Abstract：
Granular cell ameloblastoma is classified as a histological subtype of solid/multicystic ameloblastoma. Usual granular cell ameloblastoma is histologically characterized by granular changes of stellate-like cells located in the inner portion of the epithelial follicles. Here we report a case of another type of granular cell ameloblastoma, showing predominant anastomosing double-stranded trabeculae of granular cells. This type of granular cell ameloblastoma is extremely rare, and the World Health Organization classification does not contain the entity. We tentatively termed it \'anastomosing granular cell ameloblastoma\' in this report. The present case suggests the importance of differential diagnosis because the histology of \'anastomosing granular cell ameloblastoma\' resembles that of salivary gland oncocytoma rather than that of usual granular cell ameloblastoma. The trabeculae observed in our case continued to the peripheral cells of a small amount of epithelial sheets of plexiform ameloblastoma, and the tumor cells were positive for CK19, which is regarded as an immunohistochemical marker of odontogenic epithelium. Similar to usual granular cell ameloblastoma, the tumor cells had CD68-positive granules. For precise diagnosis of this condition, immunohistochemistry using CK19 and CD68, as well as detailed histological observation, are recommended.
摘要：
颗粒细胞成釉细胞瘤被分类为实体/多囊性成釉细胞瘤的组织学亚型。通常的颗粒细胞成釉细胞瘤的组织学特征是位于上皮滤泡内部的星状样细胞的颗粒状变化。在这里，我们报告了另一种类型的颗粒细胞成釉细胞瘤，显示主要吻合颗粒细胞的双链小梁。这种颗粒细胞成釉细胞瘤极为罕见，世界卫生组织的分类不包含该实体。在本报告中，我们暂时将其称为“吻合颗粒细胞成釉细胞瘤”。本病例提示鉴别诊断的重要性，因为“吻合性颗粒细胞成釉细胞瘤”的组织学类似于唾液腺嗜酸细胞瘤，而不是通常的颗粒细胞成釉细胞瘤。在我们的病例中观察到的小梁继续到丛状成釉细胞瘤的少量上皮片的外周细胞，肿瘤细胞CK19阳性，CK19被认为是牙源性上皮的免疫组织化学标记。类似于常见的颗粒细胞成釉细胞瘤，肿瘤细胞有CD68阳性颗粒。为了精确诊断这种情况，使用CK19和CD68进行免疫组织化学，以及详细的组织学观察，被推荐。
