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牙源性囊肿与牙源性肿瘤是口腔颌面部较为常见的疾病。由于临床表现的多样性,易与其他类型的颌面部囊肿或肿瘤相混淆,而且不同类型的牙源性囊肿和肿瘤其治疗方案也有所区别,所以牙源性囊肿及肿瘤的术前诊断对于其治疗方案的选择起着关键的作用,而在其诊治的过程中,影像学检查起到了非常重要的作用;不同类型的牙源性囊肿及肿瘤的影像学表现也各具特征。本文对常见的牙源性囊肿(牙源性角化囊肿等)及肿瘤(成釉细胞瘤、恶性成釉细胞瘤等)的影像学表现结合实际的影像学图片作简单的介绍,比较各种影像学检查在上述疾病诊断中所具有的优点,以期望能将CT、MRI及全景片等影像学检查手段更好的运用于上述疾病的诊治中。     

Immunohistochemical demonstration of enamel proteins in odontogenic tumors

Immunohistochemical localization of two enamel proteins, amelogenin and enamelin, in comparison with that of keratin, was determined in odontogenic tumors and the allied lesions in order to verify functional differentiation of the tumor cells as ameloblasts. Amelogenin and enamelin were demonstrated in small mineralized foci and in the tumor cells surrounding them in adenomatoid odontogenic tumor (AOT), calcifying epithelial odontogenic tumor (CEOT), and calcifying odontogenic cyst (COC). Hyaline droplets in AOT showed positive staining for both enamel proteins. These mineralized and hyaline materials were not positive for keratin, although tumor cells were positive. On the other hand, no immunoreaction for enamel proteins was obtained in ameloblastoima and odontogenic epithelial cell nests within myxoma and epulis. The results suggest that tumor cells of AOT and CEOT and lining epithelial cells of COC show ameloblastic differentiation in part, but that ameloblastoma cells do not attain functional matauration as secretory phase ameloblasts.     

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由于颌骨内的成牙组织常可作为囊肿和肿瘤的组织来源,因此颌骨是人类骨骼中最好发上皮性囊肿和肿瘤的部位。这类牙源性病损好发于年轻人,可造成颌骨及邻近组织的破坏,导致口腔颌面部外形改变,某些侵袭性病损具有较高的复发倾向,可对患者的生存质量及心理健康造成严重影响。本文着重讨论几种常见的牙源性囊肿与牙源性肿瘤的病理学诊断。     

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牙源性肿瘤是颌骨最常见病损之一,临床上绝大多数牙源性肿瘤均发生在颌骨内。良性肿瘤多无自觉症状,直至肿瘤生长到一定程度出现颌面部组织膨隆方被发现,早期患者多是在做牙髓治疗或体检照片时无意中发现的,除非继发感染,患者一般没有疼痛等不适感觉。牙源性肿瘤的病理学分类很多,基于局部生物学行为的特点,WHO在2005年将原来的牙源性角化囊肿和牙源性钙化囊肿归列入牙源性肿瘤。牙源性肿瘤的临床表现多样,一般需要结合病理学检查确诊。手术处理是治疗牙源性肿瘤惟一有效的方法,但如何选择有效术式是临床医师需要慎重考虑的问题。本文就几种常见牙源性肿瘤的外科治疗作了简要概述。     

Evaluation of mast cells in periapical cysts, dentigerous cysts, and keratocystic odontogenic tumors

J Oral Pathol Med (2012) 41 : 630–636 Background: Several cell types are associated with the development of cystic and tumoral odontogenic lesions. Among inflammatory cells, mast cells can be associated with their pathogenesis. The aim of this study was to analyze mast cells in periapical cysts, dentigerous cysts, and keratocystic odontogenic tumors. Methods: Tissue sections were submitted to toluidine blue staining and immunohistochemistry with antibody anti‐tryptase (clone G3). Mast cells were quantitated using Image‐Pro Plus software to obtain the mean number of mast cells in three regions: epithelial, superficial portion of the fibrous wall and deep portion of the fibrous wall from 20 periapical cysts, 20 dentigerous cysts (six non‐inflamed and 14 inflamed) and 20 keratocystic odontogenic tumors (four non‐inflamed and 16 inflamed). Results: The mean number of mast cells detected per lesion by immunohistochemistry (4.1) was higher than by histochemistry (1.5) (P < 0.0001). Inflamed dentigerous cysts and keratocystic odontogenic tumors showed a higher mean number of mast cells than non‐inflamed lesions in all regions. The deep region from all cysts showed the highest mean number of degranulated mast cells, except for non‐inflamed keratocystic odontogenic tumors analyzed by immunohistochemistry. Conclusions: Immunohistochemical staining detected higher number of mast cells than histochemistry. The higher number of mast cells observed in inflamed lesions could indicate the participation of these cells in the inflammatory response in odontogenic lesions. The prevalence of degranulated mast cells in the deep region suggests intense activity of these cells, possibly related to growth of cystic lesions.     

