Abstract: Wang Zhiwei, Li Weiren, Liu Li, Yan Xiaoling, Zheng Deyi, Wang Yi, Du Jiao Guizhou Medical University, Guiyang 550004, China （Wang ZW）; Department of Burns and Plastic Surgery, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China （Li WR, Liu L, Yan XL）; Department of Burns and Plastic Surgery, Guizhou Provincial People′s Hospital, Guiyang 550002, China （Zheng DY, Wang Y, Du J） Corresponding authors: Li Weiren, Email: gz_lwr@163.com; Zheng Deyi, Email: deyizheng@126.com 【Abstract】 Objective To investigate clinicopathological features, diagnosis and treatment of cutaneous Merkel cell carcinoma （MCC）. Methods CNKI, Wanfang, Vip databases were searched for reported domestic cases of MCC from January 1, 1986 to October 1, 2017, and clinical data were collected, and retrospectively analyzed and summarized. Results During 31 years between 1986 and 2017, a total of 171 domestic cases of MCC were reported. There were 78 males and 93 females, and the ratio of male to female was 1∶1.19. Of the 171 patients, 136 （79.5%） were aged more than 50 years, and lesions mostly occurred on the head and face or extremities in 139 （81.3%） patients. Clinically, 149 （87.1%） patients were misdiagnosed as tumor of unknown origin （89 cases, 52%）, malignant lymphoma（34 cases, 19.9%）, benign tumors （15 cases, 8.8%） or non-tumor diseases （11 cases, 6.4%）. As for clinical stage, 84 （49.1%） patients had stage Ⅰ MCC, and 49 （28.6%）had stage Ⅱ MCC. One patient received immunotherapy, and 165 patients underwent surgical resection, including 91 patients receiving surgery alone, 24 patients treated with postoperative radiotherapy, 19 patients treated with postoperative chemotherapy, and 31 patients receiving postoperative chemoradiotherapy. Five patients did not describe the treatment. Among 74 patients who were followed up after the surgery, one-year survival rate and five-year survival rate were 52.7% and 6.8% respectively. The five-year survival rate was 6.1% in the patients with stage Ⅰ MCC, 5.6% in those with stage Ⅱ MCC, and 0 in those with stage Ⅲ and Ⅳ MCC. Conclusions In China, cutaneous MCC mostly occurs on the head, face, neck and extremities of the middle-aged or elderly, with a high misdiagnosis rate. Surgical excision combined with radiotherapy or chemotherapy is a frequently used treatment protocol in China, but the prognosis is always poor.

Key words: Carcinoma, Merkel cell, Antineoplastic combined chemotherapy protocols, Prognosis