Introduction: Non-melanoma skin cancer (NMSC) represents the most frequent malignancy in patients with solid organ transplantation, with a high risk of metastasis (MTS) and death  related to factors such as chronic immunosuppression, exposure to ultraviolet (UV) radiation, and HPV infections.

Objectives:

• To describe the features of non-melanoma skin cancer (NMSC).
• To report the development of multiple NSCLC and metastasis in patients treated with rapamycin.
• To  highlight the need for dermatological control in order to assess risk factors, precancerous lesions and make an early diagnosis.

Materials and methods: We present three renal transplant patients assisted  by Dermatology at the Renal Transplant Unit of CRAI Sur, Hospital Interzonal General de Agudos “Gral. San Martín”, La Plata, Argentina. Patients with multiple lesions under treatment with rapamycin and aggressive evolution were chosen. Risk factors related to the multiplicity and dismal evolution of NCC (signs of photodamage, preneoplastic lesions, history of NCC) were evaluated prior to evaluation at the unit; we also analysed age of presentation, sex, transplantation timing, initial immunosuppressive regimen and subsequent modifications, type of NMSC, treatment and evolution.

Patients: Case 1: 68 year-old  male, with prior history of basal cell carcinomas (back and face) and actinic keratoses. He developed multiple squamous cell carcinoma 5 years post transplantation. Induction: thymoglobulin. Immunosuppression: rapamycin, MMF and steroids. Therapy: surgery. Death due to multiple lung MTS. Case 2: 69 year-old male, with prior history of actinic keratoses and basal cell carcinoma (face). He developed  multiple metatypic basal cell carcinoma 9 years post-transplantation. Induction: Basiliximab. Immunosuppression: tacrolimus, MMF and steroids. Switch to rapamycin after diagnosis. Therapy: surgery and Imiquimod. Death due to acute myocardial infarction. Case 3: 43 year-old male, with prior history of actinic keratoses and squamous cell carcinoma (face). He developed  squamous cell carcinoma (face)  and  multiple skin MTS 7 years post-transplantation. Induction: thymoglobulin. Immunosuppression: tacrolimus, MMF and steroids. Switch to rapamycin after diagnosis. Therapy: chemotherapy. Death due to multiple lung MTS.

Conclusions:

1- The NMSC in these patients presented with multiple lesions and clinical and histological characteristics related to an aggressive course (MTS and death  in two cases).
2- Immunosuppressive therapy with rapamycin did not modify the outcome and development of multiple lesions despite its known antiproliferative  and  angiogenesis effects.
3- All our patients were men and presented risk factors for NMSC  (photodamage, actinic keratoses, more than five years post-transplantation, history of prior NMSC, induction and  immunosuppressive therapy).
4- Dermatological control is crucial in order to identify risk factors, promote photoeducation and make a prompt diagnosis.