Cutaneous carcinoma of the auricular and periauricular region can be diagnosed early and often cured; however, many of these tumors become difficult to treat because of local spread and regional metastasis. We have treated 122 patients with 145 cutaneous carcinomas of the auricular and periauricular region with either Mohs' histographic surgery or conventional excision with total microscopic marginal control. Inherent in these treatment modalities is the construction of detailed serial tissue maps for each tumor. From these maps, a three-dimensional composite for each tumor is derived, giving information about the direction of local spread of the tumors. The tumors have been found to extend locally through soft tissue into perichondrial, periosteal, and neurovascular planes, allowing for more distant occult spread. This knowledge of such patterns of tumor spread can be useful in planning treatment.