恶性增生性甲外毛根鞘样囊肿

Malignant proliferating onycholemmal cyst

报告1例恶性增生性甲外毛根鞘样囊肿。患者男,78岁。右手拇指指甲增厚、破溃30年,伴疼痛。组织病理检查见甲床下方大量囊肿样的肿瘤细胞团块,瘤细胞为鳞状上皮,异形性明显,中央可见毛鞘样角化,未见颗粒层,可见透明细胞,瘤细胞未侵入指骨。免疫组化结果显示肿瘤细胞CK1阳性,CK6阳性,CK10部分阳性,CK7阴性、CK15阴性、Ki-67增殖指数约20%。结合临床、组织病理及免疫组化结果诊断为恶性增生性甲外毛根鞘样囊肿。

To report a case of malignant proliferating onycholemmal cyst. A 78-year-old male presented with 30-year histo- ry of thickening and ulceration on his right thumb nail with pain. Histopathological examination showed small keratinous cysts with clear cells and squamous epithelial cells, abrupt central keratinizafion~ and of solid nests and strands of atypical ker- atinocytes without penetrating the phalangeal bone below the nail bed, Immunohistochemically the neoplastic cells were posi- tive for CK1, CK6 and partial positive for CK10, negative for CK7 and CK15, and Fd67 proliferation index20%. According to the clinical, histopathologic and immunohistopathologieal findings, the diagnosis of malignant proliferating onycholemmal cyst was made.