Abstract:

Objective To investigate the clinical and histological characteristics of trichilemmal carcinoma（TLC）. Methods A clinicopathological analysis of 13 cases of TLC was carried out. Results There were 9 males and 4 females among the 13 patients with TLC who were aged from 34 to 87 years （mean: 70 years）. Clinically, the tumor presented as an exophytic mass; histologically, it was characterized by the proliferation of epithelial cells and keratinization of outer root sheath. Cytologically atypical clear cells predominated in the tumor tissue. Microscopy revealed different growth patterns of tumor cells, which included solid growth pattern, tobular pattern and trabecular pattern. Periodic acid Schiff （PAS） stain demonstrated clear cells in all the tumor tissues from the 13 patients. Immunohistochemistry was performed in tissue samples from 6 patients, and showed that these samples were positive to high molecular weight cytokeratin （CK-HMW） and epithelial membrane antigen （EMA）, but negative to carcinomebrynic antigen （CEA）, S-100, cytokeratin 8 （CK8）and epithelial antigen（Ber-Ep4）. Follow-up over 4 months to 5 years revealed neither recurrence nor metastasis in 9 cases. Conclusions TLC is a low-grade malignancy of skin adnexal tumor without distinctive clinical features, and should be differentiated from other malignant clear cell tumors of the skin.

Key words: Clinicopathology, diffierential diagnosis