外毛根鞘癌

Tricholemmal carcinoma

报告1例外毛根鞘癌。患者女,84岁。右侧面部出现肿块半年,增大、破溃,大小约3 cm×3 cm。皮损组织病理检查示呈小叶状增生且与表皮相连的肿瘤组织。部分肿瘤组织显示外毛根鞘角化。该肿瘤组织主要由内含透明细胞质之非典型大型细胞所组成,免疫组化染色显示角蛋白单克隆抗体(AE1/AE3)阳性,过碘酸-希夫染色(PAS)阳性,上皮膜抗原(EMA)阳性,S-100蛋白(S-100)阴性,平滑肌抗体(SMA)阴性,细胞角蛋白7(CK-7)阴性,临床诊断为外毛根鞘癌。建议患者行局部肿瘤切除。

An 84-year-old woman complained with a tumor on her right cheek for half a year. The tumor increased to 3 cm× 3 cm in size and became ulcerative. Histopathological examination revealed that tumor cells showed lobular proliferations connected with the epidermis. Tumor nests were mostly composed of large atypical ceils with clear cytoplasm which was AE1/ AE3-positive, PAS-positive, EMA-positive, S-100-negtive, SMA-negative, CK-7-negtive. Some of the nests showed tricholemmal-type keratinization. Tricholemmal carcinoma was established. This patient was suggested to take local surgical excision. Although the histological pictures suggest a high-grade malignant neoplasm, tricholemmal carcinoma has an indolent course. Local recurrence or distant metastases has been observed rarely. The correct diagnosis of this tumor allows its distinction from other clear cell carcinoma and prevents unnecessary radical procedures.