Cutaneous implantation metastasis complicating a superficial temporal-middle cerebral artery anastomosis

A 52-year-old patient who underwent a superficial temporal-middle cerebral artery anastomosis subsequently developed an unusual squamous cell carcinoma in the skin overlying the anastomosis. The pathological picture and course of events suggest that this tumor was implanted into deeper tissues at the time of operation. Systematic microscopically controlled operation (Mohs' chemosurgical technique) was required to preserve the anastomosis while completely extirpating the tumor.