Differences in collagen fibres in the capsule walls of parakeratinized and orthokeratinized odontogenic cysts

Epithelial-mesenchymal interactions are thought to play an important role in the pathogenesis of odontogenic lesions. Keratocystic odontogenic tumour (KCOT) is a benign cystic neoplasm with a characteristic parakeratinized epithelial lining, which differs histologically and behaviourally from the so-called orthokeratinized odontogenic cyst (OOC). The purpose of this study was to investigate the differences in collagen fibres within the fibrous tissue walls of KCOT and OOC. Formalin-fixed paraffin-embedded tissue samples from 15 cases of KCOT and 15 cases of OOC were collected. Paraffin sections were stained with picrosirius red and observed under a standard light microscope using optical polarization. Unicystic ameloblastoma (UA, 15 cases) and subcutaneous epidermoid cysts (EC, 15 cases) were included in the study for comparative purposes. Significant difference was detected between the polarization colours in the fibrous tissue walls of KCOT and OOC (P < 0.05), whilst no significant differences were found between KCOT and UA and between OOC and EC (P > 0.05). The stromal collagen fibres of KCOT were different from those of OOC, but similar to those of UA, which suggests that the stroma of KOCT may play an important role in determining the neoplastic behaviour of the lesion through epithelial-mesenchymal interaction.     

Collagen fibres in the wall of odontogenic keratocysts: a study with picrosirius red and polarizing microscopy

The collagen in the walls of 15 keratocysts was studied histochemically by staining sections with picrosirius red and examining them with polarizing microscopy. This was compared to 15 cases of dentigerous cyst and 15 cases of radicular cyst. Polarization colours of the collagen fibres were recorded according to their width. No differences were found between the polarization colours of thin fibres (<0.8 microm) in all three lesions; the polarization colours of thick fibres (1.6-2.4 microm) in keratocysts were significantly more greenish-yellow when compared with those of dentigerous cysts and radicular cysts. The staining of the collagen fibres in the keratocysts is similar to that reported in odontogenic neoplasms, which suggests that the stroma of keratocysts could be regarded not just as a structural support of the cyst wall, but as playing a part in the neoplastic behaviour of the cyst.     

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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。     

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.     

Expression of basement membrane components in odontogenic cysts

OBJECTIVE: To compare the expression of basement membrane components (BMCs), including laminins 1 and 5, collagen type IV, and fibronectin in odontogenic keratocysts (OKCs) with dentigerous cysts (DCs) and radicular cysts (RCs). MATERIALS AND METHODS: Basement membrane components were analysed in 20 OKCs, 20 DCs and 20 RCs using an immunohistochemical technique. RESULTS: Odontogenic keratocysts, DCs and RCs showed positive reaction to all BMCs studied, with different distributions and intensity. OKCs showed continuous linear deposits for laminins 1 and 5 but two staining patterns (continuous and discontinuous) for collagen type IV and fibronectin. DCs exhibited continuous linear deposits for laminins 1 and 5 and collagen type IV but a discontinuous linear deposit for fibronectin. RCs displayed similar results to DCs for laminin 1, collagen type IV and fibronectin. Laminin 5 in RCs had two staining patterns. Constant results in all cysts were strong intensity for laminin 1 and moderate intensity for laminin 5. CONCLUSIONS: Substantial differences in the expression of BMCs among studied cysts were not observed, suggesting that the separation of the epithelial lining in OKCs is not associated with the existence of these proteins.     

Expression of transforming growth factor-beta 1 (TGF-beta 1) in odontogenic cysts

AIM: To evaluate the positivity to transforming growth factor-beta 1 (TGF-beta 1) in different types of odontogenic cysts. METHODOLOGY: A total of 30 radicular cysts (RCs), 27 follicular cysts (FCs) and 28 odontogenic keratocysts (OKCs) were evaluated for immunohistochemical analysis of TGF-beta 1. TGF-beta 1 was evaluated in blood vessels, stromal cells (fibroblasts) and pluristratified squamous epithelium. TGF-beta 1 expression was determined by evaluating the number of positive elements. TGF-beta 1 expression was determined by evaluating 1000 cells in the pluristratified squamous epithelium (500 in the basal and parabasal layers, and 500 in the superficial layer) and 500 cells (the fibroblasts in the stroma) for each specimen, and counting the number of positive cells. The number of positive vessels was evaluated in 10 high power fields (HPF). The Chi-square test was used to evaluate differences between the two groups (RC + FC and OKC). A P-value <0.05 was considered to indicate statistical significance. RESULTS: A higher and statistically significant positivity was found in the basal-suprabasal epithelial layers (P=0.0011), superficial epithelium (P=0.053) and stromal cells (P=0.0002) of orthokeratotic and parakeratotic OKC as compared with RC and FC. CONCLUSIONS: These differences suggest that control of the cell cycle may be abnormal in orthokeratotic OKCs. These OKCs may have an intrinsic growth potential not present in other cyst types.     

Mast cells in human odontogenic cysts

Mast cells have been shown to be present in substantial numbers in both nonkeratinizing and keratinizing odontogenic cysts and could be seen in the connective tissue capsule and the epithelial lining. Within the cyst capsule, mast cells were more prevalent just beneath the epithelium than in deeper areas. This distribution pattern for mast cells is in accord with the histochemical picture for heparin staining in odontogenic cysts. In the non-keratinizing cysts, there appeared to be some trend towards mast cells being associated with increasing inflammation but not in the odontogenic keratocyst. No evidence could be found for distinct mast cell subpopulations in odontogenic cysts. The presence of mast cells in odontogenic cyst could contribute to their pathogenesis in several ways.     

