A retrospective analysis of histological prognostic factors for the development of lymph node metastases from auricular squamous cell carcinoma

Aims: Squamous cell carcinoma (SCC) of the auricle has a high risk of metastatic spread, which is associated with high mortality. Identification of patients with a high risk of lymph node metastases would allow prophylactic treatment to the draining lymph nodes, but there are no established clinical or histopathological criteria to predict which tumours have a high risk of metastasis. The aim was to determine such criteria. Methods and results: The study was a retrospective analysis of the clinical and histological features of 229 cases of SCC of the auricle, with a minimum of 2 years' clinical follow-up. Overall, lymph node metastases were present in 24 cases (10.5%). Of the patients with metastatic disease 66.7% died, despite multi-modality treatment. Tumours with a depth of invasion > 8 mm or a depth of invasion between 2 and 8 mm in conjunction with evidence of destructive cartilage invasion, lymphovascular invasion or a non-cohesive invasive front had a high risk of metastasis (56% and 24%, respectively). Conclusions: Patients with high-risk tumours, as assessed histopathologically, should be considered for prophylactic therapy to or staging of the regional lymph nodes.