[Depth of invasion of basaliomas]

The infiltration depths of 1421 basal cell carcinomas (BCC) were determined by means of the mid and basic sections of excised tumor specimens. According to our findings, BCC shows peripheral spreading in the majority of the cases. Deep infiltration primarily occurs in large tumors, scirrhous forms, tumors with exophytic growth or ulceration, and particularly in recurrent BCC. Because of the asymmetric infiltrative growth in depth, conventional evaluation of the mid-section does not provide satisfactory information on the question of radical removal in depth. Therefore, histological control of excisional margins is absolutely essential at least in the tumors mentioned above. The proportion of the tumors with subtotal excision in depth at the first operation was 5.9% for primary BCC and 14.8% for recurrent BCC. In almost all these cases, radical removal could be achieved by re-excision into a deeper layer.