Argyrophilic nucleolar organizer regions (AgNORs) in odontogenic myxoma (OM) and ameloblastic fibroma (AF)

Ten cases of odontogenic myxoma (OM) and six cases of ameloblastic fibroma (AF) were subjected to comparative analysis by the AgNOR technique, in order to determine a possible difference in cell proliferation index between these lesions. The mean AgNOR number of the mesenchymal component of AF was compared with its epithelial component and the difference was not found to be statistically significant. The mean AgNOR index of the AF group was significantly higher than that of the OM group. Moreover, the mesenchymal component of AF demonstrated increased AgNOR numbers compared with that of OM (P<0.05). These results suggest that the epithelial and mesenchymal components of AF may have similar cell proliferative activity. However, the cell proliferative index of this lesion seems to be higher than that of OM.     

Ameloblastic fibroma in a young cat

The results of a histological and histochemical study of an ameloblastic fibroma in the maxilla of a young cat are presented. Staining with Picrosirius red revealed the presence of collagen fibers of abnormal packing in the ectomesenchy-mal component of the tumor. A discussion relating to the classification of the tumor with reference to those in humans is presented.     

Ectomesenchyme of ameloblastic fibroma reveals a characteristic distribution of extracellular matrix proteins

The distribution of collagens type I, IV and VI, procollagen type III and of undulin was studied in four cases of ameloblastic fibroma (AF). The ectomesenchyme of AF revealed an as yet unobserved organization of these extracellular matrix proteins with collagen type VI clearly predominating over collagen type I, procollagen type III and undulin, that showed a weak and amorphous distribution throughout the tumor stroma. Undulin, a glycoprotein that is associated with mature collagen fibrils and with differentiated tissues, was not detectable in the tumor stroma of AF except for a slow expression around capillaries and in areas with a high cellularity. We could demonstrate that the characteristics of extracellular matrix composition allowed a clear distinction between the ectomesenchyme of AF and the adjacent normal mesenchymal stroma. Due to the specific staining patterns it was possible to detect epithelial tumor islands outside the typical ectomesenchymal stroma. Our findings furthermore indicate that epithelial cells of AF invade the adjacent normal mesenchyme possibly inducing de novo formation of ectomesenchymal tumor stroma.     

Ameloblastic fibroma and related lesions: a clinicopathologic study with reference to their nature and interrelationship

BACKGROUND: Ameloblastic fibroma (AF) and related lesions constitute a group of lesions, which range in biologic behavior from true neoplasms to hamartomas. The aim of this study was to elucidate the nature and interrelationship of this group of lesions. METHODS: Clinical and pathological studies were undertaken retrospectively on 13 cases of AF and seven cases of ameloblastic fibro-odontoma (AFO). Thirty-three complex odontomas and 33 compound odontomas were also included for comparative purpose. Relevant follow-up data were recorded and the literature was reviewed. RESULTS: The majority of patients with AF (nine cases, 69.2%) were over the age of 22 years with frequent involvement (76.9%) of the posterior mandible. Tumors recurred in four of 11 patients with follow-up information and two recurrent tumors showed malignant transformation. There was no case in this series that could be designated as the so-called ameloblastic fibrodentinoma, apart from one recurrent AF in which further maturation to form only tubular dentin materials was identified. AFO tended to occur at a younger age group with an average of 9.6 years. Recurrence was noted in two of five patients with follow-up data and both recurrent lesions showed limited growth potential and further maturation into a complex odontoma. Significant differences were noted in the age and site distribution between the complex and the compound odontomas. CONCLUSION: Whilst the majority, if not all, of AFs are true neoplasms with a potential to recur and/or of malignant transformation, some, especially those occurred during childhood, could represent the primitive stage of a developing odontoma. Our data also suggests that some AFOs are hamartomatous in nature, representing a stage preceding the complex odontoma.     

