Cutaneous melanoma in solid organ transplant patients

Solid organ transplant patients are at greatly increased risk of developing a wide variety of skin cancers, particularly epithelial skin cancers. On the other hand, it is well known that an intact immune system limits the development of benign melanocytic lesions. The eruptive nevi phenomenon, which we can observe in solid organ transplant recipients, is indicative of the relationship between melanocyte proliferation and immune system. Regression of melanocytic nevi after restoration of complete immune responsiveness is a further clinical example the role of immunosurveillance on melanocyte proliferation. However, melanoma incidence in organ transplant recipients appears only 2-3 folds higher than in general population. To this regard, organ transplant recipients who develop de novo melanomas thicker than 2mm seem to have a significantly worse outcome with a greatly increased risk of dying of metastatic melanoma, whereas those who develop a ≤2 mm thickness melanoma seem to have a prognosis similar to that of the general population. Furthermore, there is no evidence supporting an increased risk of melanoma recurrences after transplant in patients with a history of low-risk melanoma. Melanoma is also one of the most frequent and lethal donor-derived malignancies suggesting that a history of invasive melanoma should be considered an absolute contraindication to donation. The aim of this review is to investigate the relationship between immunosuppression and melanoma and to discuss its clinical implications for the management of transplant-associated melanoma.