Section of Oral Pathology, Tokyo Medical and Dental University, Tokyo, Japan.
Hum Pathol. 2010 Dec;41(12):1718-25. doi: 10.1016/j.humpath.2010.05.007.
Keratocystic odontogenic tumor is a cystic lesion that behaves more aggressively than other jaw cysts. One of its characteristic histologic features is a parakeratinized uniform layer of lining epithelium. A jaw cyst lined with orthokeratinized epithelium is called an orthokeratinized odontogenic cyst. These keratinized jaw cysts are thought to be separate entities, although their histopathogenesis has not been fully assessed. To better understand these lesions, we performed comprehensive immunohistochemical profiling of the keratin expression of each. Orthokeratinized odontogenic cysts expressed keratin 1, keratin 2, keratin 10, and loricrin, suggesting differentiation toward normal epidermis. Keratocystic odontogenic tumors expressed keratin 4, keratin 13, keratin 17, and keratin 19, which is a unique expression pattern reminiscent of a mucosal squamous epithelium and an epithelial appendage. In neonatal rat tooth germ, cells strongly positive for keratin 17 and keratin 19 were observed, specifically in the dental lamina, implying the origin of keratocystic odontogenic tumor. GLI2, a downstream effector of hedgehog signaling, was significantly expressed in keratocystic odontogenic tumor and basal cell carcinoma, accompanied with robust expression of keratin 17, mammalian target of rapamycin, and BCL2. The expression of these GLI2- or keratin 17-related factors was not significantly observed in orthokeratinized odontogenic cysts. These findings provide evidence to support the viewpoint that keratocystic odontogenic tumor and orthokeratinized odontogenic cyst are separate entities, and furthermore suggest their characteristic histology, pathogenesis, and biological behaviors.
牙源性角化囊性瘤是一种囊性病变，其行为比其他颌骨囊肿更具侵袭性。其特征性组织学特征之一是具有一层均匀的角化层衬里上皮。由正角化上皮衬里的颌骨囊肿称为正角化牙源性囊肿。这些角化性颌骨囊肿被认为是独立的实体，尽管其组织发生尚未得到充分评估。为了更好地理解这些病变，我们对每种病变的角蛋白表达进行了全面的免疫组织化学分析。正角化牙源性囊肿表达角蛋白 1、角蛋白 2、角蛋白 10 和兜甲蛋白，提示向正常表皮分化。牙源性角化囊性瘤表达角蛋白 4、角蛋白 13、角蛋白 17 和角蛋白 19，这是一种独特的表达模式，类似于黏膜鳞状上皮和上皮附属物。在新生大鼠牙胚中，观察到角蛋白 17 和角蛋白 19 强阳性的细胞，特别是在牙板中，提示牙源性角化囊性瘤的起源。 hedgehog 信号通路的下游效应物 GLI2 在牙源性角化囊性瘤和基底细胞癌中显著表达，同时伴有角蛋白 17、哺乳动物雷帕霉素靶蛋白和 BCL2 的强烈表达。在正角化牙源性囊肿中未观察到这些 GLI2 或角蛋白 17 相关因子的显著表达。这些发现为支持牙源性角化囊性瘤和正角化牙源性囊肿是独立实体的观点提供了证据，并进一步表明它们具有特征性的组织学、发病机制和生物学行为。
