Squamous cell carcinoma of the external ear: 170 cases treated with Mohs surgery

Squamous cell carcinoma of the ear (SCC-E) shows high rates of local recurrence (LR) and lymph node metastases (NM). SCC-E is the leading cause of death from nonmelanoma skin cancer.

To determine the LR and NM rates and survival after Mohs micrographic surgery (MMS).

We treated 170 invasive SCC-E with MMS with a mean follow up of 48 months. Mean age was 76 years, 93.2% were male patients, mean size: 1.5 cm, and 61.8% of the tumours were well differentiated.

We observed 5 LRs, 2 locoregional recurrences, and 16 NMs in 23 patients. LR and NM rates were 4.1% and 10.6%, respectively. Only 3/25 recurrences occurred after 2 years of follow up. We observed 1(0.6%) distant metastasis (DM) in a patient who also presented LR + NM. Six out of seven cases with LR and 8/18 with NM died of disease, regardless of aggressive surgical rescue with or without adjuvant radiotherapy. Five-year overall survival, disease-free survival, and disease-specific survival were 81%, 82.6%, and 89.7%, respectively.

Undeniably, the outcome in SCC-E is determined by locoregional control. DM are sporadic and rarely the cause of death. Systematic reviews and retrospective studies show a solid trend in favor of MMS vs surgical excision. The LR rate of this series (4.1%) is one of the lowest published to date with regard to SCC-E, and confirms this assertion. We observed 10.6% NMs according to other series that treated the whole spectrum of SCC-E. Almost 2/3 of patients with NMs die after therapeutic rescue. We believe that it is essential to identify prognostic factors to select patients for one of the following: close surveillance (ultrasonography) during the first 2 years after surgery, sentinel node biopsy, or elective treatment of the nodes (surgery or radiotherapy).