Abstract: 【Abstract】 Objective To analyze the disease constitution, accuracy of clinical and pathological diagnoses of skin biopsy samples in Peking Union Medical College Hospital. Methods A total of 29 987 patients subjected to skin biopsy were collected from Department of Dermatology, Peking Union Medical College Hospital from June 2010 to November 2018, and clinical and histopathological diagnoses of these skin biopsy samples were analyzed retrospectively. Results According to the results of histopathological diagnosis, confirmed diagnoses of these patients could be classified into 33 categories and 242 kinds. Common disease categories included epidermal tumors （2 931 cases, 9.77%）, connective tissue diseases （2 809 cases, 9.37%）, melanocytic tumors （2 078 cases, 6.93%）, erythematous scaly pustular dermatoses （1 376 cases, 4.59%）, lichenoid dermatoses （1 291cases, 4.31%）, allergic or eczematous skin diseases （1 282 cases, 4.28%）and infectious skin diseases （1 156 cases, 3.86%）. Common skin diseases included scleroderma （1 887 cases, 6.29%）, pigmented nevus （1 755 cases, 5.85%）, seborrheic keratosis （1 136 cases, 3.79%）, eczema （1 089 cases, 3.63%）, psoriasis （881 cases, 2.94%）, lichen planus （867 cases, 2.89%）, lupus erythematosus （638 cases, 2.13%）, pemphigus （549 cases, 1.83%）, and basal cell carcinoma （501 cases, 1.67%）. Poor consistency was observed between clinical diagnosis and histopathological diagnosis of lichen planus, bullous pemphigoid, granuloma annulare and hypereosinophilic dermatitis. Conclusions Common disease categories of the skin biopsy samples in Peking Union Medical College Hospital were epidermal tumors, connective tissue diseases, melanocytic tumors, erythematous scaly pustular dermatoses, lichenoid dermatoses, and allergic or eczematous skin diseases. Poor consistency was observed between clinical and pathological diagnosis in some skin diseases, and understanding of these diseases should be improved.

Key words: Biopsy, Connective tissue diseases, Nevi and melanomas, Skin diseases, papulosquamous, Lichenoid eruptions, Skin diseases, eczematous