Assessment of growth potential by MIB-1 immunohistochemistry in ameloblastic fibroma and related lesions of the jaws compared with ameloblastic fibrosarcoma

Sano K, Yoshida S, Ninomiya H, Ikeda H, Ueno K, Sekine J, Iwamoto H, Uehara M, Inokuchi T: Assessment of growth potential by MIB-1 immunohistochemistry in ameloblastic fibroma and related lesions of the jaws compared with ameloblastic fibrosarcoma. J Oral Pathol Med 1998; 27: 59–63. © Munksgaard, 1998.
Specimens from two ameloblastic fibromas (including one recurrent case), two ameloblastic fibro-odontomas, and one ameloblastic fibrosarcoma were subjected to investigation by MIB-1 immunohistochemistry in order to elucidate the growth potential of these tumors. MIB-1 labeling indices in the epithelial component of these tumors ranged from 2.9 to 7.5%, whereas those in the mesenchymal component ranged from 1.5 to 13.5%. Of these, labeling indices in the mesenchymal component of the recurrent ameloblastic fibroma and ameloblastic fibrosarcoma were quite high. These findings suggest that evaluation of growth potential in ameloblastic fibroma and related lesions could be of help in understanding tumor aggressiveness and in selecting appropriate surgical procedures.     

成釉细胞纤维牙瘤的临床特点及治疗

成釉细胞纤维牙瘤是一种少见的牙源性肿瘤,多发生于20岁以下,男性多于女性,上下颌骨均可发生,多发生于下颌骨,生长缓慢,无自觉症状,常表现为颌面部的肿胀、牙齿迟萌。X线片常见单房改变,表现为边界清楚的囊性透射影,不易与牙源性肿瘤鉴别。组织学表现,软组织成分为牙源性上皮和胚胎性的结缔组织,类似成釉细胞纤维瘤的形态,硬组织成分为牙本质、釉质样组织,类似牙瘤。恶变可能性低,治疗方式为手术摘除,一般不易复发。该文结合我科收治的成釉细胞纤维牙瘤病例,探讨成釉细胞纤维牙瘤的临床特点及治疗与预后。     

Quantitative analysis of argyrophilic nucleolar organizer regions and epidermal growth factor receptor in ameloblastomas

OBJECTIVE: The aim of this study was to evaluate the proliferation activity by means of the quantification of the argyrophilic nucleolar organizer regions (AgNORs) and the patterns of expression of the epidermal growth factor receptor (EGFR) in ameloblastomas. METHOD: The methods of evaluation included the H/E stain for the morphologic analysis, the silver impregnation technique for quantification of the AgNORs and the immunohistochemical stain with anti-EGFR antibody in 11 cases of ameloblastoma. RESULTS: The results did not show a significant statistical difference as per quantification of the AgNORs. The expression of the EGFR on the epithelial islands of ameloblastoma was not uniform, and the location of the expression was also variable. The predominant expression was that of cytoplasm and the islands with an expression of membrane only were rare and generally smaller in size. CONCLUSION: The tumor presents an irregular growth. Smaller islands are associated with a higher proliferation activity and therefore could be responsible for tumor infiltration.     

PIGK与PCNA在成釉细胞瘤中的表达与意义

目的探讨PIGK与PCNA蛋白在成釉细胞瘤中的表达。方法采用HE染色与免疫组化染色检测45例成釉细胞瘤中PIGK与PCNA的表达,统计学分析染色指标与疾病病理分型的相关性及指标之间相关性。结果在成釉细胞瘤中,PIGK只在3例中呈现阳性表现,且与病理分型不相关(P>0.05),PCNA在所有成釉细胞瘤中均出现阳性表达,但也与病理分型不相关(P>0.05);由于病例数限制不认为PIGK与PCNA的表达存在相关性。结论 PIGK与PCNA的免疫组化染色结果与成釉细胞病理分型不存在相关性,两指标之间表达不存在相关性。     

Survivin蛋白在人成釉细胞瘤中的表达及意义

目的:探讨survivin在成釉细胞瘤中的表达及意义。方法:采用免疫组织化学S-P法检测70例成釉细胞瘤(ameloblastoma, AB)、 15例恶性AB、30例正常口腔黏膜中survivin的表达。采用SPLUS13.0软件包对数据进行统计学分析。结果:AB、恶性AB中survivin明显表达,恶性AB中阳性表达率最高,为100%,其次为AB(82.9%);正常口腔黏膜轻微表达,其阳性率为30%,各组间差异显著(P<0.05)。结论:AB中survivin高表达,且明显高于正常口腔黏膜。Survivin可能参与AB的发生与发展,AB的侵袭性增加和恶变与survivin的高表达相关。     

