservative approach and 7-year follow-up

Dentigerous cyst (DC) is one of the most common odontogenic cysts of the jaws and rarely recurs. On the other hand, keratocystic odontogenic tumor (KCOT), formerly known as odontogenic keratocyst (OKC), is considered a benign unicystic or multicystic intraosseous neoplasm and one of the most aggressive odontogenic lesions presenting relatively high recurrence rate and a tendency to invade adjacent tissue. Two cases of these odontogenic lesions occurring in children are presented. They were very similar in clinical and radiographic characteristics, and both were treated by marsupialization. The treatment was chosen in order to preserve the associated permanent teeth with complementary orthodontic treatment to direct eruption of the associated permanent teeth. At 7-years of follow-up, none of the cases showed recurrence.     

Clinicopathological evaluation of 164 dental follicles and dentigerous cysts with emphasis on the presence of odontogenic epithelium in the connective tissue. The hypothesis of “focal ameloblastoma”

Objectives: Some ameloblastomas presumably originate from odontogenic epithelium within the connective tissue of dental follicles and dentigerous cysts. Therefore, it would seem reasonable to discuss as whether odontogenic epithelium proliferations, frankly displaying ameloblastomatous features (“focal ameloblastoma”), should be considered as an “early” ameloblastoma. Study Design: Histopathological reports from 164 dental follicles and dentigerous cysts from the Department of Oral and Maxillofacial Surgery/Oral Pathology of the VU Free University medical center in Amsterdam, The Ne-therlands, were reviewed. Histopathological slides from 39 cases reporting the presence of odontogenic epithelium within the connective tissue were re-evaluated in order to assess the possible presence of focal ameloblastomas. Results: Focal ameloblastomas were detected in one dental follicle and in two dentigerous cysts. During a follow-up period of 6, 8 and 22 years, respectively, no clinical signs of (recurrent) ameloblastoma have occurred in these patients. Conclusions: Focal ameloblastoma possibly represents the early stage of ameloblastoma development. Key words:Ameloblastoma, odontogenic epithelium, dentigerous cyst, dental follicle.     

Frequency of odontogenic cysts and tumors: a systematic review

A systematic review of the literature from 1993 to 2011 was undertaken examining frequency data of the most common odontogenic cysts and tumors. Seven inclusion criteria were met for the paper to be incorporated. In the preliminary search 5231 papers were identified, of these 26 papers met the inclusion criteria. There were 18 297 odontogenic cysts reported. Of these there were 9982 (54.6%) radicular cysts, 3772 (20.6%) dentigerous cysts and 2145 (11.7%) keratocystic odontogenic tumors. With the reclassification of keratocystic odontogenic tumor in 2005 as an odontogenic tumor, there were 8129 odontogenic tumors reported with 3001 (36.9%) ameloblastomas, 1163 (14.3%) keratocystic odontogenic tumors, 533 (6.5%) odontogenic myxomas, 337 (4.1%) adenomatoid odontogenic tumors and 127 (1.6%) ameloblastic fibromas. This systematic review found that odontogenic cysts are 2.25 times more frequent than odontogenic tumors. The most frequent odontogenic cyst and tumor were the radicular cyst and ameloblastoma respectively.     

牙源性角化囊肿上皮细胞增殖动力学初步研究

目的探讨角化囊肿上皮细胞增殖特性,进一步了解角化囊肿的生物学行为,为临床治疗和预防复发提供一定的依据。方法采用增殖细胞核抗原（ｐｒｏｌｉｆｅｒａｔｉｎｇｃｅｌｎｕｃｌｅａｒａｎｔｉｇｅｎ,ＰＣＮＡ）免疫组化法和细胞核ＤＮＡ含量分析,对牙源性角化囊肿、根尖囊肿、含牙囊肿和造釉细胞瘤上皮细胞进行对比研究。结果角化囊肿上皮细胞增殖活跃,与造釉细胞瘤相似。提示角化囊肿生物学特性为上皮细胞主动生长,而非被动性膨胀生长。结论角化囊肿可视为具有侵袭性生长的良性肿瘤,提出命名为“牙源性角化囊性瘤”更能反应其生物学特性     

Ki-67 expression in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising from dental cysts

