Abstract:

Li Lijuan, Liu Jianying*, Su Jing, Gao Fei, Zheng Jie, Liao Songlin. *Department of Pathology, School of Basic Medical Sciences, Peking University; Department of Pathology, Peking University Third Hospital, Beijing 100191, China Corresponding author: Liu Jianying, Email: liujianying@bjmu.edu.cn 【Abstract】 Objective To analyze clinicopathologic features and malignant transformation of spiradenoma （SA）. Methods Clinicopathologic data on 25 cases of SA were retrospectively analyzed. An immunohistochemical study was conducted on 5 of the 25 patients. Clinicopathologic features of SA were summarized based on clinicopathologic data, immunohistochemical results and relevant literature. Results The average age of these patients was 40 years. Lesions were acquired and solitary in 24 cases （96%, 24/25）, and occurred most frequently in the extremities. The diameter of tumors was less than 2 cm in 20 cases （87%, 20/23）. Twenty-three cases were benign SA with various histological manifestations, including 15 cases （65%, 15/23） of typical SA, 8 cases （35%, 8/23） of cylindroma. Varying numbers of mitotic figures were observed in different cases. The immunohistochemical study showed epithelial and myoepithelial differentiation. Two cases of SA experienced malignant transformation into poorly-differentiated basal cell adenocarcinoma and well-differentiated adenocarcinoma respectively. Lymphocytes decreased significantly in number or disappeared in the malignant area, and both the malignant tumors exceeded 2 cm in diameter. Conclusions SA is a kind of neoplasm with distinct histological characteristics and nonspecific clinical manifestations. Most SA cases have a benign clinical course, but malignant transformation should be considered in some cases with long-term clinical course and large size.