Histochemical studies on cholesterol formation in odontogenic cysts and granulomas

abstract — A histologic and histochemical study was made of 45 odontogenic periapical cysts and granulomas with cholesterol formation. The specimens were transported in Histocon® solution and sectioned by cold microtome. This technique permits the preservation of the lipids and rertains the enzyme activities in the cells. Cholesterol crystals seemed to be formed in disintegrating clots of red blood corpuscles in congested capillaries of the inflammatory areas. The pericytes of the vessel walls changed their enzyme activities, indicating increased lysosomal functions, and eventually formed giant cells with tissue degrading properties.     

Lipids in the walls and contents of jaw cysts

abstract – The amount and composition of lipid in 129 walls of jaw cyst and 18 pieces of cyst contents was determined by thin-layer chromatography. The proportions of the fractions (i.e. phospholipid, free cholesterol, cholesteryl ester, triglyceride, free fatty acids) were compared with corresponding values (collected from the literature) from the superficial layers of normal and atherosclerotic aortas. The amounts of total lipid and of the fractions were comparable. Concomitant with an increasing amount of lipid, there was a rise in the ratio: total cholesterol/phospholipid. In the aortic lesions this increase of cholesterol was due to a rise in the fraction of cholesteryl ester. In the cyst material, the increase was due to a rise in the free cholesterol. A possible explanation is discussed.     

开窗减压配合囊肿塞治疗青少年颌骨囊肿的疗效分析

目的 分析开窗减压术配合囊肿塞治疗青少年颌骨囊肿的疗效。方法 收集整理2009年8月—2011年8月于我院口腔颌面外科行开窗减压术的青少年（13~20岁）颌骨囊肿患者（15例26个囊肿）病例资料,统计分析疗效。结果 15例患者中8例患者（53.3%）开窗效果良好,6例患者（40.0%）效果中等,1例患者（6.7%）效果不佳。93颗受累恒牙,70颗（75.3%）得以保存。结论 开窗减压术配合囊肿塞是一种有效的保守治疗青少年颌骨囊肿的方法。     

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.     

Prevalence of developmental odontogenic cysts in children and adolescents with emphasis on dentigerous cyst and odontogenic keratocyst (keratocystic odontogenic tumor)

Objective. To investigate the incidence and prevalence of developmental odontogenic cysts in children and adolescents and compare the features of the two most common types, dentigerous cyst and keratocystic odontogenic tumor (KCOT). Study design. A retrospective review in a series of 369 patients with all histological diagnoses of developmental odontogenic cysts in children (≤12 years) and adolescents (13–18 years) was conducted. Results. Among these, 361 (97.8%) patients were diagnosed as dentigerous cyst (n = 281) and KCOT (n = 80), with the male-to-female ratios of dentigerous cyst and KCOT both being 2:1. The average age of the patients with KCOT was older than that of those with dentigerous cyst (14.7 years vs 11.8 years, p < 0.001). Dentigerous cyst (59.1%) was more common in children, but KCOT (78.8%) was more common in adolescents (p < 0.001). Dentigerous cyst (57.6%) predominantly located on the maxilla, but KCOT (60.3%) predominantly located on the mandible (p = 0.010). Conclusions. Adolescent patients with lesions located on the mandible would favor KCOT over dentigerous cyst. This study aids in better knowledge of the prevalence of developmental odontogenic cysts in a large pediatric population, and shows that a well-supported early diagnosis is indispensable for a more adequate treatment.     

Blood group antigens A and B in ameloblastomas, odontogenic keratocysts and non-keratinizing cysts

abstract — The expression of blood group antigens A and B has been studied in 8 ameloblastomas, 16 odontogenic keratocysts from patients with basal cell nevus syndrome, 11 odontogenic keratocysts from patients without the syndrome, and 12 non-keratinizing odontogenic cysts, using a double layer immunofluorescence staining technique. The amount of antigen in the lesions was compared with the content of antigen in normal buccal mucosa from each patient. All ameloblastomas reacted negatively, three cysts from the patients with the basal cell nevus syndrome reacted negatively, and the odontogenic keratocysts from patients without the syndrome as well as the non-keratinizing odontogenic cysts all gave a positive reaction.     

囊肿塞在颌骨囊肿开窗减压术中的应用

囊肿塞是颌骨囊肿进行开窗减压术治疗中常用的辅助治疗器具,近年来,随着材料和技术的发展,不同形式的囊肿塞层出不穷。本文回顾了目前临床常见囊肿塞的种类、制作方法及其适应证,探讨了各类囊肿塞在制作及应用过程中的优缺点。     

p53 and MDM2 expression in odontogenic cysts and tumours

OBJECTIVE: The aim of this report was to assess p53 and MDM2 expression in odontogenic cysts and tumours, as they are known to play important roles in cell proliferation and tumorigenesis. MATERIALS AND METHODS: The expression of p53 and MDM2 proteins was determined immunohistochemically in 51 formalin-fixed, paraffin embedded specimens of odontogenic cysts and tumours.RESULTS: No positivity to p53 was found in the cases studied. MDM2 expression in ameloblastoma was higher than in radicular cysts, but lower than that observed in odontogenic keratocysts. No difference was observed between MDM2 expression in radicular cyst and adenomatoid odontogenic tumour. The clear-cell odontogenic ameloblastoma presented strong immunoreaction to this antigen.CONCLUSIONS: The results suggest that MDM2 overexpression may be involved in the pathogenesis of some odontogenic 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.