Tumor invasion of the skin.

This article discusses several solid organ and hematologic neoplasms that can metastasize to the skin. Special emphasis is placed on the most frequent solid and hematological malignancies that have cutaneous metastases, including breast cancer, melanoma, lung cancer, colon cancer, and leukemia. In addition, mammary and extramammary Paget's disease are further discussed as examples of direct extension of primary tumors to the skin.