Case of Bowen's disease accompanying syringofibroadenoma

Syringofibroadenoma is an extremely rare benign lesion with distinct histopathological features and variable clinical presentations. Most cases of syringofibroadenoma are thought to be benign skin appendage tumor with eccrine ductal differentiation, however, some syringofibroadenomas are suspected to be a reactive process. Herein, we report the first case of Bowen's disease accompanying syringofibroadenoma, which is suspected to be a reactive process, in a 78-year-old Japanese man. The precise nature of syringofibroadenoma accompanying carcinoma is still controversial. Syringofibroadenoma is thought to be a pre-existing neoplastic condition in some cases. In contrast, syringofibroadenoma is also considered to occur in a reactive process involving several inflammatory dermatoses and skin tumors, and the term "reactive syringofibroadenomatous hyperplasia" has been proposed. In this report, we summarize the clinicopathological features of carcinoma accompanying syringofibroadenoma and discuss the nature of syringofibroadenoma.