PATHOGENESIS

Cumulative ultraviolet radiation exposure, Fitzpatrick skin type, and cellular DNA repair capacity are key factors in the pathogenesis of cutaneous malignancies. In transplant recipients, long-term immunosuppression is clearly implicated in tumorigenesis. There is also evidence that certain immunosuppressive medications and human papillomavirus types are oncogenic.

INCIDENCE AND PREVENTION

Long-term transplant recipients have a markedly increased risk of developing squamous cell carcinoma (SCC). Because of extensive cumulative exposure to ultraviolet light, the dorsal hand is a common site for malignancies. Patients who are older and more than five years post transplant have a particular tendency to develop flat warts and keratotic lesions on the dorsal hands. SCC accounts for up to 90% of malignancies in this anatomic location. Although most SCC of the hands and fingers are effectively cured with standard surgical techniques, aggressive SCC of the hands and fingers may result in phalangeal, digital, or ray amputations, with consequent functional compromise. BCC of the hands is much less common than SCC, particularly in transplant patients.

CLINICAL PRESENTATION

Squamous cell carcinoma frequently presents as an indurated, inflamed, or painful keratotic nodule, often arising in photodamaged skin. SCC may clinically resemble hypertrophic actinic keratosis, verruca vulgaris, or stucco keratosis, though carcinoma is often distinguished by the presence of an indurated base, thickness, and pain. Basal cell carcinomas in transplant patients are clinically and histologically similar to those seen in immunocompetent patients.