摘要国内首次报道一例良性毛囊性肿瘤——毛胚瘤.患者男,48岁,前胸壁无症状皮下结节10年.组织学显示肿瘤位于真皮,境界清楚,边缘有纤维性假包膜,瘤团由结节和囊肿构成,大多数结节显示中央透明细胞呈同心圆分布,周围嗜碱性细胞呈栅栏状排列.可见肿瘤向毛球、内毛根鞘、外毛根鞘和毛囊漏斗部分化.免疫组化显示,肿瘤细胞表达角蛋白AE1/AE3、CK5/6和CK17,不表达CK7或CK20.中央透明细胞和周边栅栏状细胞显示完全不同的免疫组化表达方式.结合组织学和免疫组化改变诊断毛胚瘤.

abstractsA case of benign follicular neoplasm-trichogerminoma-is reported.A 48-year-old man presented with a 10-year history of asymptomatic subcutaneous nodule in the chest.Histological examination revealed a well-circumscribed lesion composed of variously sized lobuli and cysts in the deep dermis and separated from the surrounding tissue by a fibrous capsule.Most lobuli consisted of concentrically arranged clear cells in the central area and basophilic cells in a palisade arrangement in the peripheral area.The tumor cells displayed a multi-directional differentiation toward hair bulb,inner root sheath,outer root sheath and infundibulum of hair follicles.Immunohistochemically,the tumor cells expressed AE1/AE3,CK5/6 and CK17,but were negative for CK20 or CK7.There was a sharp contrast in immunohistochemical findings between the central clear cells and peripheral basophilic cells.Based on the histological and immunohistochemical features,a diagnosis of trichogerminoma was made.