Cutaneous manifestations of malignant disease: a review

The skin is the largest and most accessible organ in the body. Internal malignancies can produce a wide range of cutaneous manifestations that are often neglected by clinicians. This review aims to increase the awareness of clinicians by highlighting the various cutaneous manifestations of common internal malignancies. A review composed via Medline Internet search, literature search and contributions from our experiences as well as shared experiences from colleagues over the years. The skin can be involved in systemic malignancy in a variety of ways: secondary spread; as part of a genetic or acquired syndrome; as a consequence of immunosupression or as paraneoplastic phenomena. The cutaneous markers of malignancy may occur before, at the same time as, or after the diagnosis of the tumour. While in some instances the skin lesion abates with the treatment of the primary tumour, relapse of a previously treated cutaneous disease can herald recurrence of the tumour. Systemic malignancies could, and do, produce a wide range of skin manifestations that are easily seen but often neglected by clinicians. A good understanding of these features will aid prompt and appropriate diagnosis, upon which the necessary treatment could be anchored.