Trichoblastoma and breast carcinoma as metachronous primary tumors: Case report.

Introduction And Importance: The occurrence of more than one tumor originating from the same or different organs is the definition of multiple primary tumors. According to the time of diagnosis, these tumors are classified into two types: metachronous and synchronous tumors. Trichoblastoma is a rare benign skin tumor that is rarely involved in multiple primary tumors, especially in patients with breast cancer.