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.     

Radiographic analysis of a calcifying odontogenic cyst

The Radiographic appearance of 33 cases of calcifying odontogenic cyst (COC) from 1971 to 1998 were analyzed. COC has a variety of radiographic appearances. According to the WHO classification¹⁾, such cysts can be divided into five subtypes in order to be considered as central COC and one peripheral type. The subtypes are as follows: I: Unilocular, II: COC associated with odontoma, III: alveolar bone type, IV: compound type, V: recurrences that have become malignant. Ghost cells are an important feature in the diagnosis of COC. However, ghost cells may occur in other tumors as well. Differentiation of the types of COC according to radiographic appearance will aid the clinical diagnosis and treatment of odontogenic cysts.     

Epidermal growth factor receptor in odontogenic cysts and tumors

The expression of epidermal growth factor receptor (EGFR) was investigated in 67 cases of odontogenic cysts and 35 cases of odontogenic tumors using monoclonal antibody to EGFR (Biomarker, Israel) to determine the presence and significance of this transmembrane growth factor receptor. The cystic epithelial cells of odontogenic cystic lesions (keratocyst 60%; primordial cyst 75%; radicular cyst 35%; and follicular cyst 47.4%) were positive to EGFR staining. Cytochemical characterization of EGFR in those cystic epithelium was cell membrane positive type as in the normal epithelium. No expression of EGFR was found in the odontogenic tumors. This diversity of EGFR represents no binding activity of EGF, or loss of EGFR in the tumor cell upon EGFR mediated growth in odontogenic tumors was suggested a different tumor cell growth factor status or microenvironment in cell proliferation mechanism at the cellular level in cysts and tumors of odontogenic origin.     

Ameloblastoma, calcifying epithelial odontogenic tumor, and glandular odontogenic cyst show a distinctive immunophenotype with some myoepithelial antigen expression

Background:  Odontogenic neoplasms have some morphologic overlap with salivary gland neoplasms, many of which show myoepithelial differentiation. In the 1980s, an ultrastructural study identified a population of myoepithelial-like cells in calcifying epithelial odontogenic tumor. Myoepithelial derived tumors have since been shown to have distinct immunohistochemical profiles.
Methods:  We examined a series of odontogenic neoplasms, including 11 ameloblastomas, four calcifying epithelial odontogenic tumors, five glandular odontogenic cysts (GOCs), and five keratocystic odontogenic tumors with a panel of myoepithelial-associated immunohistochemical stains. We also assessed representative control examples of oral mucosa, odontogenic rests, and dentigerous cysts.
Results:  All of the neoplastic and non-neoplastic oral epithelium-derived entities share a p63-positive, high molecular weight cytokeratin (CK5/6)-positive immunophenotype. Calponin reactivity was at least focally present in two of four calcifying epithelial odontogenic tumors, three of five GOCs, and 10 of 11 ameloblastomas; the sole completely non-reactive ameloblastoma represents a lung metastasis. One case of calcifying epithelial odontogenic tumor was focally positive for glial fibrillary acidic protein. However, other more definitive markers of myoepithelial differentiation, including S-100 and smooth muscle actin, were negative. Two of three calcifying epithelial odontogenic tumors and five of five GOCs were also positive for a low molecular weight cytokeratin (CK7).
Conclusions:  Ameloblastomas, GOCs, and calcifying epithelial odontogenic tumors show a distinctive immunophenotype which overlaps with that of myoepithelial-derived salivary gland neoplasms but does not provide definitive support for myoepithelial differentiation.     

