2022年世界卫生组织指南头颈部肿瘤分类的解读：牙源性和颌面部骨肿瘤

世界卫生组织出版的《头颈部肿瘤分类》是口腔颌面外科、口腔病理科医生权威的参考资料。随着近年来分子生物学的飞速发展和诊疗技术的不断提升,作为头颈部肿瘤中一类重要疾病——牙源性和颌面骨肿瘤,它在已经出版的2022年第5版中出现了许多新变化。本文主要与2017年第4版的指南比较,重点阐述了第5版在新分类、新病种和新遗传分子学改变这三方面的内容,以期辅助临床诊疗。     

Peripheral calcifying odontogenic cyst

BACKGROUND: Calcifying odontogenic cyst (COC) is a rare lesion representing about 1% of jaw cysts. It may occur in a central (intraosseous) or peripheral (extraosseous) location. METHOD: A case of peripheral COC located on the gingiva, appearing as a painless, circumscribed, pink nodule has been reported. RESULTS: Peripheral, in contrast to central, COC tends to affect older patients. Peripheral COC is a less aggressive lesion than the central counterpart, and a simple excision biopsy is curative. CONCLUSION: The histological finding of a keratinized epithelium rich in ghost cells has helped in making the diagnosis.     

Infrequent clinicopathological findings in 108 ameloblastomas

One hundred and eight ameloblastomas diagnosed in a rural black Africa population were analysed for clinicopathologic findings other than those classically described. One patient had a polycystic ameloblastoma adjacent to an ameloblastic fibroma. Two other polycystic ameloblastomas showed aneurysmal bone cyst formation and one mandibular tumour was diagnosed as a keratoameloblastoma. Microscopic changes resembling an adenomatoid odontogenic tumour were present in association with two unicystic ameloblastomas and a HPV18-positive verrucous lesion occurred in the lining of a cystic space of a polycystic ameloblastoma. Two ameloblastomas contained eosinophilic granules in all tumor cells and melanocytes were diffusely present in another. One case exhibited a focus of mucous cell metaplasia. Two polycystic ameloblastomas showed diffuse interstitial ossification. One mandibular tumor was diagnosed as a desmoplastic ameloblastoma and another as an odontoameloblastoma. This study demonstrated that although ameloblastomas are regarded as a fairly homogeneous group of neoplasms, detailed investigations prove clinicopathologic diversity in a significant number of lesions.     

Spindle-cell hemangioendothelioma of the oral cavity. A case report

We describe a vascular tumor classified as SCH by histological criteria that was found in the mandibular-buccal fold of a 12-year-old girl. Microscopically, the lesion consisted of thin-walled cavernous spaces containing thrombi and phleboliths, and cellular areas composed of spindle-shaped, epithelioid and vacuolated cells. Immunohistochemically, the endothelial vascular lining was highly reactive with HAM56 antibody, while variable reactivity was observed for factor VIII-associated antigen. All cell types were positive for vimentin and anti-PCNA stained less than 3% of the tumor cells. This is the first report of SCH in the oral cavity.     

Peripheral dentinogenic ghost cell tumor

A case of dentinogenic ghost cell tumor, that has originated peripherally in the jaw, is presented and the literature reviewed with particular reference to the origin of the tumor. The total number of central and peripheral cases reported in the English literature is 10 and although mucosal infiltration is common, peripheral origin of the neoplasm could be verified in only 3 cases.     

腮腺区软组织肿块B超显象的临床意义

通过对60例常见腮腺区软组织肿块的B超显象辅助诊断，并将具有与标本肉眼观察及光镜下病理特点作比较分析，说明B超检查对临床上腮腺区肿块的诊断具有指导意义。涎腺肿块中肿瘤约占80％，其中主要发生在浅叶，适宜进行B超检查，在确定腮腺区占位性病变方面B超检查应为首选的检查方法。     

壁性成釉细胞瘤术后追踪观察

目的 研究影响壁性成釉细胞瘤术后复发因素及刮治术复发病例观察。方法 对４４例壁性成釉细胞瘤患者术后观察１年～２５年４个月,平均５年７个月。结果 ①刮治术后复发（８／３５）多于根治术后复发（１／９）;②肿瘤生长呈壁内型（４／７）和混合型（３／４）刮治术后复发明显多于腔内型术后复发（０／１５）;③蜂房型（３／３）刮治术后复发明显多于单房型（１／２０）;④刮治术后２年内肿瘤易出现复发（７次／５例）;⑤刮治术后复发者再次刮治仍有再复发倾向。结论 ①Ｘ线表现呈蜂房型者应做根治疗手术;②刮治术后病理呈壁内型或混合型生长方式者应重视定期复查;③刮主后病例应常规定期复查５年。     

Molecular alterations in odontogenic keratocysts as potential therapeutic targets

The odontogenic keratocyst (OKC) is a cystic lesion, lined by uniformly thickened parakeratinized epithelium. Some lesions are large and tend to recur after surgical treatment. The neoplastic nature of OKCs remains a matter of dispute. It is known that some sporadic OKCs harbor PTCH1 mutations, and via the dissection of cyst epithelium, these mutations were demonstrated to occur much more frequently than previously thought. In addition to the classical PTCH1 mutations, Hedgehog pathway disturbance and Bcl‐2 protein overexpression, as detected via genome‐wide expression analysis of OKCs, have been published. Changes in DNA methylation patterns and alterations in microRNA expression levels have recently been reported in these lesions. We reviewed the molecular mechanisms that underlie the pathogenesis of OKCs as described over the past few years and explored the molecular alterations that can be therapeutically targeted.     

