Cutaneous squamous cell carcinoma (SCC) of the pinna is reported to have a higher rate of metastasis than cutaneous SCC originating from elsewhere - up to 16% compared with less than 2% for the latter. The authors aimed to assess the metastasis rate, the histological features of all SCC excised from the pinna between January 2002 to November 2012, and the outcome of the patients following surgery after at least two years’ follow-up. The authors looked at 192 patients who had an average age of 81 years. The majority were treated with surgical excision (147 patients) whilst 33 patients had surgical excision and radiotherapy and three patients radiotherapy alone. Fifteen patients required multiple excisions. The helix was the most frequent subsite for SCC to present although interestingly the majority (116 cases) did not record the exact subsite of the SCC on the pinna. Four patients developed metastasis all of which were within nine months of diagnosis and 24 patients had local recurrences.
The authors did not find any significant association between involved margins, lymphovascular invasion, cartilage invasion and ulceration with increased risk of metastasis. However, they did find a significant association between local recurrence, perineural invasion and poor histological differentiation with increased risk of metastasis.
The rate of metastasis found in this unit (2%) was much lower than that reported in the literature. The authors postulate that there may be regional differences in the metastatic rates of patients presenting with SCC of the pinna depending on the population treated, and more studies should be carried out across the UK prior to formulating a standardised criteria for prophylactic neck treatment in the country.