Human cytomegalovirus is present in odontogenic cysts

INTRODUCTION: Recent studies suggest that some viruses, including human cytomegalovirus (CMV), may be involved in the pathogenesis of periapical lesions. Since periapical cysts (PCs) represent the next stage in the evolution of periapical granuloma, it seemed reasonable to investigate the presence of CMV in PCs and any possible relationship between its presence and the clinical features of those cysts, as well as to compare the results obtained with corresponding findings in non-inflammatory lesions, like odontogenic keratocysts (OKCs). METHODS: Samples of 33 PCs and 10 OKCs, obtained at the time of surgery, were used for the detection of CMV DNA by polymerase chain reaction. Presence of the virus was correlated with clinical and radiographic features of the cysts. RESULTS: CMV was detected in 18 PCs (54.5%) and six OKCs (60%). The presence of CMV was more frequent in cyst samples collected from patients who reported previous episodes of acute infection. The presence of sinus tract was more frequent in CMV-positive cysts and CMV presence was less frequent in a group of cysts showing signs of acute inflammation at the time of sample collection. The mean sizes of CMV-positive and CMV-negative PCs were almost the same; CMV-positive OKCs were slightly larger than CMV-negative OKCs. None of these results proved to be statistically significant. CONCLUSION: The presence of CMV in the cystic wall is a common feature of both inflammatory and non-inflammatory odontogenic cysts. Although this study has not proved that CMV affects pathogenesis of odontogenic cysts, such a possibility could not be ruled out.     

Cystic variant of calcifying epithelial odontogenic tumor

The calcifying epithelial odontogenic tumor is a rare benign odontogenic neoplasm of the jaw. Clinically, calcifying epithelial odontogenic tumor manifests as an intraosseous lesion (central type) in the majority of cases (95%). Extraosseous or peripheral lesions account for less than 5% of cases. Calcifying epithelial odontogenic tumor can be associated with an impacted tooth and give a radiographic simulation of dentigerous cyst. Most calcifying epithelial odontogenic tumors are solid in nature, histopathologically, and might have few cyst-like spaces within them. However, a true cystic calcifying epithelial odontogenic tumor is a rare possibility. We describe a case of a true cystic variant of calcifying epithelial odontogenic tumor in a 30-year-old male, which to our knowledge, is only the second reported case.     

Pigmented lateral periodontal cyst and other pigmented odontogenic lesions

OBJECTIVE: To report a case of lateral periodontal cyst (LPC) with marked melanin pigmentation in a 38-year-old Black male and to discuss the phenomenon of melanin pigmentation in odontogenic cysts and tumors.
RESULTS: Histologically, the epithelial lining of the LPC contained an abundant amount of melanin granules throughout the entire epithelium. Ultrastructurally, epithelial cells contained mature melanosomes (stage IV melanosomes). Melanophages containing aggregates of melanosomes were identified in the connective tissue cyst wall. Perusal of the literature revealed that melanin pigmentation in odontogenic lesions is uncommon. Melanin has been reported in calcifying odontogenic cyst (18 cases), odontogenic keratocyst (8 cases), adenomatoid odontogenic tumor (3 cases), ameloblastic fibroma (3 cases), odontoma (2 cases), and amelobastic fibro-odon-toma, odonto-ameloblastoma, and odontogenic fibroma (I case each).
CONCLUSIONS: Almost all pigmented odontogenic lesions occurred in Blacks and Asians; they are almost non-existent in Whites. Thus, racial pigmentation probably plays an important role in such lesions.     

Squamous odontogenic tumor and squamous odontogenic tumor-like proliferations in odontogenic cysts: An updated analysis of 170 cases reported in the literature

Purpose

To integrate the available data published on squamous odontogenic tumors (SOT) and squamous odontogenic tumor-like proliferations in odontogenic cysts (SOT-LPOC) into a comprehensive analysis of their clinical/radiologic features.

Analysis of the neoplastic nature and biological potential of sporadic and nevoid basal cell carcinoma syndrome-associated keratocystic odontogenic tumor

BACKGROUND: Keratocystic odontogenic tumor (KCOT), also known as odontogenic keratocyst, is a benign cystic neoplasm, which may be associated with nevoid basal cell carcinoma syndrome (NBCCS) and if it does, will occur as multiple cystic lesions. KCOT is locally destructive despite its bland histological features. However, the neoplastic nature of KCOT is not well established. Heparanase is an endo-d-glucuronidase enzyme that specifically cleaves heparan sulfate (HS) and the increase of its level in tumors promotes invasion, angiogenesis, and metastasis. METHODS: To investigate the neoplastic character of KCOT, we studied the localization patterns of heparanase in KCOT, focusing on the differences between sporadic and NBCCS-associated KCOTs, by immunohistochemistry and in situ hybridization. To compare the expression pattern of these cysts with non-tumorous odontogenic developmental cyst, dentigerous cyst was included. RESULTS: All the odontogenic cysts showed positive immunoreaction for heparanase protein in various intensities. The expression pattern of heparanase gene corresponded to that of protein expression. Interestingly, intense gene and protein expressions were observed in KCOT associated with NBCCS compared with sporadic ones and dentigerous cyst. CONCLUSIONS: The results implied that heparanase expression may be correlated with the neoplastic properties of KCOT, particularly in NBCCS-associated cases.     