This study investigated whether or not an ameloblastoma developing in the wall of a dentigerous cyst is a distinct lesion from the unicystic ameloblastoma. An immunohistochemical evaluation of Ki-67 in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising in dentigerous cysts was done. The values of Ki-67 positivity were 3.14 for the dentigerous cyst, between 5.32 and 16.56 for unicystic ameloblastoma, and 11.77 for ameloblastoma arising in a dentigerous cyst. Statistically significant differences were found between the dentigerous cyst and the unicystic ameloblastoma and between the dentigerous cyst and the ameloblastoma arising from a dentigerous cyst. No statistically significant difference was present between unicystic ameloblastoma and ameloblastoma arising from dentigerous cyst. These immunohistochemical data confirm the hypothesis that an ameloblastoma arising from a dentigerous cyst has a similar biological behavior to the unicystic ameloblastoma and should be considered as merely a histologic variant.     

Calretinin expression in odontogenic cysts

Calretinin is a calcium-binding protein with a possible role as a calcium buffer, calcium-sensor, or regulator of apoptosis. Calretinin is expressed in neural tissue, is a specific marker of mesothelial cells, and has been demonstrated in the odontogenic epithelium during odontogenesis in rat molar tooth germs. Moreover, it has been found to be expressed in a high proportion of solid, unicystic, and multicystic ameloblastomas, whereas, on the contrary, no positive staining has been found in odontogenic keratocysts, residual cysts, and dentigerous cysts. The purpose of this study was to evaluate calretinin expression in radicular cysts, follicular cysts, orthokeratinized keratocysts, and parakeratinized keratocysts. A total of 70 odontogenic cysts, 24 radicular cysts, 24 follicular cysts, and 22 odontogenic keratocysts (10 orthokeratinized keratocysts, 12 parakeratinized keratocysts) were evaluated. All the radicular cysts, follicular cysts, and orthokeratinized keratocysts were negative. However in 8 of 12 parakeratinized keratocysts, there was a positivity to calretinin in the parabasal-intermediate layers of the cyst epithelium. This positivity to calretinin in the parabasal layers in parakeratinized keratocysts, similar to that found for other markers like PCNA and p53, could point to an abnormal control of the cell cycle and could help to explain the differences in the clinical and pathologic behavior of odontogenic keratocysts, in particular the differences found between orthokeratinized keratocysts and parakeratinized keratocysts.     

Mandibular ameloblastoma. A review of the literature and presentation of six cases

Ameloblastoma is a benign odontogenic tumour of epithelial origin without induction in the connective tissue. In treating this type of tumour, it is important to assess the clinical type (solid, multicystic, unicystic, peripheral), localisation, and size of the tumour as well as age of the patient. Articles have recently been published with the purpose of providing updated knowledge and therapeutic approaches to ameloblastoma. We present six cases of patients with localised mandibular ameloblastoma who were treated during the last seven years. We present data on clinical appearance, histological characteristics, and therapeutic approach that was used, which included excision of the lesion, perilesional drilling of the bone, or block resection, according to the type of ameloblastoma. Lastly, we analysed follow-up measures and the rate of recurrence in these patients. The aim of this paper is to review the concepts relating to ameloblastoma that have been published recently and to assess their influence on the clinical attitude taken when facing this pathology, using our experience with ameloblastoma as a starting point to illustrate this discussion.     

Bcl—xL、Livin在牙源性角化囊性瘤组织中的表达及意义

目的：检测Bcl-xL、Livin在牙源性角化囊性瘤囊壁上皮细胞中的表达,初步探讨凋亡抑制蛋白在牙源性角化囊性瘤发生发展中的意义。方法：免疫组化法检测32例牙源性角化囊性瘤,30例单囊型成釉细胞瘤及30例含牙囊肿手术切除标本中Bcl-xL、Livin蛋白的表达。结果：Bcl-xL在牙源性角化囊性瘤、单囊型成釉细胞瘤及含牙囊肿中的阳性表达率分别为84．38％、90．00％、36．67％,Bcl-xL在牙源性角化囊性瘤中的阳性表达率高于含牙囊肿。 Livin在牙源性角化囊性瘤、单囊型成釉细胞瘤及含牙囊肿囊壁中阳性表达率分别为59．38％、66．67％、20．00％,Livin在牙源性角化囊性瘤中的阳性表达率高于含牙囊肿（P＜0．05）,牙源性角化囊性瘤中Bcl-xL与Livin的表达呈正相关（r＝0．483,P＜0．05）。结论：Bcl-xL、Livin在牙源性角化囊性瘤的发生发展中可能起一定作用,并且二者可能具有协同效应。     

