Guidelines for prophylactic radical lymph node dissection in cases of carcinoma of the external ear

All cases of squamous-cell carcinoma of the external ear that were treated at the ENT Clinic, University Hospital, Lund, Sweden, between 1970 and 1977 were analyzed retrospectively to determine parameters for predicting the development of metastases. These cases included 62 males and 3 females, with a mean age of 77 years. The frequency of metastases for these patients was 16.4%. The carcinomas were graded according to four parameters: depth of growth, mode of invasion, cellular differentiation, and cellular plasmolymphocytic response. We concluded that depth of growth and mode of invasion were the most useful of these parameters and that prophylactic lymph node dissection should be performed in cases of tumors larger than 4 cm in diameter, of tumors infiltrating the cartilage, and of smaller tumors with maximum scores for depth of growth and mode of invasion.