Cutaneous metastases: Where do they come from and what can they mimic?

Cutaneous metastases have been described in up to 10% of malignancies. They usually occur after diagnosis of the primary tumour but can be synchronous or even precocious. Identification of the primary source of the metastasis can sometimes be difficult and this paper approaches this in two ways, firstly by discussing the most common types of metastases and secondly by looking at common histopathological patterns. Basic immunophenotypes are discussed. Metastatic lesions must also be distinguished from primary adnexal tumours, and the more common adnexal tumours mimicking metastases are discussed.