Odontogenic tumors: analysis of 289 Nigerian cases

Two hundred and eighty-nine cases of odontogenic tumors that accumulated in the files of the biopsy service of the Lagos University Teaching Hospital during a period of 21 years were analysed and categorised according to the most recent WHO classification of odontogenic tumors. Odontogenic tumors constituted 19% of all oral/jaw tumors and tumor-like lesions. Ameloblastoma, which accounted for 58.5% of odontogenic tumors in the series, was the most common, and showed a predilection for males and the posterior mandible. 94.8% of odontogenic tumors were benign, while malignant odontogenic tumors accounted for 5.2%. Odontogenic carcinoma was the most prevalent malignant odontogenic tumor; it showed a predilection for the mandible and occurred at a mean age of 37 years.     

821例牙源性肿瘤及相关病变统计分析

按世界卫生组织（ＷＨＯ）１９９２年新分类标准对８２１例牙源性肿瘤重新诊断归类，统计分析不同类型的构成比例、年龄、性别及部位分布。结果显示最常见的牙源性肿瘤是造釉细胞瘤（５３．８％），与北美地区报道牙瘤（５１．４～６７．０％）常见结果不一致。男性患者略多于女性（１．３：１），高发年龄为１０～３９岁（６９．ｏ％）。下颌骨多于上颌骨（３．１：１），且以下颌磨牙区和下颌角区最常见（４３．２％），其中造釉细胞瘤下颌骨与上颌骨之比为１２．７：１，远高于北美地区的报道（２．５：１）。     

Distribution of oral tumors in Nigerian children based on biopsy materials examined over an 11-year period

A survey of biopsied lesions of patients aged 0-16 yr who presented with oral swellings at the Lagos University Teaching Hospital over a period of 11 yr was conducted to determine the pattern of presentation of these lesions in 203 Nigerian children, 123 boys and 80 girls. 21% of the lesions were fibro-osseous lesions. There were more non-odontogenic than odontogenic tumors and very few salivary gland tumors.     

Central odontogenic fibroma current concepts

The author reviews current knowledge concerning the central odontogenic fibroma, which at present is incompletely understood, and reaches the following conclusions. 1) The separation of this lesion into simple and WHO types remains valid because they exhibit different histologic features. However, more care should be taken in rendering the diagnosis of the WHO type than in the past; unlike the simple type, it is a fibroblastic lesion. 2) Complex central odontogenic fibroma is a more appropriate term than the WHO type because the WHO does not use the latter term in its 1992 manual. 3) The microscopic distinction of simple odontogenic fibroma from desmoplastic fibroma remains difficult in some cases. 4) The granular cell odontogenic tumor, which has sometimes been referred to as a type of odontogenic fibroma, is a separate entity, although some simple odontogenic fibromas exhibit scattered granular cells. 5) The separation of lesions that have been reported recently as odontogenic fibromas with giant cell reactions from central giant cell granulomas that exhibit foci of odontogenic epithelium requires further study.     

Epulides in the dog: a review

This article is based on a review of the literature and the study of pathology sections obtained from various veterinary pathology laboratories. Epulis is a non-specific, clinical designation for a localized, exophytic growth on the gingiva. Four reactive epulides occur in human beings, namely focal fibrous hyperplasia (fibrous epulis). pyogenic granuloma. peripheral giant cell granuloma (giant cell epulis. and peripheral ossifying fibroma (calcifying fibrous epulisl). The first three also occur in dogs but only focal fibrous hyperplasia appears to be common. The peripheral ossifying fibroma has not yet been reported in dogs. Odontogenic tumors occurring on the gingiva (i.e., as epulides) are referred to as peripheral odontogenic tumors. Three types have been reported in dogs. One, the common fibromatous epulis. is equivalent to the rare peripheral odontogenic fibroma in human beings. Another, the acanthomatous epulis. appears to be a form of ameloblastoma but differs from the peripheral ameloblastoma in human beings in that it invades bone; its biological behavior is therefore that of the human intraosseous ameloblastoma. The third, a rare lesion, has been referred to in the veterinary literature as a calcifying epithelial odontogenic tumor, although it is not the canine counterpart of the human CEOT The term, amyloid-producing odontogenic tumor , has been suggested as being appropriate for this lesion.     

Expression of hMSH2 and hMLH1 proteins of the human DNA mismatch repair system in ameloblastoma

The human DNA mismatch repair (hMMR) system plays an important role in reducing mutation and maintaining genomic stability. The MMR system in human cells is composed of at least six genes (hMSH2, hMLH1, hMSH3, hPMS1, hPMS2 and GTBP/hMSH6). In particular, hMSH2 and hMLH1 are expressed in human cells that are undergoing rapid renewal; their reduced expression has been reported in several tumors. We examined the protein expression pattern of hMSH2 and hMLH1 by immunohistochemistry in 25 ameloblastomas. All ameloblastomas expressed hMSH2 and hMLH1 proteins in the outer layer of epithelial cells. The localization of the staining was exclusively nuclear. These data suggest that the development and progression of these tumors do not depend on a defect in the hMMR system.