44例牙源性纤维瘤临床病理分析

目的 研究牙源性纤维瘤的临床病理特点。方法 按世界卫生组织（WHO）1992年牙源性肿瘤分类标准对44例牙源性纤维瘤的临床病理特点及生物学行为进行回顾性研究。结果 本组44例中，女31例，男13例。发病年龄2－70岁，平均29岁。中心型5例，周边型39例。上颌19例，下颌25例。X线及手术中见4例牙槽骨明显破坏。术后有4例复发。组织学上表现为WHO型39例、单纯型4例和牙源性颗粒细胞瘤1例。肿瘤无明显包膜，边界尚清。结论 牙源性纤维瘤不是单一性肿瘤，组织学上表现为WHO型、单纯型和牙源性颗粒细胞瘤。诊断时应与增殖性牙滤泡、粘液瘤等相鉴别。     

Asymptomatic expansion of the mandible

Frequently, the first noticeable sign of an odontogenic myxoma is a slowly enlarging, painless expansion of the jaw. Spreading, loosening, and migration of teeth in the area commonly occur. In the early stages, the tumor is asymptomatic, and detection is made only by routine radiographs. Clinicians should be aware of the radiographic changes caused by this benign odontogenic tumor, and include it in their differential consideration of lesions presenting such changes in the jaws. A typical case of a fairly large odontogenic myxoma has been presented. The clinical, radiographic, and histological presentations have been discussed. The tumor was treated by en bloc resection with immediate bone and nerve reconstruction. The patient responded well to therapy and no tumors were found at the 1 year follow-up examination.     

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牙源性囊肿是一组常见于颌骨内的良性病变,一般可根据临床体征和影像学发现作出初步诊断。颌骨牙源性囊肿的手术治疗方法应根据囊肿类型、患者年龄、病变大小及罹患部位等决定。青少年含牙囊肿,预期囊内含牙可自行萌出者,可采用袋形术。病变范围较小的颌骨牙源性囊肿,刮除术为最好的治疗方法。若根尖周囊肿的病源牙可保留,术前应完成根管治疗。术中辅以Carnoy液处理囊壁可减少角化囊肿术后复发。破坏范围大的颌骨牙源性囊肿可选择第一期袋形术,第二期刮除术,有利于减少邻近结构的损伤。颌骨切除术较少应用于治疗颌骨囊肿,主要适应证是病变破坏范围大,多次复发的牙源性角化囊肿。     

牙源性囊肿上皮增殖活性的研究

目的：研究牙源性角化囊肿,含牙囊肿,根尖囊肿3种主要的牙源性囊肿衬里上皮的细胞增殖活性,方法：应用Ki-67单克隆抗体免疫组化LSAB法对30例牙源性囊肿进行免疫组化染色,结果通过计算机图像分析,计算单位面积衬里上皮内（mm2)阳性细胞数,进行统计学分析,结果：牙源性角化囊肿衬里上皮有较多的Ki-67阳性细胞,明显高于含牙囊肿和根尖囊肿;正常口腔粘膜未见Ki-67阳性表达,结论：Ki-67在不同的牙源性囊肿中表达的差异显示了它们具有不同的增殖和分化过程。     

Histopathologic study of epithelial components in the connective tissue wall of unilocular type of calcifying odontogenic cyst

Histopathologic study of satellite cysts and odontogenic epithelial islands in connective tissue wall of unilocular type of calcifying odontogenic cyst (COC) was made. The material was 13 cases consisting of 3 simple unicystic COCs, 9 odontome producing COCs and 1 ameloblastomatous proliferating COC. Satellite cysts were found in 6 cases, and were histologically classified into following types: simple cystic, odontome producing and ameloblastomatous. Histologic types of satellite cysts did not coincide with those of main cystic lesions in some cases. Odontogenic epithelial islands with or without proliferating feature were found in 9 cases, and were found in all cases with satellite cysts. Melanin and melanocytes were seen in an ameloblastomatous satellite cysts of 1 of 3 pigmented COCs.     

Odontogenic myxoma: histochemical and ultrastructural study

Three cases of odontogenic myxoma are presented, two of which were located in the mandible and one in the maxilla. All cases demonstrated similar morphology by light microscopy. Immunohistochemical studies demonstrated positive reaction with antibodies to vimentin and actin, and negative reaction to antibody to S-100 protein. A 127-day-old human tooth bud was used as a control. The ultrastructural features performed on Case 3, when combined with the immunohistochemical findings suggest that the cells comprising odontogenic myxoma are of myofibroblastic origin.