A case of carcinoma in situ of the lower lip successfully treated with shaving and photodynamic therapy.

Head and neck carcinoma in situ (CIS) is seldom diagnosed, and the causes are still unknown. Here, we report a case of a patient with CIS of the lower lip. After shaving combined with Photodynamic therapy (PDT) for three cycles, the patient was monitored for 16 months without recurrence. Therefore, shaving combined with PDT is a safe and effective treatment for CIS of the lower lip, and this approach may be suitable for more types of CIS in the future.