The Management of Aggressive Cysts of the Jaws

There are essentially six types of aggressive cysts of the jaws that require special attention, so as to avoid recurrence, or even worse, widespread disease. They include, botryoid cysts, cysts in which carcinoma’s arise, glandular odontogenic cysts, calcifying cystic odontogenic tumour, previously called calcifying odontogenic cyst and unicystic ameloblastoma and keratocystic odontogenic tumor, previously called odontogenic keratocysts. The estimated incidence of these cysts, based on some review studies has been discussed. The main issue, however, when treating a cyst of the jaws is; how sure can one be that the lesion is benign or potentially aggressive? In order to answer this question it is important to know how these cysts commonly present. The clinical presentation, frequency of occurrence and suggested modes of treatment has been addressed.     

Ameloblastoma in young persons: a clinicopathologic analysis and etiologic investigation

Ameloblastoma, an odontogenic tumor of ectodermal origin, has been reported to arise, on rare occasions, in a primordial or dentigerous cyst of a young person. Numerous authors have suggested differing nomenclatures for these ameloblastomas (e.g., mural, unicystic, monocystic, intracystic, cystogenic, cystic, plexiform unicystic) and have sought to describe and classify the clinical and histopathologic features. These tumors have been characterized as a distinct variant exhibiting less aggressive behavior and a lower rate of recurrence than conventional ameloblastoma. Furthermore, various etiologic factors have been proposed for these cystic ameloblastomas, including (1) nonspecific irritational factors such as extraction, caries, trauma, infection, inflammation, or tooth eruption; (2) nutritional deficit disorders, and (3) viral infection. The files of the combined accessioned cases of Emory University's and Temple University's oral pathology laboratories were searched and a review of the literature was performed. Thirty-eight cases of mandibular ameloblastoma (37 intraosseous, 1 peripheral) in persons 19-year-old and younger were found from a combined total of 311 accessioned cases of ameloblastoma (12.2%). The average age at diagnosis was 10.4 years for the 18 males and 20 females. Of the 33 cases in which race was stated, 19 (57.6%) were white and 14 (42.4%) were black. In the 28 cases in which a clinical diagnosis was offered, fifteen (53.6%) were thought to be dentigerous cysts. Ten cases from patients less than 19 years old were investigated by means of an immunohistochemical staining technique for the detection of human papilloma virus (HPV) genus-specific structural antigen in formalin-fixed, paraffin-embedded tissue. Three of the ten cases (cases 31, 37 and 38) were positive for HPV capsid antigen, whereas none of ten randomly selected ameloblastomas in adults was positive. A discussion of the clinical and histopathologic comparative findings, with emphasis on treatment results and possible HPV etiology, is included. The preliminary nature of finding HPV in the tumor cells is stressed, with recommendation for further verification and typing with the more sensitive in situ hybridization technique.     

Adenomatoid Odontogenic Tumor (AOT) Arising from a Dentigerous Cyst: Literature Review and Report of a Case

Adenomatoid odontogenic tumor (AOT) is an uncommon benign tumor of odontogenic origin composed of odontogenic epithelium in a variety of histopathological patterns. These lesions are usually solid but are occasionally cystic. AOT has been reported to occur in association with odontogenic cysts. Very few cases have been described that arise in association with a dentigerous cyst. A systematic search of the English-language medical literature in PubMed and Medline search (keywords adenomatoid odontogenic tumor, dentigerous cyst) data bases revealed only ten such cases.The present case is very unique, exceptional and first of this kind that occurred in the posterior mandible associated with an impacted lower first premolar in a 19-year old female patient. The intraosseous follicular AOT, as this case reported here, frequently resemble dentigerous cysts. There is an uncertainty whether the lining of an associated cyst represents a true dentigerous cyst, cystic change within an AOT or may represent a distinct entity. We believe that this case represents an odontogenic cyst with neoplastic change. Hence, in such cases, the final diagnosis should be made on the basis of histological examination of extensive tissue sampling of entire excised tissue specimen. Further studies to determine whether the AOT derived from an odontogenic cyst could represent a distinct variant are to be done.