核仁组织区在Wistar大鼠腭黏膜癌变过程中表达的变化

目的:研究Wistar大鼠腭黏膜癌变过程中核仁组织区(NOR)的变化及与癌变趋势的关系。方法:通过化学诱导法建立大鼠口腔癌模型,采用银染核仁组织区法对7例正常黏膜和63例不同癌变发展阶段黏膜细胞的增殖状态进行检测。结果:随着异常增生程度和组织病理学分级的增加,AgNOR颗粒计数逐渐增多。单纯性增生、异常增生、原位癌、浸润性鳞癌与正常黏膜相比差异有统计学意义(P<0.05)。结论:AgNOR的表达在口腔黏膜癌变过程中逐渐增强。     

Evaluation of the nucleolar organizer region associated proteins in minor salivary gland tumors

Forty-three intraoral salivary gland tumors were studied to determine the value of the AgNOR technique in the assessment of these neoplasms. Well defined black dots were visible in the nucleii of all the specimens studied. The mean AgNOR count per nucleus for each tumor was calculated as follows: pleomorphic adenoma (n = 15) 1.52; Polymorphous low-grade adenocarcinoma (n = 12) 1.90; adenoid cystic carcinoma (n = 6) 2.92; mucoepidermoid carcinoma (n = 4) 1.93; carcinoma ex mixed tumor (n = 4) 2.05; undifferentiated carcinoma (n = 1) 3.13 and epithelial-myoepithelial carcinoma (n = 1) 2.23. The difference between the means of benign and malignant tumors (P less than 0.01) and polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma (P less than 0.01) were highly significant. The overlapping of the AgNOR count between various tumors prohibited the use of this technique as an absolute criterion in establishing a final diagnosis. It could however be used as a diagnostic aid in differentiating between salivary gland neoplasms.     

Immunohistochemical distribution of collagens type I, III, IV and VI, of undulin and of tenascin in oral fibrous hyperplasia

The distribution of collagens type I, IV and VI, of procollagen type III, of undulin and of tenascin was studied in 10 lesions which were clinically and histologically diagnosed as localized oral fibrous hyperplasias. The immunohistochemical distribution of these proteins was similar to that observed for normal oral mucosa. Undulin showed a pattern of parallel fibers throughout. Collagen type VI was pronounced in the subepithelial connective tissue, whereas the collagen fiber bundles were equally reactive for collagens type I and III. Tenascin was observed close to the subepithelial basement membrane and in proximity to collagen fiber bundles in the upper connective tissue. The present findings indicate that oral fibrous hyperplasias that are probably caused by inflammation or chronic irritation show the differentiated and ordered pattern of extracellular matrix proteins characteristic of normal oral mucosa.     

扭曲基因在成釉细胞瘤中的表达及其意义

目的 探讨扭曲基因(twist)在人成釉细胞瘤CAME)中的表达及其意义.方法 用免疫组化法检测40例AME标本和10例根尖囊肿标本中Twist的表达情况;用蛋白质印迹技术检测5例AME和1例根尖囊肿组织中Twist的表达情况,分析其临床病理意义.结果 Twist在AME和根尖囊肿组织中的阳性率分别为75.0%和20.0%,在AME中的表达明显高于根尖囊肿组织(P＜0.05);Twist在一般型AME中的表达水平明显高于单囊型(P＜0.05).与根尖囊肿组织相比较,Twist在AME中表达明显上调(P＜0.05),但单囊型AME与根尖囊肿相比较差异无统计学意义(P＞0.05).结论 Twist在AME中高表达可能与AME的发生发展密切相关.     

Ameloblastic carcinoma containing melanocyte and melanin pigment in the mandible: a case report and review of the literature

A case of ameloblastic carcinoma containing melanocyte and melanin in a 66-year-old male with swelling and an ulcerating firm mass in the left submandibular region is presented. The diagnosis was confirmed by biopsy. The current histopathological diagnosis and management are discussed.