The development of excess numbers of melanocytic naevi in an immunosuppressed identical twin.

The development of cutaneous proliferative lesions following renal transplantation has been well documented in the literature. Those lesions most commonly seen include viral warts, actinic keratoses and basal-cell and squamous-cell carcinomata. More recently it has been suggested that melanocyte proliferation, both benign and malignant, may follow renal transplantation, probably as a result of immunosuppression. We report the case of an identical twin who developed numerous benign melanocytic naevi following renal transplantation; no such proliferation of naevi occurred in his identical sibling.